@article {JRN55413, title = {Simulated distribution of Eragrostis lehmanniana (Lehmann lovegrass): Soil{\textendash}climate interactions complicate predictions}, journal = {Ecosphere}, volume = {13}, year = {2022}, month = {3/7/2022}, pages = {e3974}, abstract = {The invasive perennial grass Eragrostis lehmanniana has expanded rapidly throughout the Sonoran Desert (SD) while remaining sparse and patchily distributed in the neighboring Chihuahuan Desert (CD). As temperatures and patterns in precipitation change, identifying the drivers limiting spread in the CD is needed. Our objectives were (1) to identify the climatic and edaphic factors limiting recruitment of E. lehmanniana throughout the CD and (2) to predict the edaphic and climatic locations in the CD where this species is expected to have higher probabilities of recruitment under future climatic conditions. Recruitment was simulated at 57 locations throughout the CD with a daily, multilayer soil water model (SOILWAT) that was parameterized and tested to develop recruitment parameters for E. lehmanniana using long-term data from research stations in the SD and CD. Logistic regression was used to predict recruitment across the CD using climate and soil factors to create a map of simulated recruitment under current and alternative climate scenarios. Simulated recruitment under current climate was low for most of the CD. However, localized areas with high probabilities (>0.8) occurred along the western transition between the CD and the SD, and in the southern extent of the CD. In general, the CD climate is too cool and dry for rapid and widespread invasion. However, increases to temperature and precipitation are likely to increase recruitment success. Interactions among soil, tempera-ture, and precipitation were important to increases in recruitment of E. lehmanniana and are expected to lead to heterogeneous increases in abundance as climate continues to change. This patchy increase in abundance will result in changes in its geographic distribution that will make predictions in the future challenging.}, keywords = {Chihuahuan Desert, climate change, Geographic distribution, numerical model, recruitment, seedling establishment, Special Feature: Dynamic Deserts}, doi = {10.1002/ecs2.3974}, url = {files/bibliography/22-022.pdf}, author = {N. Dylan Burruss and Debra.C.P. Peters and Haitao Huang and Jin Yao} } @article {JRN55414, title = {Cross-Site comparisons of dryland ecosystem response to climate change in the US Long-Term Ecological Research Network}, journal = {BioScience}, volume = {72}, year = {2022}, month = {8/16/2022}, pages = {889-907}, abstract = {Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.}, keywords = {ANPP, climate change, disturbance, drought, LTER, wildfire}, doi = {https://doi.org/10.1093/biosci/biab134}, url = {files/bibliography/22-023.pdf}, author = {Amy R Hudson and Debra P C Peters and John M Blair and Daniel L. Childers and Peter T Doran and Kerrie Geil and Micheal Gooseff and Katherine L Gross and Nick Haddad and Melissa A Pastore and Jennifer A Rudgers and Osvaldo Sala and Eric W Seabloom and Gaius Shaver} } @proceedings {JRN55416, title = {Assessing grazing behavior of heritage, hybrid, and conventional cattle breeds in response to climate change}, year = {2022}, abstract = {Evidence suggests that heritage and hybrid beef cattle breeds exhibit more flexible foraging behaviors compared to highly selected conventional breeds. We hypothesize that these behaviors could be capitalized upon to support sustainability outcomes, such as biodiversity or climate change adaptation. We conducted a systematic search of studies that compared beef cattle breeds for behavioral traits and found 54 studies conducted since 1966 located in 9 of the 14 major terrestrial biomes, with 60 beef or dual-purpose breeds represented. We created a typology of the studies with respect to decade, continent, breed provenance (Continental, Criollo, Hybrid, B. indicus, Mediterranean, Sanga, British Isles), breed selection intensity (heritage [limited selection pressure], conventional [high selection pressure], hybrid [moderate selection pressure]), biome, study intent, and whether breeds met desired outcomes described by the study authors. Most studies (69\%) were conducted in arid rangeland settings in developed nations where researchers sought to minimize the negative environmental impacts of beef production. In comparisons of grazing behavior of heritage versus conventional types (n=25 studies), and hybrid versus conventional types (n=18 studies), heritage and hybrid cattle displayed more adapted traits (e.g., improved foraging distribution) in 88\% and 78\% of the studies, respectively. No differences were found in grazing behaviors in most studies in which heritage breeds were compared to other heritage breeds or conventional with conventional breeds (n=6 and 15 studies, respectively). In the subset of studies coded with the intent of {\textquotedblleft}foraging behavior,{\textquotedblright} heritage types traveled faster across a range of pasture sizes, which could indicate a capacity to seek high-quality nutrients while reducing trampling or overgrazing. Overall, our review suggests that breeds that have undergone moderate {\textendash} low selection pressure display grazing behaviors that demonstrate adaptation to their respective native environments and may help producers meet production goals in similar environments in the face of a changing climate.}, keywords = {behavior, cattle breeds, climate change, grazing, Heritage cattle, hybrid cattle}, author = {Matthew M. McIntosh and S. Spiegal and McIntosh, S. and Castano Sanchez, Jose and Richard E. Estell and Caitriana Steele and Emile H. Elias and C. Donovan Bailey and Joel R. Brown and Andr{\'e}s F. Cibils} } @article {JRN55284, title = {Declines in rodent abundance and diversity track regional climate variability in North American drylands}, journal = {Global Change Biology}, volume = {27}, year = {2021}, month = {5/4/2021}, pages = {4005-4023}, abstract = {Regional long-term monitoring can enhance the detection of biodiversity declines associated with climate change, improving future projections by reducing reliance on space-for-time substitution and increasing scalability. Rodents are diverse and important consumers in drylands, regions defined by the scarcity of water that cover 45\% of Earth{\textquoteright}s land surface and face increasingly drier and more variable climates. We analyzed abundance data for 22 rodent species across grassland, shrubland, ecotone, and woodland ecosystems in the southwestern USA. Two time series (1995-2006, 2004-2013) coincided with phases of the Pacific Decadal Oscillation (PDO), which influences drought in southwestern North America. Regionally, rodent species diversity declined 20-35\%, with greater losses during the later time period. Abundance also declined regionally, but only during 2004-2013, with losses of 5\% of animals captured. During the first time series (wetter climate), plant productivity outranked climate variables as the best regional predictor of rodent abundance for 70\% of taxa, whereas during the second period (drier climate), climate best explained variation in abundance for 60\% of taxa. Temporal dynamics in diversity and abundance differed spatially among ecosystems, with the largest declines in woodlands and shrublands of central New Mexico and Colorado. Which species were winners or losers under increasing drought and amplified interannual variability in drought depended on ecosystem type and the phase of the PDO. Fewer taxa were significant winners (18\%) than losers (30\%) under drought, but the identities of winners and losers differed among ecosystems for 70\% of taxa. Our results suggest that the sensitivities of rodent species to climate contributed to regional declines in diversity and abundance during 1995 - 2013. Whether these changes portend future declines in drought-sensitive consumers in the southwestern USA will depend on the climate during the next major PDO cycle.}, keywords = {biodiversity, climate change, Dipodomys, Onychomys, Peromyscus, small mammal, Standardized Precipitation Evapotranspiration Index}, doi = {10.1111/gcb.15672}, url = {files/bibliography/21-024.pdf}, author = {Pablo A. C{\'a}rdenas and Erica M. Christensen and Morgan Ernest and David C. Lightfoot and Robert L. Schooley and Paul Stapp and J.A. Rudgers} } @article {JRN55334, title = {Making research relevant: Sharing climate change research with rangeland advisors to transform results into drought resilience}, journal = {Rangelands}, volume = {RALA-00311}, year = {2021}, month = {10/1/2021}, pages = {1-9}, abstract = {On the Ground {\textbullet}Public programs, strategies, and incentives to implement rangeland climate adaptation are more effective if they are tailored to local drought exposures, sensitivities, and adaptation opportunities. As such, local rangeland advisers who aid in climate adaptation are pivotal to the development of these resources. {\textbullet} We hosted a virtual workshop with rangeland advisors to share results from our climate vulnerability assessment, gain their insight on finding usability, and discuss visions for resource creation. {\textbullet}Climate adaptation resources should not follow a one-size-fits-all approach. Accommodating variety in resource development and outreach must consider multiple factors: variation in the ranching community, instability in the environment beyond climate, and rancher/manager identified variables in climate vulnerability assessment analyses.}, keywords = {climate change, co-ideation, engagement, rangelands, workshop}, doi = {10.1016/j.rala.2021.08.004}, url = {files/bibliography/21-046.pdf}, author = {Maude Dinan and Peter B. Adler and James A. Bradford and M. Brunson and Emile H. Elias and Andrew Felton and Christina Greene and J. James and Katharine N. Suding and Eric Thacker} } @article {JRN55286, title = {Weight gain, grazing behavior and carcass quality of desert grass-fed Rar{\'a}muri Criollo vs. crossbred steers}, journal = {Livestock Science}, volume = {249}, year = {2021}, month = {10 April 2021}, abstract = {Rar{\'a}muri Criollo cattle producers often crossbreed their cows with improved beef-breed bulls and/or retain and develop their yearlings on rangeland because of limited weaned calf markets, however it is unknown if Rar{\'a}muri Criollo steers exhibit marketable weight gains and carcass qualities, or desirable grazing behaviors documented in cows of this biotype. We evaluated two cohorts (cohort: 1 = 31, 2 = 26) of Rar{\'a}muri Criollo (JRC), Mexican Criollo (MC) and Criollo {\texttimes} beef-breed crossbred (XC) steers to investigate effects of biotype on growth, carcass traits, and landscape utilization. Steers were weighed approximately once every 2-mo and average daily gains (ADG) calculated. Nine JRC and XC steers per cohort were monitored at 5-min intervals via global positioning systems (GPS) for 1-mo during winter (2015{\textendash}16) and late-summer (2016{\textendash}17). Weight and carcass data were analyzed using mixed measures procedures to identify differences between biotype through time. Discriminant analyses were conducted to determine whether grazing behaviors could be discriminated among: 1) JRC and XC steers and JRC cows; 2) steers by season (winter vs. summer); and 3) steers of cohort 1 and 2. Final live and carcass weights of XC were greater than JRC and MC, but all were market ready at 30-mo following a grass-finishing protocol. Carcass quality and ADG were not different among biotypes. Steers were discriminated into different season or cohort groups based on grazing behavior differences but JRC and XC steers exhibited grazing patterns that were similar to those previously observed in JRC cows. Our results suggest that JRC, MC, and XC steers can be developed to slaughter weights in 30-mo using a rangeland-based grass-fed protocol, and that JRC and XC steers exhibit desirable grazing behaviors previously observed in JRC cows.}, keywords = {beef cattle, climate change, Grass finished steers, Grass-fed supply-chain, Heritage genetics, livestock behavior}, issn = {1871-1413}, doi = {10.1016/j.livsci.2021.104511}, url = {files/bibliography/21-020.pdf}, author = {Matthew M. McIntosh and Andr{\'e}s F. Cibils and Richard E. Estell and S. Nyamuryekung{\textquoteright}e and Amy L. Gonzalez and Qixu Gong and Huiping Cao and S. Spiegal and S. Soto-Navarro and Amanda D.Blair} } @article {JRN55328, title = {Foraging behavior and body temperature of heritage vs. commercial beef cows in relation to desert ambient heat}, journal = {Journal of Arid Environments}, volume = {193}, year = {2021}, month = {6/20/2021}, pages = {104565}, abstract = {We studied foraging patterns of Raramuri Criollo (heritage breed, {\textquotedblleft}RC{\textquotedblright}) and Angus x Hereford (commercial beef breed, {\textquotedblleft}AH{\textquotedblright}) cows in relation to ambient heat and body temperature during summer (2016 and 2017) and winter (2017 and 2018) in the Chihuahuan Desert. Cows of each breed grazed separately in two adjacent pastures (~1100 ha) in a crossover design for four weeks in each season/year. Animals were fitted with temperature loggers attached to blank CIDRs (Controlled Internal Drug Release device) devoid of hormones that recorded body temperature (BodyT), and GPS collars that recorded position and ambient temperature (CollarT). All sensor data were logged at 10 min intervals. A landscape thermal map (LandT) was developed from Landsat satellite imagery for habitat analysis using GPS locations chosen by individual collared cows, and air temperature (AirT) was recorded by a nearby weather station. Data were analyzed within four daytime segments: dawn (sunrise {\textendash} 9AM); pre-noon (9AM {\textendash} noon); post-noon (noon {\textendash} 3PM); and dusk (3PM {\textendash} sunset). ANOVA was used to determine whether BodyT, CollarT, LandT selection, or animal movement variables within each of the four daily segments differed (P < 0.05) for RC vs. AH cows. BodyT and CollarT increased as day progressed in both seasons. During summer, RC had lower BodyT and higher CollarT than AH (P < 0.05) during the hottest hours of the day. Increasing AirT throughout the day was associated with selection of cooler LandT in RC but not AH during summer. In winter, both breeds selected warmer landscape locations as the day progressed. Compared to AH, RC cows traveled farther, at higher velocities, and spent more time grazing and traveling and less time resting, with largest breed differences observed during the hottest hours of summer days. These results suggest that Raramuri Criollo cows exhibited higher thermotolerance than did AH. Elevated ambient summer temperatures in the Chihuahuan Desert appear to impose fewer constraints on heritage RC movement patterns compared to mainstream commercial AH cows.}, keywords = {Chihuahuan Desert, climate change, Raramuri Criollo, thermotolerance}, doi = {10.1016/j.jaridenv.2021.104565}, url = {files/bibliography/21-038.pdf}, author = {S. Nyamuryekung{\textquoteright}e and Andr{\'e}s F. Cibils and Richard E. Estell and Matthew M. McIntosh and D. VanLeeuwen and Caitriana Steele and Amy L. Gonzalez and S. Spiegal and Leonel Avenda{\~n}o Reyes and Felipe A. Rodr{\'\i}g Almeida and Martha Anderson} } @article {JRN55265, title = {Snapshot of rancher perspectives on creative cattle management options}, journal = {Rangelands}, year = {2020}, month = {11/2020}, abstract = {A major challenge to successful management of livestock production in the western United States (U.S.) is coping with the extremely variable weather that dramatically affects forage availability. In addition, temperatures have already increased across the western U.S. and will continue to do so, creating even more challenging environmental conditions for future cattle production in the semi-arid and arid west . The Sustainable Southwest Beef project is a new Coordinated Agricultural Project led by New Mexico State University poised to identify viable options for arid lands ranchers and the U.S. beef industry as environmental challenges continue. The 5-year project is being conducted by a diverse team of nearly 30 research, education and extension specialists, focusing on three creative management strategies: precision ranching, heritage breeds and alternative supply chain options. A group of ranchers from the western U.S. advises the team (Figure 1). The Sustainable Southwest Beef team introduced the project to roughly 125 ranchers, feedlot operators and others connected to the beef cattle industry at the 2020 Southwest Beef Symposium in Amarillo, Texas and collected initial rancher perceptions of the three creative management strategies.}, keywords = {Beef production, climate change, Heritage cattle, precipitation, Precision livestock farming, Supply chain}, doi = {https://doi.org/10.1016/j.rala.2020.09.004}, url = {files/bibliography/20-033.pdf}, author = {Emile H. Elias and Skye Aney and G. Duff and Craig Gifford and S. Spiegal and Andr{\'e}s F. Cibils and Jean Steiner and Richard E. Estell} } @article {JRN55267, title = {A phenotypic characterization of Rar{\'a}muri Criollo cattle introduced into the southwestern United States}, journal = {Archivos Latinoamericanos De Produccion Animal}, volume = {28}, year = {2020}, month = {11/5/2020}, pages = {111-119}, abstract = {Our objective was to describe key phenotypic characteristics of a population of Rar{\'a}muri Criollo (RC) cattle introduced from the Copper Canyon of Chihuahua, M{\'e}xico into the Southwestern United States almost two decades ago. We recorded 26 phenotypic traits of 37 RC individuals including mature cows, first--calf heifers, and mature bulls raised at the USDA--ARS Jornada Experimental Range in southern New Mexico. This herd of RC cattle exhibited intermediate body sizes (390 kg) compared to the smaller Corriente (300 kg) and larger Texas Longhorn (400 kg) and Florida Cracker cattle (400 kg). Coat colors were similar to those described for other Criollo biotypes but horn shape and size of RC appear to be different than that of other US--based Criollo breeds. Though smaller than commercial beef breeds, RC cattle appear to be well -matched to the Southwestern US environments as evidenced by previous studies that evaluated their grazing behavior, weight gains, and carcass quality. Rar{\'a}muri Criollo cattle are a genetic resource whose conservation could be critically important for climate change adaptation of ranches in the desert Southwest. https://ojs.alpa.uy/index.php/ojs_files/article/view/2832}, keywords = {beef cattle, climate change, genetic conservation, heritage breed}, url = {files/bibliography/21-003.pdf}, author = {Matthew M. McIntosh and Amy L. Gonzalez and Andr{\'e}s F. Cibils and Richard E. Estell and S. Nyamuryekung{\textquoteright}e and A.F.A. Rodriguez and S. Spiegal} } @article {JRN55198, title = {Deciphering the past to inform the future: preparing for the next ({\textquotedblleft}really big{\textquotedblright}) extreme event}, journal = {Frontiers in Ecology and the Environment}, year = {2020}, month = {04/2020}, pages = {10.1002/fee.2194}, abstract = {

