@proceedings {JRN55372, title = {Quantifying the water quality benefits of implementing manureshed concept based manure management in the Susquehanna River Basin}, year = {2022}, month = {4/4/2022}, abstract = {The manureshed concept was developed to address the uneven distribution of manure nutrients in and around livestock operations and recycle manure in areas where crops require nutrients. The implementation of manureshed concept can improve manure nutrient use efficiency and reduce manure nutrient loss to downstream waterbodies. The study aims to quantify the water quality benefits of implementing manureshed concept for nutrient management in the Susquehanna River Basin (SRB) through scenario-based analyses using the Soil and Water Assessment Tool (SWAT). The specific objectives include (i) formulation of manureshed concept-based nutrient redistribution scenarios for the SRB, (ii) evaluation of water quality impacts of manureshed concept-based manure management in SRB both at outlet draining to the Chesapeake Bay and at local streams. Six manureshed concept-based manure redistribution scenarios were formulated for the SRB, which included (i) Crop N demand-based Restricted Manure Transport (BL, Baseline), (ii) Crop N demand-based Manure Balanced (N-MB; manure redistributed to nearby nutrient demand areas), (iii) Crop N demand-based Suitable Soil Transport (N-SST; Manure applied only in suitable areas), (iv) Crop P demand-based Restricted Manure Transport (P-RT), (v) Crop P demand-based Manure Balanced (P-MB), and (vi) Crop P demand-based Suitable Soil Transport (P-SST). Scenario-based analyses demonstrated that the crop P demand-based manure application significantly reduced manure nutrient loss; the P-MB scenario simulated 3\% TN and 25\% TP loss reductions at the SRB outlet compared to the BL scenario. The crop N demand-based manure application simulated a 3-5\% reduction in nutrient loading at the watershed outlet compared to baseline; the N-SST scenario simulated 3\% TN and 4\% TP loss reductions at the SRB outlet. The study results are promising and encourage stakeholders to implement manureshed concept-based manure management in SRB.}, keywords = {concept based manure management, implementing, manureshed, Susquehanna River Basin, water quality}, author = {Amartya Saha and Gourab Saha and Raj Cibin and S. Spiegal and Peter J. A. Kleinman and Tamie L. Veith and Charles M. White and Patrick. J. Drohan} } @article {JRN55325, title = {Quadrat-based monitoring of desert grassland vegetation at the Jornada Experimental Range, New Mexico, 1915-2016}, year = {2021}, abstract = {The data set covers a 101-year period (1915{\textendash}2016) of quadrat-based plant sampling at the Jornada Experimental Range in southern New Mexico. At each sampling event, a pantograph was used to record the location and perimeter of living plants within permanent quadrats. Basal area was recorded for perennial grass species, canopy cover area was recorded for shrub species, and all other perennial species were recorded as point data. The data set includes 122 1 m by 1 m permanent quadrats, although not all quadrats were sampled in each year of the study and there is a gap in monitoring from 1980{\textendash}1995. These data provide a unique opportunity to investigate changes in the plant community over 100 years of variation in precipitation and other environmental conditions. We provide the following data and data formats: (1) the digitized maps in shapefile format; (2) data table containing coordinates (x,y) of perennial species within quadrats, including cover area for grasses and shrubs; (3) data table of counts of annual plant individuals per quadrat; (4) species list indicating growth form and habit of recorded species; (5) table of dates when each quadrat was sampled; (6) table of the pasture each quadrat was located within (note that pasture boundaries have changed over