@inbook {50466, title = {Patterns of net primary production in Chihuahuan desert ecosystems}, booktitle = {Structure and Function of a Chihuahuan Desert Ecosystem: The Jornada Basin Long-Term Ecological Research Site}, year = {2006}, month = {July 1, 2006}, pages = {232-246}, publisher = {Oxford University Press}, organization = {Oxford University Press}, chapter = {11}, address = {New York, NY}, abstract = {The Jornada Basin of southern New Mexico has long been an important location for the study of productivity in semidesert ecosystems. Researchers have studied the magnitude and sustainability of plant production since the founding of the USDA Jornada Experimental Range (JER) in 1912. The consistent administration and research focus of the Jornada Experimental Range and of the Chihuahuan Desert Rangeland Research Center (CDRRC) have facilitated a number of long-term studies of vegetation dynamics and productivity. These long-term datasets are especially critical for understanding semiarid ecosystems, where interannual and decadal scale variation in climate is so great and where plant performance is so strongly constrained by the physical environment. Long-term data, including the net primary productivity data that are the focus of this chapter, are also essential for understanding the progression or, rather, degradation of ecosystem structure that has been called desertification.}, keywords = {1912, magnitude, plant, production, productivity, sustainability}, url = {/files/bibliography/06-062.pdf}, author = {L. Huenneke and W. H. Schlesinger}, editor = {Kris Havstad and L. Huenneke and W. H. Schlesinger} } @article {50893, title = {Desertification alters patterns of aboveground net primary production in Chihuahuan ecosystems}, journal = {Global Change Biology}, volume = {8}, year = {2002}, note = {//NMSU,USDA//LTER IV//}, month = {2002}, pages = {247-264}, abstract = {

The Chihuahuan desert of New Mexico has changed in historical times from semiarid grassland to desert shrublands dominated by Larrea tridentata and Prosopis glandulosa. Similar displacement of perennial grasslands by shrubs typifies desertification in many regions. Such structural vegetation change could alter average values of net primary productivity, as well as spatial and temporal patterns of production. We investigated patterns of aboveground plant biomass and net primary production in five ecosystem types of the Jornada Basin Long-Term Ecological Research (LTER) site. Comparisons of shrub-dominated desertified systems and remnant grass-dominated systems allowed us to test the prediction that shrublands are more heterogeneous spatially, but less variable over time, than grasslands.We measured aboveground plant biomass and aboveground net primary productivity (ANPP) by species, three times per year for 10 years, in 15 sites of five ecosystem types (three each in Larrea shrubland, Bouteloua eriopoda grassland, Prosopis dune systems, Flourensia cernua alluvial flats, and grass-dominated dry lakes or playas). Spatial heterogeneity of biomass at the scale of our measurements was significantly greater in shrub-dominated systems than in grass-dominated vegetation. ANPP was homogeneous across space in grass-dominated systems, and in most growing seasons was significantly more patchy in shrub vegetation. Substantial interannual variability in ANPP complicates comparison of mean values cross ecosystem types, but grasslands tended to support higher ANPP values than did shrub-dominated systems. There were significant interactions between ecosystem type and season.Grasslands demonstrated higher interannual variation than did shrub systems. Desertification has apparently altered the seasonality of productivity in these systems; grasslands were dominated by summer growth, while sites dominated by Larrea or Prosopis tended to have higher spring ANPP. Production was frequently uncorrelated across sites of an ecosystem type, suggesting that factors other than season, regional climate, or dominant vegetation may be significant determinants of actual NPP.

}, keywords = {article, articles, climate change, community dynamics, climate, Chihuahuan Desert, climate, desertification, climate, grassland, desertification, journal, journals, Larrea tridentata, net primary production, plant community, change, plant community, creosotebush, plant community, diversity, plant community, mesquite, plant community, productivity, plant community, tarbush, plant community, vegetation sampling, plant, environmental change, plant, Flourensia, plant, Larrea tridentata, plant, primary production, plant, productivity, plant, Prosopis, plants, net primary production, playa, productivity, playa, vegetation patterns, prosopis glandulosa}, doi = {10.1046/j.1365-2486.2002.00473.x}, url = {files/bibliography/JRN00354.pdf}, author = {L. Huenneke and John P. Anderson and M.D. Remmenga and W. H. Schlesinger} } @inbook {51009, title = {Deserts}, booktitle = {Global Biodiversity in a Changing Environment: Scenarios for the 21st Century}, year = {2001}, note = {//?//LTER IV// Updated 12/17/2005ProCite field[6]: In}, month = {2001}, pages = {201-222}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York, NY}, keywords = {book, books, chapter, chapters, desert, report, reports}, author = {L. Huenneke}, editor = {O. E. Sala and F.S. Chapin III and E. Huber-Sannwald} } @article {51010, title = {Spatial heterogeneity in Chihuahuan Desert vegetation: implications for sampling methods in semi-arid ecosystems}, journal = {Journal of Arid Environments}, volume = {47}, year = {2001}, note = {//NMSU,USDA//LTER IV//}, month = {2001}, pages = {257-270}, abstract = {