Climate change will bring more extremes in temperature and precipitation that will impact productivity and ecosystem resilience throughout agroecosystems worldwide. Historical events can be used to identify drivers that impact future events. A\  catastrophic drought in the US in the 1930s resulted in an abrupt boundary between areas severely impacted by the Dust Bowl and areas that were less severely affected. Historical primary production data confirmed the location of this boundary at the border between two\ states (Nebraska and Iowa). Local drivers of weather and soils explained production responses across the boundary before and after the drought (1926{\textendash}1948). During the drought, however, features at the landscape scale (soil properties and wind velocities) and regional scale (the Missouri River, its floodplain, and the nearby Loess Hills) explained most of the observed variance in primary production. The impact of future extreme events may be affected by land surface properties that either accentuate or ameliorate the effects of these events. Consideration of large-scale geomorphic processes may be necessary to interpret and manage for catastrophic events.

}, keywords = {agroecosystems, climate change, dust, dust bowl, future, historical, large-scale, regional-scale}, doi = {10.1002/fee.2194}, url = {bibliography/20-010.pdf}, author = {Debra C. Peters and N. Dylan Burruss and Gregory S. Okin and J. Hatfield and Stacey L P Scroggs and Haitao Huang and Colby Brungard and Jin Yao} } @article {JRN55137, title = {Climate change impacts on wind and water erosion on US rangelands}, journal = {Journal of Soil and Water Conservation}, volume = {74}, year = {2019}, month = {07/2019}, pages = {405-418}, chapter = {405}, abstract = {

Soil erosion by water and wind in US rangelands has serious implications for rangeland health, food security, and poses significant hazards to human health and communities. Accordingly, understanding how future climate change may impact soil erosion is critical for developing appropriate management strategies that mitigate negative impacts to the extent practical and potentially build resilience. Here, we review potential impacts of climate change on controls of erosion in US rangelands and discuss potential erosion responses. Projected climate changes are expected to have regionally variable effects on important controls of erosion, especially vegetation cover; community composition; frequency, magnitude, and geographical range of fire disturbance; and high intensity, erosive weather events, all of which have the potential to increase rangeland vulnerability to erosion. We identify knowledge gaps relevant to these controls and discuss management considerations to address climate change impacts to soil erosion concerns for US rangelands. We recommend using existing monitoring data to create assessments of vulnerability, that soil erosion should be explicitly included in management benchmarks and decision support tools, and that no-regrets management options be implemented in anticipation of future impacts, which can improve resilience and the efficacy of climate change adaptation.

}, keywords = {climate change, rangeland, soil erosion, water erosion, wind erosion}, doi = {doi.org/10.2489/jswc.74.4.405}, url = {files/bibliography/19-017.pdf}, author = {Brandon Edwards and Nicholas Webb and David A. Brown and Emile H. Elias and Dannele E. Peck and Frederick B. Pierson and Jason C. Williams and Jeffrey E. Herrick} } @article {JRN55158, title = {Long-term declining trends in Chihuahuan Desert forage production in relation to precipitation and ambient temperature}, journal = {Rangeland Ecology and Management}, volume = {72}, year = {2019}, month = {11/01/2019}, abstract = {

Rising temperatures and more frequent droughts are posing new challenges to range livestock producers in the southwestern United States and many other parts of the world. We analyzed a 49-year time series (1969-2017) of precipitation, ambient temperature, and perennial grass production (PGP) as well as 14 years (2001-2014) of MODIS-derived vegetation phenometrics at a site in the Chihuahuan Desert of New Mexico. PGP was positively associated with December through September precipitation (r = 0.74; P \< 0.05) but negatively associated
with spring and summer (Mar-Sep) maximum average ambient temperature (r = -0.54; P \< 0.05). PGP decreased by 38\% in the second (1994-2017) compared to first half (1969-1993) of our study (228 \± 36.75 vs. 141 \± 21.97 kg DM*ha-144 ; P \< 0.01). Precipitation was lower and more erratic in the second half of the time series decreasing by 21\% (264.88 \± 1.30 vs. 211.13 \± 16.67 mm; P = 0.01). Conversely, mean maximum and mean ambient temperatures were higher during the 1994-2017 period (max T: 24.48 \± 0.14 vs. 25.22 \± 0.13\°C; P \< 0.01; mean T:14.45 \± 0.13 vs. 15.04 \± 0.13\°C; P \< 0.01). MODIS-derived NDVI analysis showed that growing seasons began and ended later and became shorter (P \< 0.05) over the 14 years analyzed. During this period, increasing maximum summer (Jun-Sep) ambient temperatures were associated with decreasing growing season NDVI values (P \< 0.01). Over the 49-year study period, Chihuahuan Desert rangelands at our research site lost 38\% of grazing capacity. Nine drought years occurred in the second half of our study compared to two in the first half. Our research supports predictions by climate scientists that more frequent droughts and lower as well as more erratic precipitation will adversely impact grazing capacity of rangelands in the southwestern United States.

}, keywords = {climate change, forage, grazing capacity, NDVI, phenometrics}, doi = {10.1016/j.rama.2019.06.002}, url = {files/bibliography/19-025.pdf}, author = {Matthew M. McIntosh and Jerry L. Holechek and S. Spiegal and Andr{\'e}s F. Cibils and Richard E. Estell} } @article {JRN55147, title = {Spatio-temporal variation of crop loss in the United States from 2001 to 2016}, journal = {Environmental Research letters}, volume = {14}, year = {2019}, month = {07/2019}, pages = {1-12}, chapter = {1}, abstract = {

Crop insurance loss data can illuminate variations in agricultural impacts from exposure to weather and climate-driven events, and can improve our understanding of agricultural vulnerabilities. Here we perform a retrospective analysis of weather and climate-driven reasons for crop loss (i.e. cause of loss) obtained from the Risk Management Agency of the United States Department of Agriculture. The federal crop insurance program has insured over $440 billion in liabilities representing farmers{\textquoteright} crops from 2001 to 2016. Specifically, we examine the top ten weather and climate-driven causes of loss from 2001 to 2016 across the nation comprising at least 83\% of total indemnities (i.e. insurance payouts provided to farmers after crop loss events). First, we analyzed the relative fraction of indemnities by causes of loss, over different spatial and temporal resolutions. We found that drought and excess precipitation comprised the largest sources of crop loss across the nation. However, these causes varied strongly over space and time. We applied two additional normalization techniques to indemnities using (1) insurance premia and the gross domestic product implicit price deflator, and (2) liabilities to calculate the loss cost. We conducted trend analyses using the Mann{\textendash}Kendall statistical test on loss cost over time. Differential trends and patterns in loss cost demonstrated the importance of spatio-temporal resolution in assessing causes of loss. The majority of monthly significant trends (p \< 0.05) showed increasing loss cost (i.e. increasing indemnities or decreasing liabilities) in response to weather events. Finally, we briefly discuss an online portal (AgRisk Viewer) to make these data accessible at multiple spatial scales and sub-annual time steps to support both research and outreach efforts promoting adaptation and resilience in agricultural systems.

}, keywords = {adaptation, agriculture, climate change, crop insurance, drought, extreme weather, vulnerability}, doi = {doi.org/10.1088/1748-9326/ab1ac9}, url = {files/bibliography/19-018.pdf}, author = {J.T. Reyes and Emile H. Elias} } @article {JRN55145, title = {Extreme weather events and transmission losses in arid streams}, journal = {Environmental Research Letters}, volume = {14}, year = {2019}, pages = {084002}, abstract = {

A limited understanding of how extreme weather events affect groundwater hinders our ability to predict climate change impacts in drylands, where channel transmission losses are often the primary recharge mechanism. In this study, we investigate how potential changes to precipitation intensity and temperature will affect the water balance of a typical first-order, arid watershed located in the Chihuahuan Desert. We utilize a process-based hydrologic model driven by stochastically-downscaled simulations from a set of climate models, emissions scenarios, and future periods. Across many simulations, the average daily storm size is the primary factor that controls transmission losses with larger precipitation amounts increasing channel infiltration while simultaneously decreasing land surface evapotranspiration. Extreme events (\>25 mm d-1) that account for less than 30\% of the annual precipitation, contribute almost 50\% of the focused recharge. As a result, climatic changes leading to larger, less frequent storms will result in higher channel transmission losses in arid regions.

}, keywords = {channel transmission losses, climate change, distributed hydrologic modeling, dryland ecohydrology, extreme events, groundwater recharge, hydrology, hydrology model, water balance}, doi = {10.1088/1748-9326/ab2949}, url = {files/bibliography/19-019_0.pdf}, author = {A. P. Schreiner-McGraw and Ajami, Hoori and Enrique Vivoni} } @article {JRN54931, title = {County-level climate change information to support decision-making on working lands within USDA Climate Hub regions}, journal = {Climatic Change}, volume = {148}, year = {2018}, month = {06/2018}, pages = {355{\textendash}369}, chapter = {3}, abstract = {

Farmers, ranchers, and forest landowners across the USA make weather- and climate-related management decisions at varying temporal and spatial scales, often with input from local experts like crop consultants and cooperative extension (CE) personnel. In order to provide additional guidance to such longer-term planning efforts, we developed a tool that shows statistically downscaled climate projections of temperature and precipitation consolidated to the county level for the contiguous US. Using the county as a fundamental mapping unit encourages the use of this information within existing institutional structures like CE and other U.S. Department of Agriculture (USDA) programs. A {\textquotedblleft}quick-look{\textquotedblright} metric based on the spatial variability of climate within each county aids in the interpretation of county-level information. For instance, relatively higher spatial variability within a county indicates that more localized information should be used to support stakeholder planning. Changes in annual precipitation show a latitudinal dipole where increases are projected for much of the northern US while declines are projected for counties across the southern US. Seasonal shifts in county-level precipitation are projected nationwide with declines most evident in summer months in most regions. Changes in the spatial variability of annual precipitation for most counties were less than 10\ mm, indicating fairly spatially homogenous midcentury precipitation changes at the county level. Annual and seasonal midcentury temperatures are projected to increase across the USA, with relatively low change in the spatial variability (\<0.3\ {\textdegree}C) of temperature across most counties. The utility of these data is shown for forage and almond applications, both indicating a potential decline in production in some future years, to illustrate use of county-level seasonal projections in adaptation planning and decision-making.

}, keywords = {agriculture, climate change, Cooperative extension, decision-making, forestry, ranching, USDA climate hubs}, doi = {doi.org/10.1007/s10584-017-2040-y}, url = {files/bibliography/18-024.pdf}, author = {Emile H. Elias and Scott T. Schrader and John T Abatzoglou and D. K. James and Michael Crimmins and Weiss, Jeremy and A. Rango} } @article {JRN54846, title = {Groundwater recharge in desert playas: current rates and future effects of climate change}, journal = {Environmental Research Letters}, volume = {13 014025}, year = {2018}, month = {01/2018}, pages = {10 pp.}, abstract = {

Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause up to a 300\% increase in annual groundwater recharge beneath playas. This increase will overshadow the effect of decreased precipitation amount that could cause up to a 50\% decrease in recharge beneath playas. These changes could have a significant impact on groundwater and carbon storage. These results are important given that groundwater resources in Southwestern USA continue to decline due to human consumption outpacing natural recharge of aquifers. Here, we report on groundwater recharge rates ranging from less than 1 mm to greater than 25 mm per year beneath desert playas. Playas located in larger and steeper catchments with finer-textured soils had the highest rates of recharge. Vegetation cover had no effect on recharge beneath playas.We modeled catchment runoff generation and found that the amount of runon a playa receives annually strongly correlated to the rate of groundwater recharge beneath that playa. Runon occurred during precipitation events larger than 20 mm and increased linearly with events above that threshold.

}, keywords = {climate change, desert playas, groundwater recharge, Jornada LTER, precipitation variability, runoff modeling, watershed ecology}, doi = {https://doi.org/10.1088/1748-9326/aa9eb6}, url = {/files/bibliography/18-001.pdf}, author = {Owen P. McKenna and O. E. Sala} } @article {JRN54899, title = {Playa-wetlands effects on dryland biogeochemistry: space and time interactions}, journal = {Journal of Geophysical Research - Biogeosciences}, year = {2018}, abstract = {

Playas are ephemerally flooded wetlands found in hydrologically closed dryland catchments. Recent research showed how upland-catchment biophysical characteristics control the amount of organic carbon and nutrients that accumulates in playas from upland grasslands and shrublands. Here we further explored the role of allochthonous and autochthonous processes in fixing carbon and accruing soil nutrients in playas across a desert basin. We assessed whether playas contribute soil nutrient, organic-carbon stocks, and primary productivity rates in amounts disproportionately higher or lower than upland grasslands and shrublands. We found that playas had higher soil carbon and nutrient storage but no difference in mean annual primary production. Playas, on average, had similar primary productivity than upland systems, because they exhibited lower productivity during extremely wet years that offset the larger productivity during average or below average precipitation years. These results suggest that playas contain higher carbon and soil nutrient stocks because of runoff-mediated allochthonous inputs, rather than autochthonous sources, since long-term average productivity was similar to upland ecosystems. We also used the precipitation-aboveground net primary production (ANPP) relationships to accurately measure run-on in playas using differences between playa and upland grassland ANPP. The dependence of playa ANPP on surface-water inputs from upland catchments makes them susceptible to future changes in extreme precipitation events.