time); (7) table of depth to petrocalcic layer measurements taken at quadrat locations; (8) table of particle size analysis of soil samples taken at quadrat locations; (9) table of topographic characteristics of quadrat locations (e.g. concave or convex topography). Pantograph sampling is currently conducted at 5 year intervals by USDA-ARS staff, and new data will be added periodically to the EDI Data Portal Repository (see section V.E.2). This information is released under the Creative Commons license - Attribution - CC BY and the consumer of these data is required to cite it appropriately in any publication that results from its use.}, keywords = {arid grasslands, Chihuahuan Desert, long-term research, New Mexico, particle size analysis, plant community, plant populations, quadrat, rangeland, soil texture}, doi = {10.1002/ecy.3530}, url = {files/bibliography/21-041.pdf}, author = {Erica M. Christensen and D. K. James and A. L. Slaughter and Connie J. Maxwell and Peter B. Adler and Kris Havstad and Brandon T Bestelmeyer} } @article {JRN54800, title = {Quantifying long-term trajectories of plant community change with movement models: implication for ecological resilience}, journal = {Ecological Applications}, volume = {27}, year = {2017}, month = {07/2017}, pages = {1514-1528}, chapter = {1514}, abstract = {

Quantification of rates and patterns of community dynamics is central for understanding the organization and function of ecosystems. These insights may support a greater empirical understanding of ecological resilience, and the application of resilience concepts toward ecosystem management. Distinct types of dynamics in natural communities can be used to interpret and apply resilience concepts, but quantitative methods that can systematically distinguish among them are needed. We develop a quantitative method to analyze long-term records of plant community dynamics using principles of movement ecology. We analyzed dissimilarity of species composition through time with linear and nonlinear statistical models to assign community change to four classes of movement trajectories. Compositional change in each sampled plot through time was classified into four classes, stability, abrupt nonlinear change, transient reversible change, and gradual linear drift, each representing a different aspect of ecological resilience. These competing models were evaluated based on estimated coefficients, goodness of fit, and parsimony. We tested our method{\textquoteright}s accuracy and robustness through simulations, or the ability to distinguish among trajectories and classify them correctly. We simulated 16,000 trajectories of four types, of which 94{\textendash}100\% were correctly classified. Next, we analyzed 13 long-term vegetation records from North American grasslands (annual grasslands with warm-season and cool-season communities, shortgrass, mixed grass, and tallgrass prairies, and sagebrush steppe), and a record of primary succession at Mt. St. Helens volcano. Collectively, we analyzed 14,647 observations from 775 plots, between 1915 and 2012. Dynamics could be reliably assigned for 705 plots (91\%), and overall statistical fit was high (goodness of fit, 0.77 {\textpm} 0.15 SD). Among the perennial grasslands, stability was most common (44\% of all plots), followed by gradual linear (22\%), abrupt nonlinear (17\%), and reversible (6\%) change. Among annual grasslands, abrupt nonlinear shifts (33\%) were more common in the warm-season community than in the cool-season (20\%). As expected, abrupt nonlinear change was common during primary succession (51\%) while reversible change was rare (3\%). Generally, reversible dynamics often required 2{\textendash}3 decades. Analysis of long-term community change, or trajectories, with principles of movement ecology provides a quantitative basis to compare and interpret ecological resilience within and among ecosystems.