Patchiness of above-ground vegetation, such as that in semi-arid grasslands and shrublands, can pose problems in sampling plant cover, biomass and productivity. We present a method of measuring above-ground plant biomass and production that can be applied consistently among vegetation types and that generates seasonal, spatially-explicit results. Results from 15 sites within the Jornada Basin (Chihuahuan Desert, New Mexico, USA) confirm considerable patchiness and non-normal distributions of plant biomass, even in grasslands. However, tests of adequacy of sample size and of sample error associated with the regression-based estimates of biomass confirmed that the estimates of above-ground net primary productivity are sufficiently precise to be useful in comparisons of both shrub-dominated and grassland sites.

}, keywords = {article, articles, Bouteloua, net primary production, ecosystem, plant production, journal, journals, Larrea, net primary production, net primary production, plants, net primary production, Prosopis, net primary production, spatial heterogeneity, technique, aboveground NPP}, doi = {10.1006/jare.2000.0678}, url = {files/bibliography/JRN00345.pdf}, author = {L. Huenneke and Clason, Dennis and E. Muldavin} } @conference {51086, title = {Effects of plant removals on soil surface erosion in a Chihuahuan Desert shrubland}, booktitle = {85th Annual Meeting, Ecological Society of America}, year = {2000}, month = {August 6-10, 200}, pages = {290}, address = {Snowbird, UT}, abstract = {Humans are dramatically altering the patterns of biological diversity in semiarid ecosystems worldwide, in particular by altering the relative abundance of different growth forms (shrubs vs. perennial grasses) and by reducing the numbers of species within growth forms. We are exploring the impact of reduced plant diversity in experimental plots of creosotebush (Larrea tridentata) shrubland at the Jornada Basin LTER site near Las Cruces, NM, USA. In 1995, eight treatments of varying severity of plant community alteration were imposed on 25m x 25m plots (six replicates of each treatment); treatments ranged from no removals to extreme simplification of the perennial community (one shrub species, one grass species, one succulent, etc.). These treatments have been maintained since 1995. We have monitored soil erosion and sediment movement within these plots since spring 1996 by collecting sediment in pans at the downslope edge of each plot. Fine materials (particle diameter <2mm) dominate total soil movement (by weight), although larger particles are transported in this system, especially during the summer-fall season of intense episodic rainfall. Fine particle movement is higher in shrub removal and grass removal treatments than in controls during some seasons, especially in the summer. No statistically significant differences were detected during other seasons. Location on the slope with respect to local channels or arroyos contributes significantly to variation in the amount of material moving within a plot, as does the nature of vegetative cover and soil surface characteristics in the immediate vicinity of a collecting pan. Our results suggest the relationship between plant community structure and soil erosion rates is best examined at the scale of local patches.}, keywords = {Chihuahuan Desert, plant removal, shrubland, soil erosion}, author = {L. Huenneke and M. Buonopane and Bothern, L. and Jeffrey E. Herrick} } @conference {51085, title = {Jornada Basin LTER: Linkages in semiarid landscapes}, booktitle = {85th Annual Meeting, Ecological Society of America}, year = {2000}, month = {August 8-10, 200}, pages = {Abstract p. 396}, address = {Snowbird, UT}, abstract = {Chihuahuan Desert landscapes exemplify the ecological conditions, vulnerability, and management issues found in semiarid regions around the globe. The goal of the JRN-LTER program is to identify the key factors controlling ecosystem dynamics in semiarid landscapes with the objective of understanding the causes and consequences of desertification. Previous work has focused primarily at the scale of a single plant-interspace and the redistribution of resources at that scale. Our central hypothesis for LTER IV is that landscape position and linkages among landscape units exert important influences on ecosystem dynamics and biotic patterns. We propose to build upon our understanding of resource redistribution at the plant-interspace scale in several ways. We will synthesize existing long-term data with new studies on linkages among landscape units. We will conduct simulation model analyses to test the relative importance of within- versus between-unit processes. We will initiate studies of landscape fluxes of water, nutrients, and organisms to evaluate key processes affecting ecosystem dynamics at this scale. We will also employ remote sensing to assess fluxes and processes at larger spatial scales. Cross-site studies will be used to test the generality of our hypotheses for application to management and remediation of semiarid ecosystems and desertified landscapes.}, keywords = {desertification, ecosystem dynamics, LTER, remote sensing, semiarid, simulation model}, author = {L. Huenneke and Kris Havstad and Jeffrey E. Herrick and David C. Lightfoot and Curtis H. Monger and Debra C. Peters and A. Rango} } @proceedings {51161, title = {A helping hand: Facilitation of plant invasions by human activities}, year = {1999}, note = {// //LTER III//ProCite field[6]: In}, month = {1999}, address = {Townsville, Australia}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, human impacts, human impacts, plant invasion, plant invasion, proceeding, proceedings}, author = {L. Huenneke} } @inbook {51287, title = {Outlook for plant invasions: interactions with other agents of global change}, booktitle = {Assessment and management of plant invasions}, year = {1997}, note = {//NONE//LTER-III//ProCite field[6]: In}, month = {1997}, pages = {95-103}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York}, abstract = {