}, keywords = {climate change, desert playas, groundwater recharge, Jornada LTER, organic carbon, precipitation variability, soil nutrients, watershed ecology}, doi = {10.1029/2017JG004176}, url = {files/bibliography/JRN54899.pdf}, author = {Owen P. McKenna and O. E. Sala} } @article {JRN54629, title = {Global-change drivers of ecosystem functioning modulated by natural variability and saturating responses}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {503-511}, abstract = {

Humans are altering global environment at an unprecedented rate through changes in biodiversity, climate, nitrogen cycle, and land use. To address their effects on ecosystem functioning, experiments most frequently explore one driver at a time and control as many confounding factors as possible. Yet, which driver exerts the largest influence on ecosystem functioning and whether their relative importance changes among systems remain unclear. We analyzed experiments in the Patagonian steppe that evaluated the aboveground net primary production (ANPP) response to manipulated gradients of species richness, precipitation, temperature, nitrogen fertilization (N), and grazing intensity. We compared the effect on ANPP relative to ambient conditions considering intensity and direction of manipulations for each driver. The ranking of responses to drivers with comparable manipulation intensity was as follows: biodiversity\>grazing\>precipitation\>N. For a similar intensity of manipulation, the effect of biodiversity loss was 4.0, 3.6, and 1.5, times larger than N deposition, decreased precipitation, and increased grazing intensity. We interpreted our results considering two hypotheses. First, the response of ANPP to changes in precipitation and biodiversity is saturating, so we expected larger effects when the driver was reduced, relative to ambient conditions, than when it was increased. Experimental manipulations that reduced ambient levels had larger effects than those that increased them. Second, the sensitivity of ANPP to each driver is inversely related to the natural variability of the driver. In Patagonia, the ranking of natural variability of drivers is as follows: precipitation\>grazing\>temperature\>biodiversity\> N. So, in general, the ecosystem was most sensitive to drivers that varied the least. Comparable results from Cedar Creek (MN) support both hypotheses and suggest that sensitivity to drivers varies among ecosystem types. Given the importance of understanding ecosystem sensitivity to predict global-change impacts, it is necessary to design new experiments located in regions with contrasting natural variability and that include the full range of drivers.

}, keywords = {ANPP, biodiversity loss, climate change, ecosystem sensitivity, land-use change, nitrogen deposition}, doi = {10.1111/gcb.13441}, url = {files/bibliography/JRN00656.pdf}, author = {P. Flombaum and Laura Yahdjian and O. E. Sala} } @article {JRN54630, title = {Direct effects dominate responses to climate perturbations in grassland plant communities}, journal = {Nature Communications}, year = {2016}, pages = {1-10}, abstract = {

Theory predicts that strong indirect effects of environmental change will impact communities when niche differences between competitors are small and variation in the direct effects experienced by competitors is large, but empirical tests are lacking. Here we estimate negative frequency dependence, a proxy for niche differences, and quantify the direct and indirect effects of climate change on each species. Consistent with theory, in four of five communities indirect effects are strongest for species showing weak negative frequency dependence. Indirect effects are also stronger in communities where there is greater variation in direct effects. Overall responses to climate perturbations are driven primarily by direct effects, suggesting that single species models may be adequate for forecasting the impacts of climate change in these communities.

}, keywords = {black grama grass, Bouteloua eripoda, chart quadrat data, climate change, climate perturbations, environmental change, grass communities, model}, doi = {10.1038/ncomms11766}, url = {/files/bibliography/16-016.pdf}, author = {Chu, Chengjin and Kleinhesselink, Andrew R. and Kris Havstad and M.P. McClaran and Debra C. Peters and Vermeire, Lance T. and Wei, Haiyan and Peter B. Adler} } @article {JRN54627, title = {Climate change, agriculture and water resources in the Southwestern United States}, journal = {Journal of Contemporary Water Research and Education}, year = {2016}, month = {08/2016}, pages = {46-61}, abstract = {

In February 2014 the USDA established regional climate hubs across the United States to assist farmers, ranchers and foresters in adapting to the effects of climate change. The Southwest (SW) region encompasses six states which provide highly diverse agricultural crops including cotton, stone fruit and grapes. Here we report on the establishment of programs to assist SW working landowners with the impacts of climate change, with focus on the water resources of the region. Water is a critical component of agricultural vulnerability in the SW, where high agricultural production can occur with sufficient irrigation. Since 1978, crop yield declines were reported on 11-21\% of total irrigated acres, mostly due to surface water shortage. Southwestern agriculture relies heavily on groundwater, using it to supply more than one-third of the agricultural water demand since 1955. Regional groundwater use varies over time, with a decline in the agricultural groundwater fraction in Arizona, but an increase in the fraction in Nevada and Utah. Observed and predicted changes in the southwestern hydrologic cycle can impact regional agriculture. Observed records show an increase in the fraction of precipitation falling as rain, which is expected to continue with future warming. Warming causes the snowmelt to peak earlier in the season and can reduce water available to crops during the summer months without additional water storage. Observed records indicate streamflow has shifted earlier in the year, most notably in snow dominated watersheds a continuation of this trend may challenge regional agriculture by further limiting water supply.

}, keywords = {agriculture, climate change, Southwest Climate Hub, water resources}, url = {files/bibliography/16-017.pdf}, author = {Emile H. Elias and A. Rango and Ryann Smith and Connie J. Maxwell and Caitriana Steele and Kris Havstad} } @article {JRN54501, title = {Assessing climate change impacts on water availability of snowmelt-dominated basins of the Upper Rio Grande Basin}, journal = {Journal of Hydrology: Regional Studies }, volume = {3}, year = {2015}, month = {05/2015}, pages = {525-546}, chapter = {525}, abstract = {

Study Region- Upper Rio Grande, Colorado and New Mexico, USA: Climate change is predicted to further limit the water availability of the arid southwestern U.S. In this study, the Snowmelt Runoff Model is used to evaluate impacts of increased temperature and altered precipitation on snow covered area, streamflow timing and seasonal and total volume in the Upper Rio Grande.\  Simulations investigate a fairly hot and dry future condition at the end of the 21st century using a regionally recommended general circulation model downscaled to existing climate stations. Twenty-four subbasins of the Upper Rio Grande containing appreciable snowmelt and a long-term gauging station are simulated. \ \ New Hydrological Insights for the Region: Total basin snow covered area decreased by 55\% due to future temperatures. SRM simulation shows that total annual 2099 volume for all basins was between 13\% and 33\% lower than 1999 total annual volume. Among the 24 basins there is considerable range in decrease in snow covered area (6-87\%), total volume reduction (4-34\%) and runoff timing shift (0-60 days early) indicating that climate change impacts are best evaluated at the sub-basin scale. Daily hydrographs show higher streamflow in March and April, but less from mid-May until the end of the water year.\  The large decrease in volume in May, June and July will compound water management challenges in the Upper Rio Grande.

}, keywords = {climate change, snowmelt runoff model, Upper Rio Grande, water resources}, doi = {10.1016/j.ejrh.2015.04.004}, url = {/files/bibliography/15-021.pdf}, author = {Emile H. Elias and A. Rango and Caitriana Steele and Mejia, John and Ryann Smith} } @article {JRN54386, title = {Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity}, journal = {Ecology Letters}, volume = {18}, year = {2015}, pages = {1293-1300}, abstract = {

Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.

}, keywords = {arid zones, climate change, ecosystem functioning, functional diversity, grassland, interannual, precipitation variability, productivity, stability}, doi = {10.1111/ele.12523}, url = {/files/bibliography/15-028.pdf}, author = {Laureano A. Gherardi and O. E. Sala} } @article {JRN54167, title = {Enhanced precipitation variability effects on water losses and ecosystem functioning: differential response of arid and mesic regions}, journal = {Climate Change}, volume = {131}, year = {2015}, month = {07/2015}, pages = {213-227}, chapter = {213}, abstract = {

Climate change will result in increased precipitation variability with more extreme events reflected in more frequent droughts as well as more frequent extremely wet conditions. The increase in precipitation variability will occur at different temporal scales from intra to inter-annual and even longer scales. At the intra-annual scale, extreme precipitation events will be interspersed with prolonged periods in between events. At the inter-annual scale, dry years or multi-year droughts will be combined with wet years or multi-year wet conditions. Consequences of this aspect of climate change for the functioning ecosystems and their ability to provide ecosystem services have been underexplored. We used a process-based ecosystem model to simulate water losses and soil-water availability at 35 grassland locations in the central US under 4 levels of precipitation variability (control, +25, +50+75 \%) and six temporal scales ranging from intra- to multi-annual variability. We show that the scale of temporal variability had a larger effect on soil-water availability than the magnitude of variability, and that inter- and multi-annual variability had much larger effects than intraannual variability. Further, the effect of precipitation variability was modulated by mean annual precipitation. Arid-semiarid locations receiving less than about 380 mm yr-1 mean annual precipitation showed increases in water availability as a result of enhanced precipitation variability while more mesic locations (\>380 mm yr-1) showed a decrease in soil water availability. The beneficial effects of enhanced variability in arid-semiarid regions resulted from a deepening of the soil-water availability profile and a reduction in bare soil evaporation. The deepening of the soil-water availability profile resulting from increase precipitation variability may promote future shifts in species composition and dominance to deeper-rooted woody plants for ecosystems that are susceptible to state changes. The break point, which has a mean of 380-mm with a range between 440 and 350 mm, is remarkably similar to the 370-mm threshold of the inverse texture hypothesis, below which coarse-texture soils had higher productivity than fine-textured soils.

}, keywords = {climate change, drought, model, precipitation variability, rainfall variability, soil-water availability}, doi = {10.1007/s10584-015-1389-z}, url = {/files/bibliography/15-013.pdf}, author = {O. E. Sala and Laureano A. Gherardi and Debra C. Peters} } @article {JRN54388, title = {Quantifying how short-term environmental variation leads to long-term demographic responses to climate change}, journal = {Journal of Ecology}, year = {2015}, pages = {1-12}, abstract = {

1. Climate change is expected to alter not only year-to-year variation in climate but also aspects of within-year variation, such as the length of the intervals between rainfall events and the duration of heat waves. Yet we still have a poor understanding of how intra-annual climate variability and individual weather events alter key vital rates (e.g. individual growth, reproduction and survival) that in part determine population dynamics.

2. Traditionally, ecologists have accounted for this variability across long time periods by attempting to correlate annual vital rates with measures of within-year variability (e.g. the coefficient of variation) to match the scale at which demographic data are collected. An alternative to this aggregate approach is to use within-season yet still relatively infrequent censuses in a probabilistic framework to determine the most likely way that vital rates respond to shorter-term variation in the environment, and how these short-term changes cumulatively lead to the observed yearly vital rates.

3. Here, I present an approach for inferring daily responses of vital rates to short-term weather variability, and apply it to understand how five species of summer annual plants in the Chihuahuan Desert will respond to climate change.

4. Vital rate models reveal that species differ in their responses to above- and below-average conditions, but generally fall into two life histories: (i) species that have fast growth on favourable days, but also experience higher mortality on less favourable days, and (ii) species that have slower growth in the same conditions but lower mortality. Results show that the expected rainfall changes in the Chihuahuan Desert (more late, cool season rainfall and less frequent, more intense rainfall events) could reduce growth and increase mortality of all summer annual plants.

5. Synthesis. My study shows that vital rates can change in response to short-term variability even when the total amount of rainfall and average temperature, common covariates in demographic models, remain constant. Accounting for changes in short-term environmental variation in climate change predictions will likely be important in systems with considerable environmental variation between censuses. The approach I present here can be widely applied to understand how short-term variability and individual weather events will alter organism responses to climate change.

}, keywords = {annual plants, Chihuahuan Desert, climate change, demography, intra-annual variability, missing data, plant{\textendash}climate interactions}, doi = {10.1111/1365-2745.12490}, author = {Shriver, Robert K.} } @article {JRN53910, title = {Savory{\textquoteright}s unsubstantiated claims should not be confused with multipaddock grazing}, journal = {Rangelands}, volume = {36}, year = {2014}, month = {02/2014}, pages = {39-42}, type = {Letter to the Editor}, chapter = {39}, abstract = {

Letters to the Editor: The sole objective of our critique of Mr Savory{\textquoteright}s TED video published in Rangelands1 was to {\textquotedblleft}fact check{\textquotedblright} a portion of the extraordinary claims that he had made relative to sciencebased information. It is incumbent upon a professional discipline to evaluate the relevant evidence and potential viability of proposed management strategies and policies. Regrettably, Richard Teague{\textquoteright}s response does not address any of Mr Savory{\textquoteright}s claims that we addressed in our critique{\textemdash}not all global rangelands are degraded, rangelands have a limited capacity to store carbon, and intensive rotational grazing is not necessary to prevent rangelands from degrading. Here we reiterate these last two points of our initial critique, then address the concerns presented by Teague, and conclude with comments regarding the future direction of grazing systems research.

}, keywords = {climate change, desertification, planned grazing, Savory Method}, doi = {10.2111/1551-501X-36.1.39 }, url = {/files/bibliography/14-008.pdf}, author = {D.D. Briske and Brandon T Bestelmeyer and Joel R. Brown} } @article {JRN54038, title = {Functional response of U.S. grasslands to the early 21st-century drought}, journal = {Ecology}, volume = {95}, year = {2014}, month = {08/2014}, pages = {2121-2133}, chapter = {2121}, abstract = {

Grasslands across the United States play a key role in regional livelihood and national food security. Yet, it is still unclear how this important resource will respond to the prolonged warm droughts and more intense rainfall events predicted with climate change. The early 21st-century drought in the southwestern United States resulted in hydroclimatic conditions that are similar to those expected with future climate change. We investigated the impact of the early 21st-century drought on aboveground net primary production (ANPP) of six desert and plains grasslands dominated by C4 (warm season) grasses in terms of significant deviations between observed and expected ANPP. In desert grasslands, drought-induced grass mortality led to shifts in the functional response to annual total precipitation (PT), and in some cases, new species assemblages occurred that included invasive species. In contrast, the ANPP in plains grasslands exhibited a strong linear function of the current-year PT and the previous-year ANPP, despite prolonged warm drought. We used these results to disentangle the impacts of interannual total precipitation, intra-annual precipitation patterns, and grassland abundance on ANPP, and thus generalize the functional response of C4 grasslands to predicted climate change. This will allow managers to plan for predictable shifts in resources associated with climate change related to fire risk, loss of forage, and ecosystem services.

}, keywords = {climate change, desert, extreme events, grassland production, invasive species, plains, precipitation variability, resilience, warm drought}, doi = {10.1890/13-1687.1}, url = {/files/bibliography/14-025.pdf}, author = {S. Moran and Guillermo E. Ponce-Campos and Alfredo Huete and M.P. McClaran and Yongguang Zhang and Hamerlynck, Erik and D.J. Augustine and Stacey A. Gunter and S.G. Kitchen and Debra C. Peters and Paul F. Starrs and Mariano Hernandez} } @article {JRN54130, title = {Quantifying drylands{\textquoteright} drought resistance and recovery: the importance of drought intensity, dominant life history and grazing regime}, journal = {Global Change Biology}, year = {2014}, pages = {1-16}, abstract = {

Projected global change will increase the level of land-use and environmental stressors such as drought and grazing, particularly in drylands. Still, combined effects of drought and grazing on plant production are poorly understood, thus hampering adequate projections and development of mitigation strategies. We used a large, cross-continental database consisting of 174 long-term datasets from \>30 dryland regions to quantify ecosystem responses to drought and grazing with the ultimate goal to increase functional understanding in these responses. Two key aspects of ecosystem stability, resistance to and recovery after a drought, were evaluated based on standardized and normalized aboveground net primary production (ANPP) data. Drought intensity was quantified using the standardized precipitation index. We tested effects of drought intensity, grazing regime (grazed, ungrazed), biome (grassland, shrubland, savanna) or dominant life history (annual, perennial) of the herbaceous layer to assess the relative importance of these factors for ecosystem stability, and to identify predictable relationships between drought intensity and ecosystem resistance and recovery. We found that both components of ecosystem stability were better explained by dominant herbaceous life history than by biome. Increasing drought intensity (quasi-) linearly reduced ecosystem resistance. Even though annual and perennial systems showed the same response rate to increasing drought intensity, they differed in their general magnitude of resistance, with annual systems being ca. 27\% less resistant. In contrast, systems with an herbaceous layer dominated by annuals had substantially higher postdrought recovery, particularly when grazed. Combined effects of drought and grazing were not merely additive but modulated by dominant life history of the herbaceous layer. To the best of our knowledge, our study established the first predictive, cross-continental model between drought intensity and drought-related relative losses in ANPP, and suggests that systems with an herbaceous layer dominated by annuals are more prone to ecosystem degradation under future global change regimes.