}, keywords = {long-term monitoring, model selection, multiple equilibria, nonlinear regression, parsimony, resilience indicators, Time series, tipping points vegetation change}, doi = {10.1002/eap.1544}, url = {files/bibliography/17-019.pdf}, author = {Bagchi, Sumanta and Singh, Navinder and D.D. Briske and Brandon T Bestelmeyer and M.P. McClaran and Murthy, Karthik} } @article {JRN54390, title = {Quantifying soil and critical zone variability in a forested catchment through digital soil mapping}, journal = {Soil}, volume = {1}, year = {2015}, month = {01/2015}, pages = {47-64}, chapter = {47}, abstract = {

Quantifying catchment scale soil property variation yields insights into critical zone evolution and function. The objective of this study was to quantify and predict the spatial distribution of soil properties within a high elevation\  forested catchment in southern AZ, USA using a combined set of digital soil mapping (DSM) and sampling design techniques to quantify catchment scale soil spatial variability. The study focused on a 6 ha catchment on granitic parent materials under mixed-conifer forest, with a mean elevation of 2400ma.s.l., mean annual temperature of 10 C and mean annual precipitation of 85 cmyr-1. The sample design was developed using a unique combination of iterative principal component analysis (iPCA) of environmental covariates derived from remotely sensed imagery and topography, and a conditioned Latin Hypercube Sampling (cLHS) scheme. Samples were collected by genetic horizon from 24 soil profiles excavated to the depth of refusal and characterized for soil mineral assemblage, geochemical composition, and general soil physical and chemical properties. Soil properties were extrapolated across the entire catchment using a combination of least squares linear regression between soil properties and selected environmental covariates, and spatial interpolation or regression residual using inverse distance weighting (IDW). Model results indicated that convergent portions of the landscape contained deeper soils, higher clay and carbon content, and greater Na mass loss relative to adjacent slopes and divergent ridgelines. The results of this study\  indicated that: (i) the coupled application of iPCA and cLHS produced a sampling scheme that captured the majority of catchment scale soil variability; (ii) application of relatively simple regression models and IDW interpolation of residuals described well the variance in measured soil properties and predicted spatial correlation of soil properties to landscape structure; and (iii) at this scale of observation, 6 ha catchment, topographic covariates explained more variation in soil properties than vegetation covariates. The DSM techniques applied here provide a framework for interpreting catchment scale variation in critical zone process and evolution. Future work will focus on coupling results from this coupled empirical-statistical approach to output from mechanistic, process-based numerical models of critical process and evolution.

}, doi = {10.5194/soil-1-47-2015}, url = {/files/bibliography/15-019.pdf}, author = {Holleran, M. and Matthew Levi and Craig Rasmussen} } @conference {JRN54407, title = {On quantifying active soil carbon using mid-infrared spectroscopy}, booktitle = {5th International Symosium on Soil Organic Matter Dynamics: Land USe, Management and Global Change}, year = {2015}, month = {09/2015}, address = {Gottingen, Germany}, abstract = {

Soil organic matter (SOM) is derived from plant or animal residues deposited on or in soil and is in various stages of decomposition and mineralization.\  Total SOM is a common measure of soil quality, although due to its heterogeneous composition SOM can vary dramatically in terms of its biochemical properties and residence times, which ultimately affects soil heath and function.\ \ \  One operationally defined SOM fraction is {\textquotedblleft}active soil carbon{\textquotedblright} (ASC) which is thought to consist of readily oxidizable SOM that is responsive to management practices and may provide one measure of {\textquotedblleft}soil health{\textquotedblright} closely associated with soil biological activity.\  ASC can be a useful indicator to assist farmers and land managers in their selection of soil management practices to maintain ASC or to build total SOM.\  ASC has generally been measured using permangate oxidation, a costly and time-intensive procedure.\  Chemometric modeling using mid-infrared spectroscopy (MIR) has been successfully used to estimate a range of soil properties, including total organic carbon (TOC) and particulate organic carbon (POC).\  Consequently, we hypothesized that we could use MIR to estimate ASC.\  Here we report on a method that uses MIR and chemometric signal processing to quantify TOC and ASC on a variety of soils collected serially and seasonally from 76 locations across the United States.\  TOC was measured using high temperature oxidation and ASC was measured as permanganate-oxidizable carbon.\  These data were used to calibrate and validate MIR-based partial least squares (PLS) regression models that were used to estimate TOC and ASC using MIR alone.\  Signal processing included 1st or 2nd derivatives of the spectra with various gaps in the data and continuum removal.\  We used a goodness of fit statistic (R2) and the lowest root mean square error of prediction (RMSEP) to select the most robust models.\  The best predictive model for TOC was built on spectral data following continuum removal with 9 components, and had an R2 of 0.95 and RMSEP of 0.18.\  For ASC, the model was built on a 1st derivative of the spectral data with a gap of 8, and had an R2 of 0.86 and RMSEP of 0.22.\  We conclude that ASC can be reasonably estimated with MIR.\  When combined simultaneously to estimate ASC and other soil properties (e.g., TOC, POC), MIR becomes a cost effective means of characterizing large numbers of samples and could easily provide repeatable measures of the status and condition of\  soil carbon due to land management practices.\  Our presentation will describe the details of developing these models and the utility of ASC as one metric for quantifying {\textquotedblleft}soil health{\textquotedblright}.

