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latest article added on December 2013

ArticleFirst AuthorPublished
Ecophysiological responses of Chihuahuan desert grasses to fireAllred, B.W.2008

Ecophysiological responses of Chihuahuan desert grasses to fire

Keywords

Aristida purpurea ; Bouteloua eriopoda ; Nitrogen ; Photosynthesis

Abstract

To better understand the effects of fire in the Chihuahuan desert, gas exchange characteristics of two dominant grass species, Bouteloua eriopoda and Aristida purpurea, and soil nitrogen availability were studied in response to prescribed fire at the Jornada Experimental Range in southern New Mexico. Burned and unburned plant individuals were measured before and after fire. Rates of net photosynthesis and stomatal conductance were highest in burned individuals, with those of A. purpurea exceeding B. eriopoda. Soil nitrogen supply rates increased compared to unburned controls. Similar to other grasslands where fire is common, physiological characteristics of vegetation responded positively. These adaptations indicate that fire may be beneficial in the preservation and restoration of native grasses.

Authors

B.W. Allred, K.A. Snyder

Year Published

2008

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2008.06.008

Seed harvester ants (Pogonomyrmex rugosus) as “pulse” predators.Whitford, W.G.2007

Seed harvester ants (Pogonomyrmex rugosus) as “pulse” predators.

Keywords

Beameria vanosa ; Foraging ecology ; Grass cicadas

Abstract

Seed harvesting ants, Pogonomyrmex rugosus, collected grass cicadas at a high rate (>5 min-;1 taken into the nest) at one location where cicada emergence exceeded 3 m-;2. Dry conditions in the winter-spring resulted in no annual plants in the northern Chihuahuan Desert. P. rugosus colonies were inactive in areas where grass cicada emergence was less than 1 m-;2. P. rugosus initiate intense predatory activity in response to pulse of large numbers of prey. This study demonstrates that predatory behavior of seed harvesting ants is not limited to incidental encounters with prey during seed harvesting activities. Pulse predation demonstrates the importance of protein to seed harvester ant colonies.

Authors

W.G. Whitford, E. Jackson

Year Published

2007

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2007.01.005

Drought Leads to Collapse of Black-Tailed Prairie Dog Populations Reintroduced to the Chihuahuan Desert.Facka, Aaron N.2010

Drought Leads to Collapse of Black-Tailed Prairie Dog Populations Reintroduced to the Chihuahuan Desert.

Keywords

black-tailed prairie dog;Chihuahuan Desert;conservation plan;Cynomys ludovicianus;historic range;population collapse;population dynamics;reintroduction

Abstract

Recently, a conservation strategy developed to restore populations of black-tailed prairie dog (Cynomys ludovicianus) suggested reintroducing animals into the Chihuahuan Desert grasslands of the southwestern United States. Rainfall in desert habitats is lower and more variable compared to rainfall near the center of the prairie dog's range. Additionally, peak rainfall comes months after prairie dogs reproduce in these desert systems. Thus, southwestern populations may be less prolific and fluctuate more than those found in northerly climes. Using mark-recapture and mark-resight techniques, we estimated reproduction and monthly survival from 577 individuals inhabiting 6 reintroduced colonies from 2003 to 2005 in the northern Chihuahuan Desert. During 2003 precipitation was 64% of the long-term average, whereas both 2004 and 2005 had near-average precipitation. Probability that a female became pregnant, number of juvenile prairie dogs emerging from maternity burrows, and date of emergence were all correlated to adult female body mass. Adult monthly survival decreased from >0.95 during spring to 0.70 in summer 2003, following a rapid loss in adult body mass that coincided with low precipitation. In 2003 monthly juvenile survival was near zero on 2 of the 3 largest colonies and growth rates of juveniles were half that of subsequent years. Estimated population size declined by 68% (range = 18-91%) from 2003 to 2004, and 5 of 6 populations declined an average of 75% from their original introduction size. Prairie dog populations in desert environs may have a high risk of extirpation caused by weather patterns indicative of desert climates. Our results are important for those managers involved in the conservation of prairie dogs and we suggest that regional differences should be carefully considered prior to any reintroduction effort.