}, keywords = {ANPP, climate change, cross-continental, cross-site, drought, drylands, model, recovery, resilience, resistance, stability}, doi = {10.1111/gcb.12777}, author = {Ruppert, Jan C. and Harmoney, Keith and Henkin, Zalmen and Snyman, Hennie A. and Marcelo Sternberg and Walter Willms and Linstadter, Anja} } @article {JRN54396, title = {Soil animal responses to moisture availability are largely scale, not ecosystem dependent: Insight from a cross-site study}, journal = {Global Change Biology}, volume = {20}, year = {2014}, month = {02/2014}, pages = {2631-2643}, chapter = {2631}, abstract = {

Climate change will result in reduced soil water availability in much of the world either due to changes in precipitation or increased temperature and evapotranspiration. Responses of communities of mites and nematodes to changes in moisture availability are not well known, yet these organisms play important roles in decomposition and nutrient cycling processes. We determined how communities of these organisms respond to changes in moisture availability and whether common patterns occur along fine-scale gradients of soil moisture within four individual ecosystem types (mesic, xeric and arid grasslands and a polar desert) located in the western United States and Antarctica, as well as across a cross-ecosystem moisture gradient (CEMG) of all four ecosystems considered together. An elevation transect of three sampling plots was monitored within each ecosystem and soil samples were collected from these plots and from existing experimental precipitation manipulations within each ecosystem once in fall of 2009 and three times each in 2010 and 2011. We found that while both mites and nematodes increased with available soil moisture across the CEMG, within individual ecosystems increases in soil moisture resulted in decreases to nematode communities at all but the arid grassland ecosystem; mites showed no responses at any ecosystem. Changes in proportional abundances of mite and nematode trophic groups as soil moisture increased within individual ecosystems may result in shifts within soil food webs with important consequences for ecosystem functioning. We suggest that communities of soil animals at local scales may respond predictably to changes in moisture availability regardless of ecosystem type but that additional factors, such as climate variability, vegetation composition and soil properties may influence this relationship over larger scales.

}, keywords = {climate change, desert, drought, grassland, mites, nematodes}, doi = {10.1111/gcb.12522}, url = {/files/bibliography/14-037.pdf}, author = {Sylvain, Zachary A. and D.H. Wall and Karie Cherwin and Lara Reichmann and Debra C. Peters and O. E. Sala} } @article {49839, title = {The Savory Method can not green deserts or reverse climate change}, journal = {Rangelands}, volume = {35}, year = {2013}, pages = {72-74}, abstract = {

This is a refutation of Allan Savory claims that his "planned grazing" method was necessary to reverse desertification and climate change as presented in the video "How to green the world{\textquoteright}s deserts and reverse climate change" that was presented in session 7 at the 2013 TED (Technology, Entertainment, Design) Conference on 27 February 2013 in Long Beach, California.

Allan Savory stated that his {\textquotedblleft}planned grazing{\textquotedblright} method was necessary to reverse two of the world{\textquoteright}s most challenging and interlinked global change processes{\textemdash}desertification and climate change{\textemdash}in the video {\textquotedblleft}How to green the world{\textquoteright}s deserts and reverse climate change{\textquotedblright} that was presented in session 7 at the 2013 TED (Technology, Entertainment, Design) Conference on 27 February 2013 in Long Beach, California.i As members of the scientific community, it is our obligation to evaluate the claims made in this video relative to the existing scientific information on this topic.

We find all of Mr Savory{\textquoteright}s major claims to be unfounded and we express deep concern that they have the potential to undermine proven, practical approaches to rangeland management and restoration that are supported by a global community of practitioners and scientists. The two major assumptions underlying Mr Savory{\textquoteright}s presentation are alone sufficient grounds for extreme skepticism. First is that humans have misunderstood the basic grassland{\textendash}grazer relationships for centuries and that only he knows the true nature of this relationship. Second is that use of intensive, concentrated livestock grazing, specific to the method that Mr Savory developed, is the only viable solution to reverse desertification and climate change. In addition to challenging these two highly problematic assumptions, we present a spe-cific critique of three invalid arguments that Mr Savory used to claim that his grazing method can reverse desertification, climate change, and alleviate human suffering and death (19:00 in video).

}, keywords = {climate change, desertification, planned grazing}, doi = {10.2111/RANGELANDS-D-13-00044.1}, url = {/files/bibliography/13-034.pdf}, author = {D.D. Briske and Brandon T Bestelmeyer and Joel R. Brown and S. Fuhlendorf and Polley, H. Wayne} } @inbook {JRN52666, title = {Cross-site comparisons of precipitation and surface water chemistry}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {46-50}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {6}, address = {Springfield, Virginia}, abstract = {

Measurements of pools and fluxes of transport or cycling of elements and compounds through the biotic and abiotic components provide critical information about the function of ecosystems. Because the time for a molecule to be completely transported through an ecosystem may be decades to millennia, long-term data provide one of the few means to estimate how ecosystems use and respond to changes in inputs of nutrients and toxic substances. This chapter tests two hypotheses related to patterns in biogeochemistry across sites: (1) patterns in atmospheric deposition over the past 20 years are different for the eastern and western parts of the U.S., and (2) changes in atmospheric deposition are related to changes in human population density for some sites. Long-term data, collected at multiple sites across the US, in chemical measurements in wet deposition, e.g., sulfur dioxide, nitrogen oxide, and ammonia emission data, and in human population size support both hypotheses.\  The results illustrate that the effects of human activities on biogeochemistry vary regionally and across the continent, and demonstrate that cross-site comparisons of long-term data can provide new insights into the spatial patterns of transport and cycling of elements and compounds.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-6.pdf}, author = {Charles T. Driscoll and Peter M. Groffman and John M Blair and Ariel E. Lugo and C. Laney and Debra C. Peters} } @article {49848, title = {Temperature drives the continental-scale distribution of key microbes in topsoil communities}, journal = {Science}, volume = {340}, year = {2013}, pages = {1574-1577}, abstract = {

Global warming will likely force terrestrial plant and animal species to migrate toward cooler areas or sustain range losses; whether this is also true for microorganisms remains unknown. Through continental-scale compositional surveys of soil crust microbial communities across arid North America, we observed a latitudinal replacement in dominance between two key topsoil cyanobacteria that was driven largely by temperature. The responses to temperature of enrichment cultures and cultivated strains support this contention, with one cyanobacterium (Microcoleus vaginatus) being more psychrotolerant and less thermotolerant than the other (M. steenstrupii). In view of our data and regional climate predictions, the latter cyanobacterium may replace the former in much of the studied area within the next few decades, with unknown ecological consequences for soil fertility and erodibility.

}, keywords = {arid North America, climate change, cyanobacteria, global warming, microbial communities, soil erosion, soil fertility}, doi = {10.1126/science.1236404}, url = {files/bibliography/JRN49848.pdf}, author = {Ferran Garcia-Pichel and Loza, Virginia and Marusenko, Yevgeniy and Mateo, Pilar and Potrafka, Ruth M.} } @inbook {JRN52673, title = {Management and policy implications of cross-and within-site, long-term studies}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {206-215}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {15}, address = {Springfield, Virginia}, abstract = {

This chapter explains the implications long-term data bring to natural resource management and policy-making.\  It first explains the two perspectives of long-term data, then explains the values brought by the two perspectives to natural resource management.\  The two perspectives are retrospective and predictive:\  long-term data enable us to examine data retrospectively to identify temporal and spatial sensitivities, and to build these historical perspectives into predictive models where we can objectively evaluate potential future scenarios. The values are as follows.\  First, with the understandings gained by retrospectively examining the long-term data, the managers can develop data-based guidelines to direct the appropriate timing and application of management practices.\  Second, long term data provide the opportunity to evaluate policies and programs that have been implemented for resource conservation.\  The ability to evaluate environmental responses following policy implementation provides the data necessary to validate policies or may lead to their subsequent revision.\  Third, long term data collection provides the opportunity for clients, partners, and stakeholders to be engaged in scientific processes. These interactions create opportunities, not only for technology and information transfers, but for users to inform the science and its research directions.\  Fourth, the predictive models built based on long-term data can be used to estimate the effects of a variety of climatic and management scenarios and are critical to informed decision-making and effective communication between natural resource managers and policy makers.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-15.pdf}, author = {Kris Havstad and Joel R. Brown} } @inbook {JRN52665, title = {Patterns of net primary production across sites}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {42-45}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {5}, address = {Springfield, Virginia}, abstract = {

Net primary production (NPP) is a fundamentally important and commonly measured ecosystem process that provides an integrative estimate of energy capture and flow into systems, and consequently the energy available for use by other trophic levels. A wide range of productivity levels occurs globally with high temporal dynamics among sites. This chapter discusses approaches to estimating NPP, highlights site-specific trends in productivity, and provides examples of past synthetic analyses across space and time. In terrestrial ecosystems, aboveground NPP are commonly measured or estimated. In many sites, spatial variation in NPP among locations within a site can overwhelm temporal variation.\  In terms temporal patterns, at some sites clear temporal trends exist: NPP either increases or decreases with time; at other sites, strong interannual variations exist.\  Past synthetic analyses have provided key insights into the relative roles of biotic versus abiotic drivers of dynamics as well as elucidating where and when biogeochemical versus climatic factors underlie patterns of NPP across biomes.\  The chapter proposes four questions that can be addressed as long-term data sets at more sites become available.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-5.pdf}, author = {A. K. Knapp and M. D. Smith and Debra C. Peters and S.L. Collins} } @inbook {JRN52663, title = {History and organization of the EcoTrends project}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {21-27}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {2}, address = {Springfield, Virginia}, abstract = {

This chapter describes the internal organization and timeline of the EcoTrends Project, from which the data and recommendations in the subsequent chapters are generated.\  The project began in 2004, and its organizational structure expanded over the next six years to include many activities and dozens of individuals from six major groups.\  The six major groups are the EcoTrends Project Office, the EcoTrends Editorial Committee, the EcoTrends Technical Committee, participating site scientists, information managers, and technical staff, the Long Term Ecological Research Network Office, and the EcoTrends Socioeconomic Working Group.\  The major activities occurred from 2004 to 2010, when this book is completed, are listed in the chapter.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-2.pdf}, author = {C. Laney and Debra C. Peters and Baker, K. S.} } @inbook {JRN52674, title = {Recommendations for data accessibility}, year = {2013}, pages = {216-225}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {16}, address = {Springfield, Virginia}, abstract = {

The EcoTrends project has generated hundreds of standardized, documented datasets from many sites and scientific fields.\  During the process of generating data comparable between many sites and across several organizational networks, novel solutions to technical, organizational, and communication challenges have been created.\  This chapter presents ten recommendations for site-level information management and for future synthesis projects.\  The recommendations are related to three broad categories: (1) data management and products, (2) project design, and (3) information environments to support synthesis projects. For each recommendation, the chapter provides specific examples of the challenges that EcoTrends faced, the lessons learned, and then explains the recommendation that may help address the challenge in future projects.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-16.pdf}, author = {C. Laney and Baker, K. S. and Debra C. Peters and Ken Ramsey} } @article {49855, title = {Plant responses, climate pivot points, and trade-offs in water-limited ecosystems}, journal = {Ecosphere}, volume = {4}, year = {2013}, abstract = {

Plant species in dryland ecosystems are limited by water availability and may be vulnerable to increases in aridity. Methods are needed to monitor and assess the rate of change in plant abundance and composition in relation to climate, understand the potential for degradation in dryland ecosystems, and forecast future changes in plant species assemblages. I employ nearly a century of vegetation monitoring data from three North American deserts to demonstrate an approach to determine plant species responses to climate and critical points over a range of climatic conditions at which plant species shift from increases to decreases in abundance (climate pivot points). I assess these metrics from a site to regional scale and highlight how these indicators of plant performance can be modified by the physical and biotic environment. For example, shrubs were more responsive to drought and high temperatures on shallow soils with limited capacity to store water and fine-textured soils with slow percolation rates, whereas perennial grasses were more responsive to precipitation in sparse shrublands than in relatively dense grasslands and shrublands, where competition for water is likely more intense. The responses and associated climate pivot points of plant species aligned with their lifespan and structural characteristics, and the relationship between responses and climate pivot points provides evidence of the trade-off between the capacity of a plant species to increase in abundance when water is available and its drought resistance.

}, keywords = {arid, Chihuahuan Desert, climate change, Colorado Plateau, cross-site, desertification, early warning sign, long-term monitoring, plant canopy cover, Sonoran Desert}, doi = {10.1890/ES13-00132.1}, url = {files/bibliography/JRN00612.pdf}, author = {Seth M. Munson} } @article {49856, title = {Regional signatures of plant response to drought and elevated temperature across a desert ecosystem}, journal = {Ecology}, volume = {94}, year = {2013}, month = {09/2013}, pages = {2030-2041}, chapter = {2030}, abstract = {

The performance of many desert plant species in North America may decline with the warmer and drier conditions predicted by climate change models, thereby accelerating land degradation and reducing ecosystem productivity. We paired repeat measurements of plant canopy cover with climate at multiple sites across the Chihuahuan Desert over the last century to determine which plant species and functional types may be the most sensitive to climate change. We found that the dominant perennial grass, Bouteloua eriopoda, and species richness had nonlinear responses to summer precipitation, decreasing more in dry summers than increasing with wet summers. Dominant shrub species responded differently to the seasonality of precipitation and drought, but winter precipitation best explained changes in the cover of woody vegetation in upland grasslands and may contribute to woody-plant encroachment that is widespread throughout the southwestern United States and northern Mexico. Temperature explained additional variability of changes in cover of dominant and subdominant plant species. Using a novel empirically based approach we identified {\textquoteleft}{\textquoteleft}climate pivot points{\textquoteright}{\textquoteright} that were indicative of shifts from increasing to decreasing plant cover over a range of climatic conditions. Reductions in cover of annual and several perennial plant species, in addition to declines in species richness below the long-term summer precipitation mean across plant communities, indicate a decrease in the productivity for all but the most drought-tolerant perennial grasses and shrubs in the Chihuahuan Desert. Overall, our regional synthesis of long-term data provides a robust foundation for forecasting future shifts in the composition and structure of plant assemblages in the largest North American warm desert.