}, author = {Jonathan Maynard and Mark Johnson} } @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 {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} } @proceedings {JRN54042, title = {Quantifying accelerated soil erosion through ecological site-based assessments of wind and water erosion}, year = {2014}, month = {07/2014}, pages = {p. 357}, publisher = {International Society of Aeolian Research (ISAR)}, address = {Lanzhou, China}, abstract = {

This work explores how organising soil erosion assessments using established groupings of similar soils (ecological sites) can inform systems for managing accelerated soil erosion. We evaluated aeolian sediment transport and fluvial erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Our results show that sediment transport and erosion can be highly variable within and among ecological sites. Plots in shrub-encroached and shrub-dominated states were consistently susceptible to both aeolian sediment transport and fluvial erosion. However, grassland plots and plots with a grass-succulent mix had a high indicated susceptibility to wind and water erosion respectively. Vegetation thresholds for controlling erosion are identified that transcend the ecological sites and their respective states. The thresholds define vegetation cover levels at which rapid (exponential) increases in sediment transport and erosion rates begin to occur, suggesting that erosion in the study ecosystem can be effectively controlled when bare ground cover is \<20\% of a site or total ground cover is \>50\%. Similarly, our results show that erosion can be controlled when the cover of canopy interspaces \>50 cm in length reaches ~50\%, the cover of canopy interspaces \>100 cm in length reaches ~35\% or the cover of canopy interspaces \>150 cm in length reaches ~20\%. This process-based understanding can be applied, along with knowledge of the differential sensitivity of vegetation states, to improve erosion management systems. Land use and management activities that alter cover levels such that they cross thresholds, and/or drive vegetation state changes, may increase the susceptibility of sites to erosion. Land use impacts that are constrained within the natural variability of sites should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds and natural variability of ecological sites will enable improved identification of where and when accelerated soil erosion occurs and the development of practical management solutions.

}, author = {Nicholas Webb and Jeffrey E. Herrick and Danielle Duni} } @conference {50027, title = {Quantifying terpenes in rumen fluid, serum, and plasma from sheep}, booktitle = {Journal of Animal Science}, volume = {88}, year = {2010}, pages = {58}, abstract = {Determining the fate of terpenes consumed by browsing ruminants require methods to quantify their presence in blood and rumen fluid. Our objective was to modify an existing procedure for plasma terpenes to quantify 25 structurally diverse mono- and sesquiterpenes in serum, plasma, and rumen fluid from sheep. The terpenes examined were tricyclene, α-pinene, camphene, sabinene, β-pinene, myrcene, 2-carene, 3-carene, α-terpinene, p-cymene, limonene, 1,8-cineole, cis-β-ocimene, γ-terpinene, cis-sabinene hydrate, terpinolene, linalool, camphor, borneol, terpin-4-ol, α-terpineol, longifolene, β-caryophyllene, α-humulene, and caryophyllene oxide. Terpenes were extracted with SPE columns and quantified using gas chromatography (n = 8 per terpene/fluid combination). Data were analyzed with the MIXED procedure of SAS with fluid as the independent factor, and means were separated by LSD in the event of a significant F test (α = 0.05). Recovery estimates were 100{\textpm} 5\% for 14, 7, and 4 terpenes from serum, plasma, and rumen fluid, respectively. Recovery from plasma and serum differed for 12 terpenes (P < 0.05), although typically differences were <10\%. Recovery from rumen fluid differed (P < 0.05) from both serum and plasma for 16 compounds (lower in each case except linalool). Recovery did not differ (P > 0.05) among the 3 matrices for only 2 compounds (p-cymene and terpinolene). Greater recovery was generally observed for oxygenated terpenes than hydrocarbon compounds, particularly for monoterpenes. This procedure is applicable to a wide array of terpenes in fluids from sheep, but differential recoveries among terpenes and fluids require that estimated concentrations of each analyte be corrected for recovery using that specific compound in the same matrix collected under the same set of experimental conditions, and that caution be exercised in generalizing responses among different compounds with this procedure.