Authors

Facka, Aaron N., Gary W. Roemer, Verity L. Mathis, Michael Kam and Eli Geffen.

Year Published

2010

Publication

Journal of Wildlife Management

Locations
DOI

10.2193/2009-208

Modeling the effects of historical vegetation change on near-surface atmosphere in the northern Chihuahuan Desert.Beltrán-Przekurat, Adriana2008

Modeling the effects of historical vegetation change on near-surface atmosphere in the northern Chihuahuan Desert.

Keywords

Atmosphere-biosphere interactions ; Energy fluxes ; Jornada Experimental Range ; Land-atmosphere interactions ; Regional climate modeling simulations ; Semiarid areas ; Surface fluxes ; Vegetation changes

Abstract

Our goal was to evaluate effects of broad-scale changes in vegetation from grasslands to shrublands over the past 150 years on near-surface atmosphere over the Jornada Experimental Range in the northern Chihuahuan Desert, using a regional climate model. Simulations were conducted using 1858 and 1998 vegetation maps, and data collected in the field. Overall, the vegetation shift led to small changes in sensible heat (SH) and an increase in latent heat (LH). The impacts of shrub encroachment depended on shrubland type: conversion from grass to mesquite cools the near-surface atmosphere and from grass to creosotebush warms it. Higher albedo of mesquite relative to grasses reduced available energy, which was dissipated mainly as LH due to the deeper root system in mesquite. In creosotebush-dominated areas, a decrease in albedo, an increase in roughness length and displacement height contributed to the SH increase and warmer temperatures. Sensitivity simulations showed that an increase in soil moisture content enhanced shrub LH and a reduction in mesquite cover enhanced the temperature differences. The observed shift in vegetation led to complex interactions between land and surface fluxes, demonstrating that vegetation itself is a weather and climate variable as it significantly influences temperature and humidity.

Authors

Adriana Beltrán-Przekurat, Roger A. Pielke Sr., Debra P.C. Peters, Keirith A. Snyder, Albert Rango

Year Published

2008

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2008.05.012

Landscape-scale patterns of black-throated sparrow (Amphispiza bilineata) abundance and nest successPidgeon, AM2003

Landscape-scale patterns of black-throated sparrow (Amphispiza bilineata) abundance and nest success

Keywords

abundance; Amphispiza bilineata; Black-throated Sparrow; Chihuahuan Desert; ecological trap; landscape; nest success; population sink; scale; spatial pattern; temporal pattern

Abstract

Analyses of avian demographic patterns across entire, contiguous landscapes are rare, but such analyses are important for understanding population dynamics. We selected the Black-throated Sparrow in the northern Chihuahuan Desert as a model to test patterns of abundance and nest success. across a landscape. We integrated abundance, nest density, and nesting success measured on sampling plots with a classified satellite map of the distribution of seven habitat types to analyze spatial and temporal patterns contributing to the population dynamics of this species. Adult relative abundance ranged from < 0.01). There was no correlation between nest success and adult relative abundance. While mesquite habitat contained about one-third of all adults in the three years of the study, it contributed as. little as 10% of successful nests. In creosotebush, the relative contribution to both adult abundance and successful nests was relatively high. Mesa grassland contained relatively few adults, but up to 44% of successful nests. We discuss how habitat selection theory suggests mechanisms for the observed patterns. Mesquite appears to be a population sink for Black-throated Sparrows and may be, an ecological trap. While we do not propose that there is cause for conservation concern for this widespread species, our results, underscore the pitfalls associated with using adult abundance as an indicator of habitat quality. The method presented here is applicable for man), species and ecosystems and, thus, may be an important tool for conservation and management, as well as a new avenue for scientific investigation of landscape-level population dynamics.

Authors

Pidgeon, AM; Radeloff, VC; Mathews, NE

Year Published

2003

Publication

Ecological Applications

Locations
DOI

10.1890/1051-0761(2003)013[0530:LSPOBT]2.0.CO;2

This article contributed by:

Ecological Society of America

Olycella aff. junctolineella (Lepidoptera: Pyralidae) florivory on Opuntia microdasys, a Chihuahuan Desert endemic cactus.Piña, Hugo H.2010

Olycella aff. junctolineella (Lepidoptera: Pyralidae) florivory on Opuntia microdasys, a Chihuahuan Desert endemic cactus.