}, keywords = {Chihuahuan Desert, climate change, climate pivot point, desertification, forecasting plant community composition, land degradation, long-term vegetation dynamics, plant canopy cover, species richness}, doi = {10.1890/12-1586.1}, url = {/files/bibliography/13-027.pdf}, author = {Seth M. Munson and E. Muldavin and Jayne Belnap and Debra C. Peters and John P. Anderson and M. Hildegard Reiser and Gallo, Kirsten and Melgoza-Castillo, Alicia and Jeffrey E. Herrick and Christiansen, Tim A.} } @inbook {JRN52664, title = {Cross-site comparisons of state-change dynamics}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {36-41}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {4}, address = {Springfield, Virginia}, abstract = {

Changes in the state of a system, for example from grasslands to shrublands or from dominance by one fish species to another species, with associated changes in other parts of the system, are often irreversible. Most of these state changes bring forth negative impacts on ecosystem, resulting in altered levels of biodiversity, rates of nutrient cycling, changes in air and water quality, and increased losses of soil and nutrients by wind and water erosion.\  This chapter illustrated six examples of state changes in various types of ecosystems: vegetation state changes in deserts, penguin dynamics in Antarctica, fish dynamics in Wisconsin lakes, plankton dynamics in the Pacific Ocean, subtidal dynamics off Pacific Coast, and shifts in coastal fish assemblages in the Pacific Ocean.\  These examples clearly show the impact of global environmental change (warming, invasive species, altered trophic structure) on the abundance and distribution of dominant and subordinate species in aquatic, marine, and terrestrial systems. Because this era of rapid environmental change is only beginning to be manifest in species responses, long-term data will continue to be needed to quantify and predict the non-linear system responses that are likely to occur in the future.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-4.pdf}, author = {Debra C. Peters and William R. Fraser and T. K. Kratz and Mark D. Ohman and Andrew Rassweiler and Sally J. Holbrook and Russell J. Schmitt} } @inbook {JRN52667, title = {Disturbance regimes and ecological responses across sites}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {58-71}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {9}, address = {Springfield, Virginia}, abstract = {

Disturbances affect ecosystems in almost limitless ways. The effects of disturbances extend beyond the initial impacts that are usually visible to the human eye. Therefore, for many disturbances long-term data are needed to unravel their effects.\  This chapter first presents characteristics of disturbances for each of four major classes of disturbance: climatic, physical, biotic, and anthropogenic.\  It then discusses ecosystem responses by disturbance class.\  For climatic disturbances, ecosystem responses to hurricanes, drought, and global warming are discussed; for physical disturbances, wildfire on land and wave height in ocean; for biotic disturbance, herbivores feeding on lower tropic levels, invasive species, and a plant disease; for anthropogenic disturbance, changes in land use patterns.\  These long-term records of ecosystem responses to disturbance illustrate the complexity of disturbance effects. Ecosystem responses are influenced by multiple disturbances and interactions with other factors, which make it very difficult to attribute cause and effect. Clearly large-scale, multiple-site experiments are needed to further unravel the relationships between particular disturbance events and ecosystem responses.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-9.pdf}, author = {Debra C. Peters and Ariel E. Lugo and F.S. Chapin III and Tepley, A. J. and F. J. Swanson} } @inbook {JRN52675, title = {Long-term research across sites, ecosystems, and disciplines: synthesis and research needs}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {226-233}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {17}, address = {Springfield, Virginia}, abstract = {

The EcoTrends Project is one of the first attempts to standardize, simplify, integrate, and visualize data from diverse terrestrial, aquatic, and marine ecosystems to promote understanding and synthesis by a broad audience. This chapter discusses key scientific results from this project, describes developing conceptual and operational frameworks for cross-site synthesis, and provides recommendations for future research. Key results are: mean air temperature has increased at 24 sites, and annual precipitation has increased at 9 sites with no obvious spatial distribution in either climate variable. Trends in atmospheric chemistry show clear patterns across the continent with reduced deposition of nitrate and sulfate in precipitation through time in the eastern U.S. compared with the West. Patterns in stream water chemistry across sites do not reflect broad-scale patterns in atmospheric chemistry; thus local conditions have strong influences on chemical inputs to and losses from streams. Human population density has increased at all sites, although at different rates. Biotic data are often idiosyncratic in that they reflect high spatial and temporal variability inherent in biological phenomenon.\  It is proposed that cross-site synthesis studies should integrate three aspects of ecological research: depth (individual sites being studied in great detail), length (data being collected over long periods), and breadth (phenomena being studied across broad spatial extents).\  The strongest recommendation for future research is to make data and associated metadata easily accessible to and usable by others.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-17.pdf}, author = {Debra C. Peters} } @inbook {JRN52669, title = {Long-term trends in climate and climate-related drivers}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {81-114}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {11}, address = {Springfield, Virginia}, abstract = {

This chapter shows long-term data and trends in climate and climate-related drivers for each site.\  It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for different variables.\  On land, air temperature (mean, minimum, and maximum), precipitation, Palmer Drought Severity Index, and Walter-Lieth climate diagrams are selected.\  In water, streamflow, sea level, ice duration, water clarity, and water temperature are selected.\  Two types of graphs are included to show trends in the variables and to provide a sense of change across a range of spatial scales (continent, site) for each variable: maps at continental scale showing either the mean across years or the slope of the regression line (if significant) across time, and site-scale data through time.\  Air temperatures are increasing in at least one variable (minimum, mean, maximum) for 27 of the 50 sites.\  Sea level is increasing at all 11 coastal sites.\  Observing these trends in climate across multiple ecosystems across continents is only possible with spatially extensive, long-term data collection and analysis, such as provided by the EcoTrends Project.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-11.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman} } @book {JRN52662, title = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {378}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, address = {Springfield, Virginia}, abstract = {

The Eco Trends Editorial Committee sorted through vast amounts of historical and ongoing data from 50 ecological sites in the continental United States including Alaska, several islands, and Antarctica to present in a logical format the variables commonly collected.\  This report presents a subset of data and variables from these sites and illustrates through detailed examples the value of comparing long-term data from different ecosystem types. This work provides cross-site comparisons of ecological responses to global change drivers, as well as long-term trends in global change drivers and responses at site and continetal scales.\  Site descriptions and detailed data also are provided in the appendix sections.

\⇒ This book is available for download (PDF format) below

\⇒ Available from http://www.ars.usda.gov/is/np/indexpubs.html

\⇒ Copies may be purchased in various formats (microfiche, photocopy, CD, print on demand) from the National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161, 800-553-6847, www.ntis.gov

Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change\  (download PDF - 313 MB)

Download the book in PDF in it\&$\#$39;s entirety (above) or by section (below)

Contents

Introduction to Cross-Site Comparisons and History and Organization of the EcoTrends Project\  (8.29 MB)

Cross-Site Comparisons of Ecological Responses to Global Change Drivers\  (21.8 MB)


Long-Term Trends in Global Change Drivers and Responses at Site and Continental Scales\  (197 MB)


Appendices \& Index\  (79 MB)

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029 Bk.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman and R. B. Waide and Jin Yao} } @inbook {JRN52676, title = {Long-term trends in ecological systems: An introduction to cross-site comparisons and relevance to global change studies}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {1-20}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {1}, address = {Springfield, Virginia}, abstract = {

This chapter explains the importance of long-term data to ecological studies and the needs of creating a way to provide accessible and comparable multi-site long-term data. The Earth{\textquoteright}s environment is changing in many ways at local, regional, and global scales. Dramatic changes have occurred in climate, land cover, and habitat availability over the past several centuries. Long-term data (\> 10 years) are needed to assess the rate and direction of change, to distinguish directional trends in these changes (e.g., persistent increases or decreases) from short-term variability (e.g., multi-year cycles), and to forecast environmental conditions in the future.\  It also sets up the stage for the rest of the chapters in the book, presenting the purposes, audience and practical applications of the book, explaining how the study sites, variables, and data sets are selected, and how the data are presented and analyzed, and laying out the organization of the book.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-1.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman and R. B. Waide and Jin Yao} } @inbook {JRN52671, title = {Long-term trends in human demography and economy across sites}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {162-190}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {13}, address = {Springfield, Virginia}, abstract = {

This chapter shows long-term data and trends in human demography and economy for each site.\  It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for different variables.\  Total population, the percentage of the population living in urban areas, and the density of people in the counties associated with each site are selected.\  Four economic variables fore each focal county of a site are also selected: the percentage of the population employed by one of four economic sectors: commercial industries, farming, manufacturing, and service industries.\  Two types of graphs are included to show change through time across a range of spatial scale for each variable: maps of continental scale showing either the \% change in total population for four time periods (1800 to 1850; 1850 to 1900, 1900 to 1950, 1950 to 2000) or the \% of the population that was urban in each of four time periods (1850, 1900, 1950, 2000); and maps and graphs showing site-scale data through time. The settlement of the country occurred from the east coast and then to the west coast by 1900, and then to the interior between 1900 and 1950. Losses of population in the Midwest occurred between 1950 and 2000. Most areas of the country had a high percentage of urban population by 1950. Urbanization continued for most of the country until 2000 with the Northeast, Appalachian Mountains, and northern Wisconsin providing notable exceptions.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-13.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman} } @inbook {JRN52670, title = {Long-term trends in precipitation and surface water chemistry}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {115-161}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {12}, address = {Springfield, Virginia}, abstract = {

This chapter shows long-term data and trends in precipitation and surface water chemistry for each site.\  It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for different variables.\  Volume-weighted concentration (mg/L) and area-based wet deposition (kg/ha) from precipitation, and concentration in surface water (mg/L) of nitrogen (as nitrate and ammonium), sulfur (as sulfate), chloride, and calcium are selected.\  Two types of graphs are included to show trends in the variables and to provide a sense of change across a range of spatial scales (continent, site) for each variable: maps at continental scale showing either the mean across years or the slope of the regression line (if significant) across time, and site-scale data through time.\  Nitrate and sulfate deposition are decreasing in many Eastern sites, consistent with efforts to control emissions of acid-causing nitrogen and sulfur from power plants in this part of the country.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-12.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman} } @inbook {JRN52672, title = {Long-term trends in production, abundance, and richness of plants and animals}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {191-205}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {14}, address = {Springfield, Virginia}, abstract = {

This chapter shows long-term data and trends in production, abundance, and richness of plants and animals for each site.\  It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for different variables.\  Net primary production, plant biomass and species richness, animal abundance and species richness are selected.\  Figure of site-scale data through time of each variable is shown, and a regression line is shown if the relationship is significant and the trend appears linear.\  The site graphs are shown on a continental map with similar sites to allow comparison among sites.\  At many sites, multiple locations are sampled for plant and animal dynamics. The large within-site variability in responses often overwhelms trends through time.\  Although plant response variables of ANPP, richness, and biomass are sampled for most sites to allow cross-site comparisons, animal response variables are more variable among sites with fewer comparable groups. These results indicate that each site selects representative trophic groups from the local ecosystems, instead of attempting to standardize across sites.\  The length of the time series also varies across sites which further complicates cross-site comparisons.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-14.pdf}, author = {Debra C. Peters and C. Laney and Ariel E. Lugo and S.L. Collins and Charles T. Driscoll and Peter M. Groffman and Grove, J. Morgan and A. K. Knapp and T. K. Kratz and Mark D. Ohman} } @article {49860, title = {Ecosystem resilience despite large-scale altered hydroclimatic conditions}, journal = {Nature}, volume = {494}, year = {2013}, month = {2013}, pages = {349-352}, chapter = {349}, abstract = {

Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological model for many regions1. Largescale, warm droughts have recently occurred in North America, Africa, Europe, Amazonia and Australia, resulting in major effects on terrestrial ecosystems, carbon balance and food security2,3. Here we compare the functional response of above-ground net primary production to contrasting hydroclimatic periods in the late twentieth century (1975{\textendash}1998), and drier, warmer conditions in the early twenty-first century (2000{\textendash}2009) in the Northern and Southern Hemispheres. We find a common ecosystem water-use efficiency (WUEe: above-ground net primary production/evapotranspiration) across biomes ranging from grassland to forest that indicates an intrinsic system sensitivity to water availability across rainfall regimes, regardless of hydroclimatic conditions. We found higher WUEe in drier years that increased significantly with drought to a maximum WUEe across all biomes; and a minimum native state in wetter years that was common across hydroclimatic periods. This indicates biome-scale resilience to the interannual variability associated with the early twenty-first century drought{\textemdash}that is, the capacity to tolerate low, annual precipitation and to respond to subsequent periods of favourable water balance. These findings provide a conceptual model of ecosystem properties at the decadal scale applicable to the widespread altered hydroclimatic conditions that are predicted for later this century. Understanding the hydroclimatic threshold that will break down ecosystem resilience and alter maximum WUEe may allow us to predict land-surface consequences as large regions become more arid, starting with waterlimited, low-productivity grasslands.

}, keywords = {aboveground net primary production, air temperature, ANPP, climate change, drought, ecosystem resilience, evapotranspiration, hydroclimate, MODIS, plant production, precipitation}, doi = {10.1038/nature11836}, url = {/files/bibliography/13-022.pdf}, author = {Guillermo E. Ponce-Campos and S. Moran and Alfredo Huete and Yongguang Zhang and Bresloff, Cynthia and T. Huxman and Eamus, Derek and David D. Bosch and Anthony R. Buda and Stacey A. Gunter and Scalley, Tamara Heartsill and S.G. Kitchen and M.P. McClaran and McNab, W. Henry and Montoya, Diane S. and Jack A. Morgan and Debra C. Peters and John Sadler and M. S. Seyfried and Paul F. Starrs} } @article {JRN54874, title = {Acequias and the Effects of Climate Change}, year = {2013}, abstract = {

Traditional forms of acequia irrigation can be combined with ground based and remote sensing snow measurements and snowmelt runoff modeling to better estimate runoff volumes now and in the future under conditions of climate change. The experience gained over 400 years of irrigating small fields strongly binds communities and strengthens the resolve of acequia associations to contest challenges presented by climate change. Increased density of snow measurements in high elevations of the Rio Grande along with input of real-time data to snowmelt models has led to an improved potential for acequia decision making under the increased temperatures projected for the future by climate models. Acequia communities and similar Native American settlements have shown the willingness to share water during times of severe water shortages in the southwestern U.S. Acequia associations have shown the desire to adopt new forms of hydrologic data and modeling techniques and incorporate them into acequia association approaches.

}, keywords = {Acequias, climate change, snowmelt runoff modeling}, doi = {10.1111/j.1936-704X.2013.03154.x}, url = {/files/bibliography/13-042.pdf}, author = {A. Rango and Alexander Fernald and Caitriana Steele and Hurd, B. and Carlos Ochoa} } @article {49863, title = {Earth Stewardship of rangelands: coping with ecological, economic, and political marginality}, journal = {Frontiers in Ecology and the Environment}, volume = {11}, year = {2013}, month = {09/2013}, pages = {348-354}, chapter = {348}, abstract = {

Rangelands encompass 30\–40\% of Earth\’s land surface and support 1 to 2 billion people. Their predominant use is extensive livestock production by pastoralists and ranchers. But rangelands are characterized by ecological, economic, and political marginality, and higher value, more intensive land uses are impinging on rangelands around the world. Earth Stewardship of rangelands must address both livestock management and the broader socioecological dynamics that promote land-use changes, fragmentation, and degradation. We identify specific gradients on which human\–rangeland systems can be arrayed, including issues of variability, adaptation to disturbance, commercialization, land-use change, land-tenure security, and effective governance, and we illustrate the gradients\’ interactions and effects in sites worldwide. The result is a synthetic framework to help in understanding how rangeland Earth Stewardship can be achieved in the face of marginality, globalization, and climate change.