}, keywords = {daily gain, mesquite, steers}, url = {/files/bibliography/10-011.pdf}, author = {Richard E. Estell and S. A. Utsumi and Andr{\'e}s F. Cibils} } @article {50356, title = {Quantitative effects of vegetation cover on wind erosion and soil nutrient loss in a desert grassland of southern New Mexico, USA}, journal = {Biogeochemistry}, volume = {85}, year = {2007}, note = {//USDA//LTER-V//entered 08/14/2007}, month = {2007}, pages = {317-332}, abstract = {

Wind is a key abiotic factor that influences the dynamics of arid and semiarid systems. We investigated two basic relationships on vegetation manipulation (grass cover reduction) plots at the Jornada Experimental Range in southern New Mexico: (1) wind erosion rates (horizontal mass flux and dust emission) versus vegetative cover, and (2) nutrient loss versus vegetative cover. The results indicate that wind erosion rates and nutrient loss by dust emission are strongly affected by plant cover; however, the importance of shrubs and grasses in reducing dust flux may not be equal. The dramatic increase of wind erosion between 75\% grass cover reduction and 100\% grass cover reduction suggests that sparsely distributed mesquites are relatively ineffective at reducing wind erosion and nutrient loss compared to grasses. Comparisons of nutrients between surface soils and wind blown dust indicate that aeolian transport is a major cause for the loss of soil nutrients in susceptible environments. We found that increased aeolian flux over three windy seasons (March 2004{\textendash}July 2006) removed up to 25\% of total organic carbon (TOC) and total nitrogen (TN) from the top 5 cm of soil, and about 60\% of TOC and TN loss occurred in the first windy season (March{\textendash}July 2004). The balance between net loss of nutrients by aeolian processes and the addition of nutrients by biotic processes changed from negative (net loss) to positive (net accumulation) between 50\% grass cover reduction and 25\% grass cover reduction. The estimated lifetime of surface soil TOC and TN of about 10 years on the plot with 100\% grass cover reduction indicates that impacts of wind erosion on soil resources can occur on very short timescales.

}, keywords = {aeolian processes, aeolian processes, desertification, article, deserts, journal, soil carbon, soil nitrogen, soil nutrients, carbon, soil nutrients, nitrogen, vegetation change, nutrient loss, vegetation change, wind erosion, vegetation cover, wind erosion, windblown sediment}, doi = {10.1007/s10533-007-9142-y}, url = {files/bibliography/JRN00480.pdf}, author = {Junran Li and Gregory S. Okin and Lorelei Alvarez and Howard Epstein} } @conference {50911, title = {Quantifying changes in carbon pools accompanying shrub invasion of a desert grassland}, booktitle = {17th Annual Symposium, International Association for Landscape Ecology}, year = {2002}, month = {April 23, 2002}, pages = {110}, address = {Lincoln, NE}, abstract = {Coincident with a worldwide increase in the abundance of woody plants within former grasslands, desert grasslands through the southwestern U.S. have experienced a substantial increase in the abundance of shrubs during the last century. These changes in grassland structure have had important implications for ecosystem carbon cycling and rates of carbon sequestration. Building on a history of biogeochemistry research conducted at the Jornada Experimental Range in southern New Mexico, we measured and modeled above and below-ground carbon storage in black grama grasslands (Bouteloua eriopoda) and mesquite (Prosopis glandulosa) and creosotebush (Larrea tridentata) shrublands across the Jornada basin. Our research approach combined direct field measurement of carbon pools, extensive use of existing Jornada datasets and simulation modeling using the CENTURY model in an effort to scale field-based measurements to landscape-level estimates of carbon pools. Our results refute the commonly held thesis that carbon storage shifts from below to aboveground with shrub invasion of grasslands, but overall net ecosystem carbon remains the same. Landscape-level mapped estimates of carbon pools indicate that the desert grassland ecosystem of the Jornada basin may have served as a carbon sink during the last century.