It is the daunting task of this chapter to peer into the future and speculate about the prospects for plant invasion. We know that the globe is changing in its physical, biological, and cultural features. What impact might these changes have on the rate at which plant invaders arrive in our natural communities and on the effect they have there? One can certainly list some of the major changes underway in the environment and review the ways in which the arrival or establishment of invaders might be affected; that is how I will begin. However, it is clearly unwise to think of these factors in isolation from one another, and so I go on to discuss possible synergistic relationships among the factors. I will also try to put into a larger management context the entire issue of plant invasions as affected by global change.

}, keywords = {book, books, chapter, chapters, global change, plant invasion, plant invasion, plant, exotics, report, reports}, url = {files/bibliography/JRN00248.pdf}, author = {L. Huenneke}, editor = {Luken, J. O. and Thieret, J. W.} } @book {51351, title = {Ecosystem function of biodiversity in arid ecosystems}, series = {Functional roles of biodiversity: A global perspective}, year = {1996}, note = {//NMSU,USDA//LTER-III//ProCite field[6]: InProCite field[30]: Mooney, H. A.Cushman, J. H.Medina, E.Sala, O. E.Schulze, E.-D. , eds.}, month = {1996}, pages = {99-128}, publisher = {John Wiley \& Sons Ltd}, organization = {John Wiley \& Sons Ltd}, address = {New York}, abstract = {Our discussion applies to both so-called hot or semi-tropical deserts and to cool or temperate arid zones; we exclude from discussion the polar deserts, where temperature constrains plant growth during most of the year. We recognize that aridity may arise from different combinations of regional climate, topography, and so on.... In this chapter we focus on a description of the nature and function of biodiversity, at several levels of organization, within these systems.}, keywords = {biodiversity, ecosystem, book, books, chapter, chapters, ecosystem dynamics, abiotic factors, ecosystem dynamics, biotic responses, ecosystem dynamics, invertebrates, ecosystem dynamics, water, ecosystem function, ecosystem, biodiversity, ecosystem, fungal community, ecosystem, plant production, ecosystem, processes, ecosystem, soil microorganisms, grazing, ecosystem function, plant production, report, reports, soil nutrients, soil structure}, author = {L. Huenneke and I. R. Noble} } @proceedings {51350, title = {Shrublands and grasslands of the Jornada Long-Term Ecological Research Site: desertification and plant community structure in the northern Chihuahuan Desert}, volume = {Gen. Tech. Rep. INT-GTR-338}, year = {1996}, note = {//NMSU,USDA//LTER-III//ProCite field[6]: InProCite field[8]: Compilers}, month = {May 23-25, 1995}, pages = {48-50}, publisher = {U.S. Department of Agriculture, Forest Service, Intermountain Research Station}, address = {Las Cruces, NM}, abstract = {Semidesert grasslands of southern New Mexico have been replaced in this century with shrublands (chiefly creosote bush and mesquite). The Jornada Long-Term Ecological Research Program has been monitoring aboveground plant productivity, plant species composition, and other aspects of ecosystem function in 15 sites. Plant diversity differs significantly among vegetation types, with grasslands being the most diverse. Aboveground net primary productivity does not differ significantly among vegetation types. Productivity is correlated with plant species richness in some seasons; however, diversity has not been correlated with smaller fluctuation of production between years in the first few years of study. These results have implications for sustainable management of diversity and of productivity.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, desertification, plant community, diversity, plant community, productivity, plant community, structure, plant, diversity, plant, productivity, proceeding, proceedings}, author = {L. Huenneke}, editor = {J.R. Barrow and McArthur, E.D. and R. E. Sosebee and R. J. Tausch} } @inbook {51404, title = {Arid and semi-arid lands}, booktitle = {Global Biodiversity Assessment}, year = {1995}, note = {//OTHER//LTER III//}, month = {1995}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, address = {Cambridge}, keywords = {biodiversity, water, book, books, chapter, chapters, report, reports, water, biodiversity}, author = {L. Huenneke and I. R. Noble}, editor = {V. H. Heywood} } @proceedings {51407, title = {Ecological impacts of plant invasion in rangeland ecosystems}, volume = {BLM/OR/WA/PT-95/048+1792}, year = {1995}, note = {//OTHER//NONE// Updated 12/17/2005ProCite field[2]: Associate ProfessorProCite field[6]: In}, month = {January 17, 1995}, pages = {10-14 pp.}, address = {Held in conjunction with the annual meeting for The Society of Range Management on January 17, 1995}, abstract = { Invasive non-native species, both plants and animals, have become major management problems in North America (OTA 1993). Alien (non-native) plants can have harmful impacts in natural and semi-natural ecosystems as well as in agricultural settings; these "environmental weeds" are the result of both deliberate importations (e.g., for forage crops or as ornamentals) and accident. These importations continue, and the number of problematic species is increasing all the time. The arrival of new species has the potential to alter ecological relationships and processes, with undesirable impacts on management and conservation concerns. The objective of this paper is to review the ecological impacts of invasive non-native plants in natural systems, with a focus on semi-arid rangelands. I will outline measures of ecosystem health in rangelands, and discuss how they can be influenced by invasive plants. I will also present some guidelines for action, based on what we know of the ecology of these invading weeds.}, keywords = {abstract, abstracts, conference, conference proceedings, conferences, plant invasion, plant, non-native, proceeding, proceedings, rangeland management, rangeland, ecosystem}, author = {L. Huenneke} } @inbook {51405, title = {Ecosystem function of biodiversity in Arid and semi-arid lands}, booktitle = {Global biodiversity assessment}, year = {1995}, note = {//OTHER//NONE//ProCite field[6]: In}, month = {1995}, pages = {349-354}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, address = {Cambridge, England}, abstract = {