}, keywords = {climate change, Earth Stewardship, globalization, marginality, rangeland management, socioecological dynamics}, doi = {10.1890/120333}, url = {/files/bibliography/13-025.pdf}, author = {N. F. Sayre and McAllister, Ryan R. J. and Brandon T Bestelmeyer and Moritz, Mark and M.G. Turner} } @article {49866, title = {Runoff responses to long-term rainfall variability in a shrub-dominated catchment}, journal = {Journal of Arid Environments}, volume = {91}, year = {2013}, month = {01/2013}, pages = {88-94}, chapter = {88}, abstract = {In this study we investigate how rainfall has changed between two nine year periods (1977-1985 and 2003-2011), and evaluate the effects of changes in rainfall on runoff from a shrub-dominated catchment in the southwestern USA. Analysis of rainfall characteristics shows that between these two periods there is an overall increase in annual rainfall, which corresponds with a long-term increase in rainfall in this region. Analysis of the frequency-magnitude distribution of rainfall events during these two periods indicates that there has not been a significant change in the return period of daily rainfall totals, whereas there has been a significant change in the return period of runoff-generating rainfall events. Between the two periods, there has been a large increase in the return period for a runoff event of a given magnitude. Although there has been an increase in rainfall between the two periods, results show that, contrary to
what might be expected, an overall increase in rainfall has not resulted in an increase in runoff because of a change in the frequency-magnitude distribution of runoff-generating rainfall events. We anticipate that this reduction in runoff is due to a reduction in rainfall intensities between the two periods.\  \© 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jaridenv.2012.12.002}, keywords = {climate change, frequency, magnitude, rainfall, runoff response, Tromble Weir}, doi = {10.1016/j.jaridenv.2012.12.002}, url = {/files/bibliography/13-004.pdf}, author = {Turnbull, L. and A.J. Parsons and John Wainwright and John P. Anderson} } @inbook {JRN52668, title = {Cross-site studies "by design:" Experiments and observations that provide new insights}, booktitle = {Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change}, year = {2013}, pages = {72-80}, publisher = {National Technical Information Services}, organization = {National Technical Information Services}, chapter = {10}, address = {Springfield, Virginia}, abstract = {

The cross-site comparisons presented in the previous chapters are all conducted after the individual studies are completed.\  The differences in experimental design in individual studies in a posteriori cross-site studies limit the scope of questions that can be addressed, and the powerfulness and confidence in the conclusions.\  This chapter describes cross-site studies that are {\textquotedblleft}by design{\textquotedblright} where the questions, experimental layout, methods, and measurements included multiple sites from the beginning. These a priori cross-site studies provide powerful tools to understand the phenomenon of global change and to predict its impacts on ecosystems and society. Two types of a priori cross-site studies are described: (1) experimental manipulations of drivers or system properties, and (2) observations or monitoring of natural or managed ecosystems located along environmental gradients. Within each type, examples of both on-going or completed experiments and new or developing experiments are presented.\  For each example, insights that would not have been obtained with other approaches are also presented. The limitations and difficulties of this type of studies are listed.

}, keywords = {atmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry}, url = {/files/bibliography/13-029-10.pdf}, author = {Jin Yao and O. E. Sala and Debra C. Peters} } @article {49878, title = {A synthetic review of feedbacks and drivers of shrub encroachment in arid grasslands}, journal = {Ecohydrology}, volume = {5}, year = {2012}, month = {10/2012}, pages = {520-530}, chapter = {520}, abstract = {Many arid grasslands around the world are affected by woody plant encroachment and the replacement of a relatively continuous grass cover with shrub patches bordered by bare soil. This shift in plant community composition is often abrupt in space and time, suggesting that it is likely sustained by positive feedbacks between vegetation and environmental conditions (e.g., resource availability) or disturbance regime (e.g., fire or freeze). These feedbacks amplify the effects of drivers of shrub encroachment, i.e., of conditions favoring a shift from grass to shrub dominance (e.g., overgrazing, climate change). Here we review some major drivers and feedbacks and identify the basic stages in the transition from grassland to shrubland. We discuss some possible scenarios of interactions between drivers and feedbacks that could explain the transition from a stage to the next, and the potential irreversibility of the shift from grass to shrub dominance. We introduce a simplistic modeling framework that can integrate the various drivers to explain the emergence of bistability for shrub-encroached grassland systems.}, keywords = {climate change, fire ecology, shrub encroachment, soil erosion, sptial dynamics}, doi = {10.1002/eco.259}, url = {/files/bibliography/12-024.pdf}, author = {Paolo D{\textquoteright}Odorico and Gregory S. Okin and Brandon T Bestelmeyer} } @article {49912, title = {Banded vegetation-dune development during the Medieval Warm Period and 20th century, Chihuahuan Desert, New Mexico, USA}, journal = {Ecosphere}, volume = {3}, year = {2012}, month = {03/2012}, pages = {art21}, chapter = {art21}, abstract = {

With the advent of systematic high-resolution satellite photography, striking geometric shapes of banded vegetation several km2 in size, but not apparent from the ground, have been documented for many areas of the arid and semiarid world. Banded vegetation, in which dense perennial vegetation alternates with bands of bare soil may originate from geomorphic processes, ecological self-organization, or human land use. In the Chihuahuan Desert of New Mexico prominent arc-shaped bands of vegetation and dunes occur along the contact of a piedmont slope (bajada) and basin floor. The origin and chronology of this banded vegetation-dune complex was investigated using early aerial photography (1936{\textendash}1942), landscape photography (1918), vegetation and soil surveys (1858, 1918), soil stratigraphy, 13C/12C ratios, and 14C dating. These methods reveal two periods of eolian deposition. The first began in the Medieval Warm Period (ca. AD 900{\textendash}1300) and was followed by a period of landscape stability during the Little Ice Age (ca. AD 1500 to 1850). The second began in the late-1800s when widespread desertification occurred throughout the American Southwest. Banded vegetation was initiated after formation of erosional scarplets that functioned as obstacles upon which eolian sand accumulated, thus becoming a dam to overland flow and causing strips of vegetation to form. Banded vegetation in this study is an emergent pattern produced by a coupled ecologic-geomorphic-climatic system. The stratigraphic record produced by this system enables us to compare current ecological responses to climate change with baseline prehistorical responses to climate change.

}, keywords = {carbon isotopes, climate change, desert geomorphology, emergence, Little Ice Age, Medieval Warm Period, object-based image analysis, positive feedback mechanisms, soil radiocarbon dating}, doi = {10.1890/ES11-00194.1}, url = {/files/bibliography/12-010.pdf}, author = {Weems, Stacey L. and Curtis H. Monger} } @article {49944, title = {The ecology of dust}, journal = {Frontiers in Ecology and the Environment}, volume = {8}, year = {2011}, pages = {423-430}, abstract = {Wind erosion and associated dust emissions play a fundamental role in many ecological processes and provide important biogeochemical connectivity at scales ranging from individual plants up to the entire globe. Yet, most ecological studies do not explicitly consider dust-driven processes, perhaps because most relevant research on aeolian (wind-driven) processes has been presented in a geosciences rather than an ecological context. To bridge this disciplinary gap, we provide a general overview of the ecological importance of dust, examine complex interactions between wind erosion and ecosystem dynamics from the scale of plants and surrounding space to regional and global scales, and highlight specific examples of how disturbance affects these interactions and their consequences. It is likely that changes in climate and intensification of land use will lead to increased dust production from many drylands. To address these issues, environmental scientists, land managers, and policy makers need to consider wind erosion and dust emissions more explicitly in resource management decisions.}, keywords = {aeolian processes, biogeochemistry, climate change, disturbance, drylands, dust, dust emissions, dust flux, ecological processes, ecosystem dynamics, land use, resource management, wind erosion}, doi = {10.1890/090050}, author = {J. P. Field and Jayne Belnap and David D. Breshears and J. Neff and Gregory S. Okin and J. J. Whicker and Painter, T. H. and S. Ravi and Reheis, M. C. and Reynolds, R. L.} } @article {49965, title = {Responses of wind erosion to climate-induced vegetation changes on the Colorado Plateau}, journal = {Proceedings of the National Academy of Sciences}, volume = {108}, year = {2011}, pages = {3854-3859}, abstract = {

Projected increases in aridity throughout the southwestern United States due to anthropogenic climate change will likely cause reductions in perennial vegetation cover, which leaves soil surfaces exposed to erosion. Accelerated rates of dust emission from wind erosion have large implications for ecosystems and human wellbeing, yet there is poor understanding of the sources and magnitude of dust emission in a hotter and drier climate. Here we use a two-stage approach to compare the susceptibility of grasslands and three different shrublands to wind erosion on the Colorado Plateau and demonstrate how climate can indirectly moderate the magnitude of aeolian sediment flux through different responses of dominant plants in these communities. First, using results from 20 y of vegetation monitoring, we found perennial grass cover in grasslands declined with increasing mean annual temperature in the previous year, whereas shrub cover in shrublands either showed no change or declined as temperature increased, depending on the species. Second, we used these vegetation monitoring results and measurements of soil stability as inputs into a field-validated wind erosion model and found that declines in perennial vegetation cover coupled with disturbance to biological soil crust resulted in an exponential increase in modeled aeolian sediment flux. Thus the effects of increased temperature on perennial plant cover and the correlation of declining plant cover with increased aeolian flux strongly suggest that sustained drought conditions across the southwest will accelerate the likelihood of dust production in the future on disturbed soil surfaces.

}, keywords = {arid, climate change, Colorado Plateau, horizontal flux, land use, national park, threshold shear velocity, vegetation change, wind erosion}, doi = {10.1073/pnas.1014947108}, url = {files/bibliography/JRN00582.pdf}, author = {Seth M. Munson and Jayne Belnap and Gregory S. Okin} } @article {50021, title = {Spatial and temporal variability of plant-available water in calcium carbonate-cemented soils and consequences for arid ecosystem resilience}, journal = {Oecologia}, volume = {163}, year = {2010}, note = {August 14, 2008-Ecology; resubmitted to Oecologia 3-19-2009 w/new title}, pages = {215-226}, chapter = {215}, abstract = {

Increased variability in precipitation, including frequency of drought, is predicted for many arid and semiarid regions of the world. The ability of soils to retain water can increase resilience by buffering vegetation communities against precipitation extremes. Little is known, however, about water retention by carbonate cemented soil horizons, which occur extensively in arid and semiarid ecosystems. It has been speculated that they may significantly modify vertical and temporal distribution of plant-available water (PAW). To investigate this hypothesis, PAW was monitored at three sites in a mixed shrub-grass community in southern New Mexico, USA, across soils with differing degrees of carbonate horizon development: no carbonate horizon, a partially cemented calcic horizon, and a continuously cemented petrocalcic horizon. Results are presented from three years that included extremely dry and wet periods. Calcic and petrocalcic horizons absorbed and retained significantly greater amounts of PAW for several months following an extremely wet winter and summer compared to the non-carbonate soil. Following a wet summer, petrocalcic horizons retained very high PAW (16 to 18\% volumetric or ~72 to 80\% of soil water holding capacity) through early spring of the following year, more than double the PAW retained by similar depths in the non-carbonate soil. Drying dynamics indicate calcic and petrocalcic horizons release stored water into the grass rooting zone during growing seasons following extreme events. Water dynamics of calcic and petrocalcic horizons during extreme events provide a mechanism to explain previous observations that perennial grasses exhibit greater resilience to drought when high carbonate horizons occur at shallow depths (\< 50 cm). Water holding capacity of the entire profile, including rock-like material such as calcium carbonate, should be considered when evaluating the potential resilience of vegetation communities to disturbance, including the increased variability in precipitation expected to occur as a result of global climate change.

}, keywords = {calcic, Chihuahuan Desert, climate change, desert grassland, ecosystem, horizon, Petrocalcic, precipitation}, doi = {10.1007/s00442-009-1530-7}, url = {/files/bibliography/10-03.pdf}, author = {Danielle Duni and Jeffrey E. Herrick and Curtis H. Monger} } @article {50123, title = {Scale and the isotopic reocrd of C4 plants in pedogenic carbonate: from the biome to the rhizosphere}, journal = {Ecology}, volume = {90}, number = {6}, year = {2009}, note = {//USDA,OTHER//LTER V//entered 07/13/2009; pdf available}, month = {2009}, pages = {1498-1511}, abstract = {The 13C/12C ratio in pedogenic carbonate (i.e., CaCO3 formed in soil) is a significant tool for investigating C4 biomes of the past. However, the paleoecological meaningof d13C values in pedogenic carbonate can change with the scale at which one considers the data. We describe studies of modern soils, fossil soils, and vegetation change in the Chihuahuan Desert of North America and elsewhere that reveal four scales important for paleoecologic interpretations. (1) At the broadest scale, the biome scale (hundreds to millions of km2), an isotopic record interpreted as C3 vegetation replacing C4 grasslands may indicate invading C3 woody shrubs instead of expanding C3 forests (a common interpretation). (2) At the landscape scale (several tens of m2 to hundreds of km2), the accuracy of scaling up paleoclimatic interpretations to a regional level is affected by the landform containing the isotopic record. (3) At the soil-profile scale (cm2 to m2), soil profiles with multiple generations of carbonate mixed together have a lower-resolution paleoecologic record than soil profiles repeatedly buried. (4) At the rhizosphere scale (lm2 to cm2), carbonate formed on roots lack the 14{\textendash}17{\o} enrichment observed at broader scales, revealing different fractionation processes at different scales. A multi-scale approach in dealing with d13C in pedogenic carbonate will increase the accuracy of paleoecologic interpretations and understanding of soil{\textendash}geomorphic{\textendash}climatic interactions that affect boundaries between C4 and C3 vegetation.}, keywords = {article, C3 vs C4 vegetation, carbon isotopes, Chihuahuan Desert, climate change, desertification, Jornada Experimental Range, journal, landscape ecology, pedogenic carbonate, peleoclimate, peleoecology, soil-geomorphic-clmatic interaction, southern New Mexico, USA}, author = {Curtis H. Monger and David R. Cole and B. J. Buck and R. A. Gallegos} } @article {50159, title = {Climate change and ecoystems of Asia with emphasis on Inner Mongolia and Mongolia}, journal = {Rangelands}, volume = {30}, number = {3}, year = {2008}, month = {06/01/2008}, pages = {46-51}, abstract = {Asia is the most populated continent with almost 3.9 billion people. More than half of these people live in rural areas, with many as pastoralists depending on livestock and rangelands for their livelihood. Rangelands occupy over 4.3 b ac (1.72 b ha) on the Asian continent, almost 38\% of the total land area. For some counties, such as Sri Lanka and Laos in southeast Asia, the percentage of rangeland within their borders is relatively minor. However, for many Asian nations rangelands are a major land category. Countries such as China, Mongolia and Russia in northern Asia, and Iran, Afghanistan and Turkey in western Asia (more commonly referred to as the Middle East) have huge expanses of grasslands and shrublands, and more than 40\% of the land in these nations is categorized as rangeland. Given these extent and diversity of rangelands across this continent, this paper will focus on an area central to the continent that is still extremely important as a pastoral landscape. The region of Mongolia and Inner Mongolia, China (boxed area within Fig. 1) represents nearly 1.3 b ac (520 m ha) of rangeland, about 30\% of the rangeland area across this continent. In both Mongolia and Inner Mongolia, livestock production on rangelands is a major source of wealth and well being. Due to large contiguous land areas of rangelands in this region, impacts to the rangeland resource from changing climate would make livestock producers especially vulnerable. In this paper, we will provide an overview of the existing status and uses of rangelands in Mongolia and Inner Mongolia, the projected impacts of climate change, and a discussion on future strategies that can be employed to adaptively manage and reduce vulnerability in this changing environment.}, keywords = {Asia, climate change, Mongolia, rangelands}, url = {/files/bibliography/08-017.pdf}, author = {Angerer, J. and G. Han and Fujisaki, I. and Kris Havstad} } @article {50174, title = {Climate change and rangelands: Responding rationally to uncertainty}, journal = {Rangelands}, volume = {30}, number = {3}, year = {2008}, month = {June 30, 2008}, pages = {3-6}, abstract = {Rangelands constitute a substantial portion of the earth{\textquoteright}s surface and contribute a wide variety of products and services to human well being. Global climate change will have an inordinate impact on rangelands because the productivity of grass and shrub dominated ecosystems is so closely linked to the short term expression of climate, weather. In general, most rangeland ecosystems and human activities associated with them are forecast to experience increasingly erratic precipitation and temperature patterns in the short and mid term future (20-100 years). Other aspects of global change, such as CO2 fertilization, invasive species and changes in land use, will also have significant effects on the ability of rangelands to meet human needs and desires.}, keywords = {climate change, rangelands}, url = {/files/bibliography/08-020.pdf}, author = {Joel R. Brown and Thorpe, J.} } @article {50176, title = {Rangelands and climate change: A synthesis and challenges}, journal = {Rangelands}, volume = {30}, number = {3}, year = {2008}, month = {June 30, 2008}, pages = {52-53}, abstract = {

Climate change, along with other aspects of global change, represents a great challenge to rangeland management in the coming century. Coping with this challenge requires collaboration among scientists, managers and policy makers to develop new tools and management systems. This collaboration should focus on meeting the need for 1) improved prediction of changes in climate and the subsequent effects on rangeland ecosystems at relevant spatial scales, 2) integrated monitoring systems and 3) the necessity of managers to respond with unprecedented speed and flexibility to changes in their operating environment.