}, author = {K. A. Mitchell and Debra C. Peters and Curtis H. Monger and Jeffrey E. Herrick} } @article {51147, title = {A qualitative geophysical explanation for "hot spot" dust emitting source regions}, journal = {Contributions to Atmospheric Physics}, year = {1999}, note = {//??//LTER III// Record added 01/25/2000}, month = {1999}, keywords = {article, articles, dust sources, eolian processes, journal, journals}, author = {D. E. Gillette} } @article {51458, title = {Quantitative modeling of soil forming processes in deserts: the CALDEP and CALGYP models}, year = {1994}, note = {//NMSU//LTER III//ProCite field[6]: In}, month = {1994}, pages = {129-145}, institution = {Soil Science Society of America}, address = {Madison, Wisconsin}, abstract = {

Many models have been developed to simulate CaC03 (calcite) formation in soils. Mechanistic models that focus primarily on the long-term formation of CaC03 are summarized in Table 8-1. These models differ with respect to: (i) the mechanism of CaC03 formation, (ii) Ca sources, (iii) the inclusion of chemical kinetics, (iv) spatial and temporal variability in pH and CO2, (v) the type of rainfall model, and (vi) the inclusion of other minerals in the model.

}, keywords = {book, books, calcite, also SEE , calcite, formation model, calcium carbonate, also SEE , chapter, chapters, gypsum, formation model, model, calcite formation, model, CALDEP, model, CALGYP, report, reports, soil chemistry, soil, paleo-processes}, isbn = {SSSA Special Publication 39}, url = {files/bibliography/JRN00178.pdf}, author = {G. M. Marion and W. H. Schlesinger} } @proceedings {52207, title = {Quaternary stratigraphy in the Basin and Range and Great Plains provinces, New Mexico and western Texas}, year = {1976}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1976}, publisher = {Dowden, Hutchinson and Ross}, abstract = {The primary objective of this paper is to discuss the present status of Quaternary stratigraphy in the Mexican Highland section of the Basin and Range physiographic province, and the Pecos Valley and southern High Plains sections of the Great Plains province. Sequences in adjacent areas of southern Arizona and Colorado are also briefly discussed as are relations of some associated units of pre-Quaternary age. Particular attention is give to the geomorphic settings of these units, the development of present drainage, and the interaction between alluvial processes, tectonism, and volcanism in closed and open basin systems. Author responsibility is as follows: north-central New Mexico -- Manley; central New Mexico and Pecos Valley -- Bachman; and southern New Mexico and western Texas -- Hawley. Detailed field are in progress or have been recently completed by the authors in these areas and a large body of information is available. Review of published work emphasizes research undertaken since publication of the review papers by Kottlowski, Cooley and Ruhe, and by Frye and Leonard in The Quaternary of the United States (Wright and Frey, 1965).}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, geomorphology, Quaternary stratigraphy, geomorphology, stratigraphy, proceeding, proceedings}, isbn = {0-87933-262-X}, author = {J. Hawley and Bachman, G. O. and Manley, K.}, editor = {Mahaney, W. C. (ed.)} } @proceedings {52233, title = {Quaternary history of Dona Ana County region, south-central New Mexico}, volume = {26th Field Conference}, year = {1975}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1975}, pages = {139-150}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, abstract = {The region discussed in this paper comprises south-central New Mexico and adjacent parts of Trans-Pecos Texas and Chihuahua, Mexico (Fig. 1). Emphasis is on Quaternary events and alluvial deposits in the Dona Ana County area of the Mexican Highlands section, Basin and Range province. Many of the local features mentioned herein are described in the road-log section of this guidebook, particularly at Day 2 and 3 tour stops. Aspects of Quaternary research in the area are also discussed in companion guidebook papers by Dick-Peddie, Hawley, Hoffer, Fox, Stone and Brown, and King and Hawley.