In arid lands, water availability (precipitation vs. evaporative demand) imposes severe constraints on biological activity. Precipitation is characterized by unpredictability in time and space as well as by low total amounts (Noy-Meir 1974). Semi-arid ecosystems differ from true arid areas in structure and in the rate and regulation of ecosystem processes. We differentiate between these two, and highlight cases of conversion from semi-arid to arid lands (desertification; Verstraete and Schwartz 1991). Biodiversity, reflected in species richness, is moderately high in semi-arid regions and declines with increasing aridity for most taxa (Shmida 1985; Pianka and Schall 1981; O\&$\#$39;Brien 1993). Certain taxa are diverse relative to other biomes (e.g. predatory arthropods, ants and termites, grasshoppers, snakes and lizards, rodents, annual plants), but there is substantial variation in the richness of particular taxa among the deserts of different continental areas. The abundance and activity of desert organisms are \&$\#$39;pulsed\&$\#$39; in correspondence with episodes of high moisture availability (Noy-Meir 1973; Louw and Seely 1982); while the prevalence of dormancy, cryptobiosis, aestivation and other modes of escaping harsh conditions means that most of the biodiversity of arid regions can be impossible to census or sample during most time periods.

}, keywords = {biodiversity, book, books, chapter, chapters, ecosystem, biodiversity, report, reports, water, biodiversity}, author = {L. Huenneke and I. R. Noble}, editor = {V. H. Heywood and Watson, R. T.} } @inbook {51406, title = {Effects of biodiversity on water distribution and quality}, booktitle = {Global biodiversity assessment}, year = {1995}, note = {//OTHER//NONE//ProCite field[6]: In}, month = {1995}, pages = {412-417}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, address = {Cambridge, England}, abstract = {

Water is essential to all living organisms, and in turn the biosphere plays a crucial role in the transportation, transformation and redistribution of water on local and regional scales. In terrestrial ecosystems, vegetation plays the primary role in transferring water from the soil to the atmosphere; plants and animals also have significant effects on the movement of water into the soil. In terrestrial systems, living organisms often regulate the magnitude and rate of flow of water from one site to another; similar effects occur in some aquatic ecosystems. In both terrestrial and aquatic systems the biota can have measurable impacts on water quality (e.g. on composition of solutes, abundance and nature of particulates). Unfortunately there are few experimental studies exploring the links between biodiversity and water. Clearly, though, differences among organisms and communities in physiology, phenology and structure determine the type and magnitude of biotic effects. The text below summarizes some of the major influences of species and communities on water fluxes and water quality.

}, keywords = {biodiversity, book, books, chapter, chapters, ecosystem, biodiversity, report, reports, water, biodiversity}, author = {L. Huenneke}, editor = {V. H. Heywood and Watson, R. T.} }