}, keywords = {climate change, rangelands}, doi = {10.2111/1551-501X(2008)30[52:RACCAS]2.0.CO;2}, url = {/files/bibliography/08-021.pdf}, author = {Joel R. Brown and Thorpe, J.} } @mastersthesis {50188, title = {Bioclimatic changes recorded in Holocene soils at the Jornada Basin LTER site and Lincoln National Forest, southern New Mexico}, year = {2008}, note = {//USDA//LTER V//entered 06/11/2009; abstract added 06/22/2009ProCite field[12]: Not in File (06/11/2009)}, month = {2008}, pages = {67}, school = {New Mexico State University}, type = {M.S. Thesis}, address = {Las Cruces, NM}, abstract = {In order to understand the impact humans are having on desertification, it is necessary to address the magnitude of natural cycles of climate change and how it drives the migration of dryland biomes. Paleoclimate studies are useful for obtaining information about natural cycles of climate-driven vegetation change. This paleoclimate study uses carbon isotopes (13C/12C) in Holocene soils to derive paleoclimate information about the movement of arid, semiarid, and subhumid bioclimatic boundaries along an elevational transect in southern NM. Soil profiles of limestone alluvium at four sites of increasing rainfall and decreasing temperature were analyzed for their stable carbon values in order to make inferences about bioclimatic changes (C3 versus C4 vegetation) during the Holocene. This paleoclimate record suggests that the arid site was dominated by C3 shrub vegetation for the last 4,000 years, the semiarid site by C4 grasslands for approximately the last 3,000 yrs, and the subhumid A site by C3 trees or C3 cool season grasses for the last 7,000 yrs. However, minor shifts in the relative proportions of C3 versus C4 vegetation did occur during these time periods. The implications of these findings are that there were no major changes in vegetation (biome movement) during the last 4,000 to 7,000 years this time period. Within each bioclimatic zone vegetation was similar to today\&$\#$39;s vegetation. Still, subtle changes in the isotopic record may reflect the climatic influences of the Medieval Warm Period and Little Ice Age.}, keywords = {bioclimate, carbon isotope ratios, climate change, dissertation, Jornada Basin, Lincoln National Forest, soils, Holocene, thesis}, url = {NMSU Branson Library call $\#$: S 1999 .C88 2008 c.2}, author = {Cruz, Janella} } @article {50192, title = {Contributing to the mitigation of climate change using rangeland management}, journal = {Rangelands}, volume = {30}, number = {3}, year = {2008}, month = {06/2008}, pages = {7-11}, abstract = {

The mitigation of climate change through rangeland management based projects seems to be viable in the marketplace. Carbon sequestration via rangeland management has a sound basis in both economics and ecology if the offset projects are compatible with existing land uses and management systems. However, to be competitive in a global, multisectoral market, rangeland projects must operate efficiently within market prices and rules and exploit inherent competitive advantages. Rangeland carbon sequestration projects are competitive because of the relatively low cost of achieving increased soil carbon storage and compatibility with existing management operations and production systems. Documenting and verifying changes in carbon storage may be a difficult challenge. The success of rangeland projects as participants in a private sector market will be determined in large part by the ability of the rangeland management profession (scientists, advisors and managers) to develop accurate, credible and cost-effective protocols to insure that gains are real.

}, keywords = {climate change, mitigation, rangeland management}, url = {/files/bibliography/08-019.pdf}, author = {DeSteiguer, J.E. and Joel R. Brown and Thorpe, J.} } @article {50230, title = {Shrub encroachment in North American grasslands: Shifts in growth form dominance rapidly alters control of ecosystem carbon inputs}, journal = {Global Change Biology}, volume = {14}, year = {2008}, month = {January 30, 2008}, pages = {615-623}, publisher = {Blackwell Publishing}, abstract = {

Shrub encroachment into grass-dominated biomes is occurring globally due to a variety of anthropogenic activities, but the consequences for carbon (C) inputs, storage and cycling remain unclear. We studied eight North American graminoid-dominated ecosystems invaded by shrubs, from arctic tundra to Atlantic coastal dunes, to quantify patterns and controls of C inputs via aboveground net primary production (ANPP). Across a 4-fold range in mean annual precipitation (MAP), a key regulator of ecosystem C input at the continental scale, shrub invasion decreased ANPP in xeric sites, but dramatically increased ANPP (\>1000 g/m2) at high MAP, where shrub patches maintained extraordinarily high leaf area. Concurrently, the relationship between MAP and ANPP shifted from being non-linear in grasslands to linear in shrublands. Thus, relatively abrupt (\<50 yrs) shifts in growth form dominance, without changes in resource quantity, can fundamentally alter continental-scale pattern of C inputs and control by MAP in ways that exceed the direct effects of climate change alone.

}, keywords = {aboveground net primary production, carbon, climate change, encroachment, grass-dominated biomes, grasslands, growth form, LAI, MAP, North American, shrub, shrublands}, doi = {10.1111/j.1365-2486.2007.01512.x }, url = {/files/bibliography/08-005.pdf}, author = {A. K. Knapp and J. M. Briggs and S.L. Collins and Steven R. Archer and M.S. Bret-Harte and Ewers, B. and Debra C. Peters and Young, D. and Shaver, G. and Cleary, M.B.} } @proceedings {50263, title = {Predicitons for snow cover, glaciers and runoff in a changing climate}, year = {2008}, month = {09/2008}, pages = {277-280}, address = {Prague, Czech Republic}, abstract = {

The problem of evaluating the hydrological effects of climate change has opened a new field of applications for snowmelt runoff models. The Snowmelt Runoff Model (SRM) has been used to evaluate climate change effects on basins in North America, the Swiss Alps, and the Himalayas. Snow covered area depletes about one month earlier in response to warmer temperatures (+40C) with runoff peaks shifted accordingly. Runoff will be higher in winter at the expense of summer runoff. In glacerized basins, runoff is not only redistributed, but increased due to glacier melting. This improved knowledge facilitates long-term decisions concerning hydropower, flooding, water allocations, and water management in general.

}, keywords = {climate change, proceedings, runoff, snowmelt, SRM}, url = {/files/bibliography/08-038.pdf}, author = {A. Rango and J. Martinec} } @conference {50265, title = {Predictions for snow cover, glaciers and runoff in a changing climate}, booktitle = {Hydrology and Water Resrouces International Conference Proceedings}, year = {2008}, abstract = {The problem of evaluating the hydrological effects of climate change has opened a new field of applications for snowmelt runoff models. The Snowmelt Runoff Model (SRM) has been used to evaluate climate change effects on basins in North America, the Swiss Alps, and the Himalayas. Snow covered area depletes about one month earlier in response to warmer temperatures (+4oC) with runoff peaks shifted accordingly. Runoff will be higher in winter at the expense of summer runoff. In glacerized basins, runoff is not only redistributed, but increased due to glacier melting. This improved knowledge facilitates long-term decisions concerning hydropower, flooding, water allocations, and water management in general.}, keywords = {climate change, hydrology, runoff shifts, snowmelt runoff modelling, water management}, author = {A. Rango and J. Martinec} } @inbook {50278, title = {Land resources: forests and arid lands}, booktitle = {The effects of climate change on agriculture, land resources, water resources, and biodiversity in the United States.}, series = {Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research}, number = {Synthesis and Assessment Product 4.3.}, year = {2008}, note = {//USDA//LTER V//entered 05/29/2008; PDF availableProCite field[6]: InProCite field[8]: Convening lead authorsProCite field[31]: Managing editor}, month = {2008}, pages = {362 pp.}, address = {Washington, DC., USA}, abstract = {

This synthesis and assessment report builds on an extensive scientific literature and series of recent assessments of the historical and potential impacts of climate change and climate variability on managed and unmanaged ecosystems and their constituent biota and processes. It identifies changes in resource conditions that are now being observed and examines whether these changes can be attributed in whole or part to climate change. It also highlights changes in resource conditions that recent scientific studies suggest are most likely to occur in response to climate change, and when and where to look for these changes. As outlined in the Climate Change Science Program (CCSP) Synthesis and Assessment Product 4.3 (SAP 4.3) prospectus, this chapter will specifically address climate-related issues in forests and arid lands.In this chapter the focus is on the near-term future. In some cases, key results are reported out to 100 years to provide a larger context but the emphasis is on next 25-50 years. This nearer-term focus is chosen for two reasons. First, for many natural resources, planning and management activities already address these time scales through development of long-lived infrastructure, forest rotations, and other significant investments. Second, climate projections are relatively certain over the next few decades. Emission scenarios for the next few decades do not diverge from each other significantly because of the {\textquotedblleft}inertia{\textquotedblright} of the energy system. Most projections of greenhouse gas emissions assume that it will take decades to make major changes in the energy infrastructure, and only begin to diverge rapidly after several decades have passed (30-50 years).

}, keywords = {arid lands, book, chapter, climate change, desertification, report}, url = {files/bibliography/JRN00504.pdf}, author = {Ryan, M. G. and Steven R. Archer and Birdsey, R. and Dahm, C. and Heath, L. and Hicke, J. and Hollinger, D. and T. Huxman and Gregory S. Okin and Oren, R. and J. Randerson and W. H. Schlesinger}, editor = {Backlund, Peter and Janetos, Anthony and David Schimel} } @conference {50287, title = {Multiple constraints on ecological restoration: Re-establishment of black grama grass (Bouteloua eriopoda) after intensive grazing}, booktitle = {Ecological Society of America Abstracts}, series = {93rd ESA Annual Meetings}, year = {2008}, month = {August 4-8, 2008}, pages = {COS 119-7}, address = {Milwaukee, WI}, abstract = {Climate change may alter potential ecological restoration of semi-arid rangeland. Bouteloua eriopoda (black grama, BOER) is a perennial C4 grass that usually fails to re-establish in degraded rangeland and may be constrained by increased atmospheric CO2 and reduced or seasonally redistributed rainfall. Eighteen contiguous 0.5-ha plots were established in a remnant black grama grassland at the Jornada Experimental Range in the Northern Chihuahuan Desert. Removal of mesquite shrubs (Prosopis glandulosa) and intensive seasonal grazing (none, winter, summer) were applied in a randomized complete block design. From 1996-2000 annual grazing removed 65-85\% of the available forage in 24-36 h, a grazing intensity 30X greater than in the previous 40 years. In 2002 the mean percent cover of BOER was 5.82{\textpm}0.94 in grazed plots compared to 27.3{\textpm}1.33 in ungrazed plots. By 2005 BOER had not re-established. A pair of circular 1 m diameter, 6.35 mm wire mesh exclosures, were randomly located in each of the 18 plots. Annually from 2005-2007 the treatment exclosure of each pair had non-BOER above-ground biomass removed and viable BOER seed planted and fertilized.}, keywords = {abstract, climate change, restoration}, author = {S. Tartowski and D. K. James} } @article {50434, title = {Effects of altered temperature and precipitation on desert protozoa associated with biological soil crusts}, journal = {Journal of Eukaryotic Microbiology}, volume = {53}, number = {6}, year = {2006}, note = {//USDA//USGS//Entered 11/21/2006}, month = {2006}, pages = {507-514}, abstract = {Biological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when associated with cyanobacteria/lichen crusts than with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert (cool desert, primarily winter precipitation) declined 50-, 10-, and 100-fold, respectively, when moved in field mesocosms to the Chihuahuan Desert (hot desert, primarily summer rain). However, this was not observed in protozoa collected from the Chihuahuan Desert and moved to the Sonoran desert (hot desert, also summer rain, but warmer than Chihuahuan Desert). Protozoa in culture began to encyst at 37 1C. Cysts survived the upper end of daily temperatures (37{\textendash}55 1C), and could be stimulated to excyst if temperatures were reduced to 15 1C or lower. Results from this study suggest that cool desert protozoa are influenced negatively by increased summer precipitation during excessive summer temperatures, and that desert protozoa may be adapted to a specific desert{\textquoteright}s temperature and precipitation regime.}, keywords = {article, Chihuahuan Desert, climate change, Colorado Plateau, cryptobiotic crust, environmental stress, journal, soil change, soil function, soil crust, biological, soil fauna, soil food webs, soil protozoa, soil, ecosystem function, soil, food web, soil, methods, thermotolerance}, isbn = {DOI: 10.1111/j.1550-7408.2006.00134.x}, author = {Darby, Brian J. and Housman, David C. and Zaki, Amr M. and Shamout, Yassein and Adl, Sina M. and Jayne Belnap and Neher, Deborah A.} } @article {50452, title = {Selected Essays on Science, Rangelands, and Roles of the Society for Range Management, Volume II}, journal = {Rangelands}, volume = {28}, year = {2006}, month = {08/2006}, pages = {35-38}, chapter = {35}, abstract = {This is a second set of essays that address topics of concern to rangeland science, and the profession of rangeland management. This set of essays primarily focuses on phenomena related to climate change. There are many recent reports where changes in climate at regional to global scales have been quantified. For example, warming during the winter months of the Earth{\textquoteright}s Antarctic troposphere has been observed at 0.5-0.7 degrees C per decade over the last 30 years. Recent studies have also documented dramatic increases in discharges of glaciers tied to polar ice sheets in both the northern and southern hemispheres. Most of these changes re presumed to be linked to present level of atmospheric carbon dioxide of 380 parts per million, up from the preindustrial level of the 19th Century of 290 ppm. The USDA, Agricultural Research Service, as well as other research programs in the western US, are addressing objectives for adapting to dynamic environments. There are a number of current research projects generating data sets related to coping with drought, contending with shifting vegetation structure and composition, plant responses to elevated atmospheric CO2 levels, and relationships of vegetation to water yields. These projects will be crucial for informing adaptation of policies and resource management in response to changing climates.}, keywords = {climate change, global scales, rangeland management, rangeland science}, doi = {10.2111/1551-501X(2006)28[35:SEOSRA]2.0.CO;2}, url = {/files/bibliography/06-043.pdf}, author = {Kris Havstad} } @conference {50718, title = {Arid ecosystem responses to variations in the frequency and magnitude of growing season precipitation}, booktitle = {89th Annual Meeting, Ecological Society of America}, year = {2004}, month = {August 1, 2004}, pages = {Abstract p. 476}, address = {Portland, OR}, abstract = {Global climate change models predict regional changes in average seasonal precipitation, but few models or experiments address how changes in the delivery of precipitation within the growing season will affect ecosystem responses. Arid systems differ from mesic systems in that water availability is frequently low enough to severely restrict biological activity. Consequently, the frequency and magnitude of precipitation events, which dictate the length and severity of intervening dry periods, may have substantial effects on ecosystem function regardless of the total amount of seasonal rainfall. We examined how a 60 mm increase in summer precipitation (46\% increase over mean summer rainfall) applied with two different frequencies and magnitudes during the growing season affected carbon, water and nitrogen dynamics of a Chihuahuan Desert scrub ecosystem. Plots containing mesquite (Prosopis glandulosa) and black grama grass (Bouteloua eriopoda) were assigned to either: ambient precipitation (controls), ambient plus frequent small (5-6 mm) rainfall events applied weekly, and ambient plus infrequent large (20-24 mm) events applied monthly. Mesquite used rainfall from 5 mm and 24 mm storms, as evidenced by increased stem elongation, improved water status and uptake of deuterium-labeled rainfall, but mesquite response was greater under large infrequent rainfalls. Daytime measurements of net ecosystem carbon exchange on subplots containing soil, plant roots and biological soil crusts indicated biological soil crust photosynthesis was improved by frequent small rainfalls. Keeling plot analyses of d13C of respired CO2 during dark hours indicated that the contribution from different sources (roots, microbes and soil crusts) varied with rainfall treatment. Both infrequent large rainfalls and frequent small rainfalls significantly increased nitrogen availability, especially in the surface soil. We found that changes in the depth and duration of soil wetting, resulting from different precipitation patterns, have important implications for ecosystem carbon and nitrogen dynamics because of the differential sensitivity of ecosystem components.}, keywords = {arid systems, climate change, ecosystem responses, growing season precipitation}, author = {K. A. Snyder and Cable, J.M. and T. Huxman and S. Tartowski} } @article {50776, title = {Extreme events as shaping physiology, ecology, and evolution of plants: toward a unified definition and evaluation of their consequences}, journal = {New Phytologist}, volume = {160}, year = {2003}, note = {//NMSU,USDA//LTER IV//}, month = {2003}, pages = {21-42}, abstract = {