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, Desert Project, geology, geology, environmental, geology, Quaternary, geomorphology, alluvial deposits, history,Quaternary, proceeding, proceedings}, author = {J. Hawley} } @proceedings {52391, title = {A quantitative ecology of the Jornada Experimental Range}, volume = {Science Series No. 6}, year = {1970}, month = {1970}, pages = {I-133--I-177}, publisher = {Range Science Department, Colorado State University}, abstract = {The area including the Jornada Range has been classified as semidesert grassland. The semidesert grassland extends over southeastern Arizona, southern New Mexico, western Texas and northern Mexico [the desert grassland of Shreve (1917) and Shantz and Zon (1924), and the desert plains of Clements (1920)]. The semidesert grassland does not occupy that entire area but occurs rather widely interspersed with other types. It occupies extensive plains areas, but it also typically occurs as broad belts around the base of many of the Southwestern mountain ranges. Although the region is termed "grassland," it is far from being an essentially unbroken expanse of grasses, as are the tall-end, mixed grass prairies. In some places, pure stands of grass prevail; in others, there are open savannas with grasses associated with oaks or mesquites. In still other places, the grasses are interspersed with a wide variety of low-growing trees or shrubs. Annual and perennial grasses and forbs, and shrubs are common. The semidesert grassland has long been considered as a climatically determined climax (Clements, 1920; Campbell, 1929; Whitfield and Anderson, 1938; Whitfield and Betner, 1938; Clements and Shelford, 1939; Gardner, 1951). Shreve (1917) regarded the area as transitional between a true grassland to the east and the shrub deserts to the west and south. On the basis of changes in a protected grassland area, Brown (1950) concluded that semidesert grassland was not climax but was maintained in part by some factor that was unfavorable to shrubs. Canfield (1948) and Buffington and Herbel (1965) found that once unpalatable woody plants are established, they become a relatively permanent part of the plant cover. More stable areas can undoubtedly be classified as grassland but other large areas would have to be classified as desert shrub or Chihuahuan Desert.}, keywords = {Jornada Experimental Range, quantitative ecology, semidesert grassland}, url = {/files/bibliography/124.pdf}, author = {C.H. Herbel and P.L. Dittberner and Bickle, T.S.} } @proceedings {52413, title = {Quaternary geology of the south-central New Mexico border region}, volume = {Circular 104}, year = {1969}, note = {//LOCAL//NONE//ProCite field[6]: In}, month = {1969}, pages = {89-115}, publisher = {New Mexico Bureau of Mines and Mineral Resources}, abstract = {In early to mid-Quaternary time, the intermontane basins of the south-central New Mexico border region were still internally drained. Environments of deposition ranged from alluvial-fan piedmont slopes to broad basin floors that were often sites of lacustrine sedimentation. In later stages of basin filling, local upland sediment sources were supplemented by the ancestral upper Rio Grande, which extended into the region by early Kansan time. Studies of vertebrate and invertebrate faunas and correlation of volcanic ash lenses indicate that basin filling in extensive areas adjacent to the Rio Grande Valley culminated in late Kansan to early Illinoian time. The complex of late Cenozoic basin fills predating Rio Grande Valley entrenchment comprises the Santa Fe Group. The Jornada and La Mesa geomorphic surfaces cap the Santa Fe sequence. Cyclic entrenchment of the Rio Grande was initiated after mid-Pleistocene integration of the lower and upper segments of the ancestral Rio Grande. Subsequently, four major, climatically controlled cycles of valley cutting have taken place. Aggradation of basin surfaces has continued in broad areas still not integrated with Rio Grande drainage. Parts of basin floors were occupied by large lakes during late Pleistocene pluvials. Significant structural deformation of basin- and valley-fill deposits and extrusion of basalts and maare formation in Mesilla bolson represent continuation of deep-seated disturbances in Quaternary time.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, geomorphology, Quaternary geology, proceeding, proceedings}, author = {J. Hawley and Frank E. Kottlowski} }