The paper considers how extreme events, particularly climatic and biotic, affect the physiology, development, ecology and evolution of organisms, focusing on plants. It is proposed that extreme events need to be defined in terms of organismal responses of acclimation and of de-acclimation or hysteresis. From this a number of hypotheses are developed, including that fitness effects of extreme events occur primarily during recovery. Evidence is reviewed that selection is virtually absent except during extreme events on the evolutionary time scale. Extreme events drive strong directional selection, even to trait fixation and speciation. A number of new tools are described, both conceptual and technological, that are now at hand or that merit rapid development.

}, keywords = {acclimation, article, articles, biogeographic limits, climate change, evolution, extreme events, journal, journals, natural selection, neutrality, physiological ecology}, doi = {10.1046/j.1469-8137.2003.00866.x}, url = {files/bibliography/JRN00384.pdf}, author = {V. P. Gutschick and H. BassiriRad} } @article {JRN55000, title = {Climate change and biotic invasions: a case history of a tropical woody vine}, journal = {Biological Invasions}, volume = {5}, year = {2003}, pages = {147-165}, chapter = {147}, abstract = {

The impacts of climate change in the potential distribution and relative abundance of a C3 shrubby vine, Cryptostegia grandiflora, were investigated using the CLIMEX modelling package. Based upon its current naturalised distribution, C. grandiflora appears to occupy only a small fraction of its potential distribution in Australia under current climatic conditions; mostly in apparently sub-optimal habitat. The potential distribution of C. grandiflora is sensitive towards changes in climate and atmospheric chemistry in the expected range of this century, particularly those that result in increased temperature and water use efficiency. Climate change is likely to increase the potential distribution and abundance of the plant, further increasing the area at risk of invasion, and threatening the viability of current control strategies markedly. By identifying areas at risk of invasion, and vulnerabilities of control strategies, this analysis demonstrates the utility of climate models for providing information suitable to help formulate large-scale, long-term strategic plans for controlling biotic invasions. The effects of climate change upon the potential distribution of C. grandiflora are sufficiently great that strategic control plans for biotic invasions should routinely include their consideration. Whilst the effect of climate change upon the efficacy of introduced biological control agents remain unknown, their possible effect in the potential distribution of C. grandiflora will likely depend not only upon their effects on the population dynamics of C. grandiflora, but also on the gradient of climatic suitability adjacent to each segment of the range boundary.

}, keywords = {biological control, climate change, CLIMEX, Cryptostegia, global change, invasion, modelling, range shifts, weed}, url = {files/bibliography/03-036.pdf}, author = {Kriticos, D. J. and Sutherst, R. W. and Joel R. Brown and Adkins, S.W. and Maywald, G. F.} } @article {50926, title = {Plant species dominance at a grassland-shrubland ecotone: An individual-based gap dynamics model of herbaceous and woody species}, journal = {Ecological Modelling}, volume = {152}, number = {1}, year = {2002}, month = {June 1, 2002}, pages = {5-32}, abstract = {

Transition zones or ecotones between biomes are predicted to be particularly sensitive areas to directional changes in climate. However, for many ecotones, there is little understanding of the key processes that allow dominant species from adjacent biomes to coexist at transition zones and how differences in these processes affect species responses to changes in environmental conditions. The objective of this study was to examine the relationship between plant life history traits and patterns in dominance and composition at a grassland{\textendash}shrubland transition zone in order to predict shifts in dominance with directional changes in climate. It was hypothesized that differences in life history traits allow species from adjacent biomes to coexist at this transition zone, and that these dominance patterns are dynamic through time as a result of species-specific responses to changes in climate. A mixed lifeform individual plant-based gap dynamics model (ECOTONE) was developed to examine consequences of differences in recruitment, resource acquisition, and mortality to patterns in species dominance and composition under a variety of soils and climatic conditions. This model is unique because it represents interactions among multiple potential dominant species that include congeneric species of one lifeform as well as herbaceous and woody lifeforms across multiple spatial scales. Similar to other gap models, ECOTONE simulates the recruitment, growth, and mortality of individual plants on a small plot through time at an annual timestep. ECOTONE differs from other gap models in the degree of detail involved in determining successful recruitment by each species and in the simulation of belowground resources. Individual plant root distributions and resource availability by depth are dynamic. Soil water content is simulated on a daily timestep and nitrogen is simulated monthly. Multiple spatial scales can be simulated using a grid of plots connected by seed dispersal. ECOTONE was parameterized for two soil types at the Sevilleta National Wildlife Refuge (SEV), a site located within the transition zone between two major biomes in North America. Shortgrass steppe communities are dominated by the perennial grass Bouteloua gracilis (blue grama) and Chihuahuan desert communities are dominated by the perennial grass Bouteloua eriopoda (black grama) or the shrub Larrea tridentata (creosotebush). Experiments were conducted to provide key parameters related to recruitment and growth that were supplemented with information from the literature for remaining parameters. Model output was verified using field estimates of cover and biomass for the three dominant species as well as other groups of species. Simulation analyses were conducted under current climate and for a directional change in climate. Nitrogen was assumed constant for all runs to allow a focus on water availability constraints as affected by climate. Under current climatic conditions, simulated biomass on sandy loam soils was dominated by B. eriopoda with smaller biomass of B. gracilis and other species groups. By contrast, simulated biomass on a loamy sand soil was codominated by B. eriopoda and L. tridentata with very small biomass attributed to other species groups. Under a GFDL climate change scenario of increased year-round temperatures and increased summer precipitation, vegetation patterns shifted to a clear dominance of biomass by B. eriopoda on both soil types. These results show that temporal partitioning of soil water is important to codominance by the two Bouteloua species, and that spatial and temporal partitioning of soil water is important for grass{\textendash}shrub interactions. The results also suggest that global climate change may provide a mechanism for the recovery of B. eriopoda following shrub invasion in the Southwestern U.S. Thus, an individual-based modeling approach is capable of representing complex interactions among herbaceous and woody species as well as between congeneric species with different life history traits at a biome transition zone. This modeling approach is useful in improving our understanding of key processes driving these vegetation dynamics as well in predicting shifts in dominance as environmental conditions change in the future.

}, keywords = {Bouteloua species, Chihuahuan Desert, climate change, creosotebush, ECOTONE, shortgrass steppe}, doi = {10.1016/S0304-3800(01)00460-4}, url = {files/bibliography/JRN00362.pdf}, author = {Debra C. Peters} } @article {JRN54960, title = {Hydrological Effects of a Changed Climate in Humid and Arid Mountain Regions}, journal = {World Resource Review}, volume = {12}, year = {2000}, pages = {493508}, chapter = {493}, abstract = {

The effect of a hypothetical temperature increase of +4{\textdegree}C on snow cover and on year-round runoff is evaluated for the very humid basin Illecillewaet (1155 km2, 509-3150 m a.s.l., British Columbia, Canada), the semi-humid basin of Kings River (3999 km2, 171-4341 m a.s.l., California, USA), and the semi-arid basin of Rio Grande at Del Norte (3419 km2, 2432-4215 m a.s.l., Colorado, USA). In contrast to current methods of evaluating the climate effect, a realistic seasonal snow cover from satellite monitoring is used to represent the present climate, the non-calibrated SRM model is applied to transform this snow cover under conditions of a warmer climate to compute climate-affected runoff.

The winter snow accumulation is particularly reduced in the Kings River basin which has the greatest elevation range. In absolute terms, the smallest snowpack reduction occurred in the semi-arid basin of Rio Grande at Del Norte. The decline of snow covered area in the snowmelt season in accelerated by about one month in all basins. The runoff in the winter half year is about doubled at the expense of the summer half year in the basins Illecillewaet and Kings River. This effect is smaller in the basin Rio Grande at Del Norte. Because the climate change was limited to a temperature increase, there is no significant change in the yearly runoff volume in the basins Kings River and Rio Grande. There is a yearly runoff increase in the Illecillewaet basin due to enhanced glacier melt.

}, keywords = {climate change, glaciers, runoff, snow, water resources planning}, url = {files/bibliography/Rango2000-02.pdf}, author = {A. Rango and J. Martinec} } @article {51170, title = {Geographic patterns of simulated establishment of two Bouteloua species: Implications for distributions of dominants and ecotones}, journal = {Journal of Vegetation Science}, volume = {10}, year = {1999}, month = {1999}, pages = {343-356}, abstract = {

Our overall objective was to use a soil water model to predict spatial patterns in germination and establishment of two important perennial C4-bunchgrasses across the North American shortgrass steppe and desert grassland regions. We also predicted changes in establishment patterns under climate change scenarios. Bouteloua gracilis dominates the shortgrass steppe from northeastern Colorado to southeastern New Mexico. Bouteloua eriopoda dominates desert grasslands in central and southern New Mexico. Germination and establishment for each species were predicted at 16 sites along the gradient using a daily time step, multi-layer soil water model (SOILWAT) to determine the percentage of years that temperature and soil water criteria for germination and establishment were met. Percentage of years with predicted establishment decreased from north to south for B. gracilis, but increased from north to south for B. eriopoda, comparable to observed dominance patterns. The 95 \% confidence interval around the point at which simulated establishment were equal for the two species was near the location of the shortgrass steppe-desert grassland ecotone where both species are abundant. The intersection in percentage of years with establishment for the two species was predicted to move further north when climate was scaled using three Global Circulation Models (GCMs), indicating a possible northward expansion of B. eriopoda. Our results suggest that recruitment by seed may be an important process in determining, at least in part, the geographic distribution of these two species. Changes in climate that affect establishment constraints could result in shifts of species dominance that may or may not be accompanied by changes in species composition.

}, keywords = {Bouteloua eriopoda, Bouteloua gracilis, Chihuahuan Desert grassland, climate change, Geographic distribution, shortgrass steppe, simulation model}, doi = {10.2307/3237063}, url = {/files/bibliography/672.pdf}, author = {Minnick, T.J. and D.P. Coffin} } @article {JRN54959, title = {Modeling Snow Cover and Runoff Response to Global Warming for Varying Hydrological Years}, journal = {World Resource Review}, volume = {11}, year = {1999}, pages = {76-91}, chapter = {76}, abstract = {

The effect of future global warming on the seasonal snow cover and runoff is evaluated in the Rio Grande basin at Del Norte, Colorado for average (1976), low (1977), and high (1979) runoff years. Precipitation data are extrapolated to the respective elevations of the basin by taking into account the snow accumulation obtained from snow cover mapping by satellites. Snow covered areas are used as one of the input variable for the Snowmelt Runoff Model. In order to derive the climate-affected snow covered areas of the future, the decrease of the areal snow water equivalent on 1 April is computed and used to derive new snow cover depletion curves indicative of the accelerated snowmelt in the warmer climate. Day-by-day runoff computations using present temperatures and temperatures increased by +4{\textdegree}C reveal a short-term and seasonal redistribution of runoff which differs according to the character of the selected hydrological years. Winter runoff approximately doubles in 1976 (+ 107\%), considerably increases in 1976 (+ 60\%), and slightly rises in 1977 (+ 22\%). The summer runoff consequently declines in all years, but the seasonal runoff peaks are shifted to earlier in the spring as a result of an earlier beginning of the snowmelt season in the warmer climate.

}, keywords = {climate change, remote sensing, snow and ice hydrology, water resources planning}, url = {files/bibliography/Rango1999-01.pdf}, author = {A. Rango and Martinrc, Jaroslav} } @article {JRN54988, title = {Response of Snowmelt Hydrology to Climate Change}, journal = {Water, Air and Soil Pollution}, volume = {90}, year = {1996}, pages = {335-343}, chapter = {335}, abstract = {

In mountainous regions where the accumulation and melt of seasonal snow cover are important for runoff production, the timing and quantity of water supply could be strongly affected by regional climate change, particularly altered temperature and precipitation regimes. In this paper, the hydrological response to climate change scenarios is examined using a semi-distributed snowmelt runoff model. The model represents an improvement over simple temperature-based models, in that it incorporates the net radiation into the snowpack. Thus it takes into account the basin{\textquoteright}s topography and slope orientation when computing snowmelt. In general, a warmer climate is expected to shift snowmelt earlier into the winter and spring, decreasing summer runoff. The effects of other potential climate changes (such as precipitation and cloudiness patterns) are explored. The uncertainties in these predictions are discussed. \ 

}, keywords = {climate change, net radiation, runoff, snow cover, snowmelt, water supply}, url = {files/bibliography/Rango1996-08.pdf}, author = {K.L. Brubaker and A. Rango} }