Keywords

Arid environments ; Biological interactions ; Floral biology ; Resource addition experiments ; Watering

Abstract

The object of this study was to provide the first data on the natural history of the little known plant-florivore interaction between Opuntia microdasys and Olycella aff. junctolineella larvae and to study interindividual variability in the number of reproductive structures attacked as a function of plant resource availability.

Authors

Hugo H. Piña, Carlos Montaña, María del Carmen M

Year Published

2010

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2010.01.008

Effects of simulated storm sizes and nitrogen on three Chihuahuan Desert perennial herbs and a grass.Whitford, W.G.2011

Effects of simulated storm sizes and nitrogen on three Chihuahuan Desert perennial herbs and a grass.

Keywords

Abundance ; Biomass ; Fertilization ; Irrigation

Abstract

Establishment and growth of three perennial herbs and a small tussock grass were studied in an experiment that provided simulated rainfall of 6 mm week-1 or 25 mm once per month and nitrogen fertilization in combination with the different simulated rainfall regimes. Wild onion, Allium macropetalum, failed to establish in plots receiving 25 mm month-1 simulated rainfall. The perennial composite, Bahia absinthifolia, occurred at higher densities in plots that were not irrigated but there were no differences in biomass in any of the irrigation or fertilization treatments. Desert holly, Perezia nana, failed to establish in nitrogen fertilized plots and developed higher abundance and biomass in plots receiving 25 mm month-1. Nitrogen fertilization had either no effect or an adverse effect on the perennial herbs. The tussock grass, Dasychloa pulchella exhibited highest abundance and biomass with 6 mm week-1 added water plus nitrogen. Since global climate change will affect both rain storm frequency and size and atmospheric nitrogen deposition, the results of this study are applicable to understanding vegetation responses climate change.

Authors

W.G. Whitford, Y. Steinberger

Year Published

2011

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2011.03.007

Palynology, radiocarbon dating, and woodrat middens: New applications at Hueco Tanks, Trans-Pecos Texas, USA.Hall, S.A.2010

Palynology, radiocarbon dating, and woodrat middens: New applications at Hueco Tanks, Trans-Pecos Texas, USA.

Keywords

Artemisia ; Chihuahuan Desert ; Pollen analysis ; Quaternary ; Radiocarbon dating ; Woodrat middens

Abstract

Pollen analysis of two woodrat middens from Hueco Tanks, El Paso County, Texas, dated 10,140 +/- 70 and 7170 +/- 70 14C years BP, shows late persistence of the regional glacial-age Artemisia steppe vegetation in what is historically desert shrub grassland of the northern Chihuahuan Desert. Local populations of Pinus were gone by the end of the Pleistocene, and creosotebush (Larrea) and mesquite (Prosopis) appeared in the local vegetation by mid-Holocene time. Juniperus can be strongly over-represented in midden pollen assemblages due to harvesting of cone-bearing twigs by woodrats. AMS radiocarbon dates on very small samples of midden matrix used for pollen analysis are 3400 and 2200 14C years younger than dates on plant macrofossils from the same middens. Juniperus over-representation in pollen percentages and age differences between pollen and macrofossil content must be taken into account when interpreting the palynology of woodrat middens.

Authors

S.A. Hall, D.H. Riskind

Year Published

2010

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2009.04.012

Burrowing rodents increase landscape heterogeneity in a desert grassland.Davidson, A.D.2008

Burrowing rodents increase landscape heterogeneity in a desert grassland.

Keywords

Banner-tailed kangaroo rats ; Biodiversity ; Ecosystem engineers ; Gunnison's prairie dogs ; Keystone species

Abstract

Animals that modify their environment through engineering and herbivory have important impacts on ecosystems, yet the interactive roles of such species have rarely been studied. We studied the comparative and interactive effects of two burrowing herbivorous rodents, Gunnison's prairie dogs (Cynomys gunnisoni) and banner-tailed kangaroo rats (Dipodomys spectabilis), on vegetation where they co-occurred in a Chihuahuan Desert grassland. We found that their effects remained distinct and, thus, non-substitutable, where they co-occurred. The rodents differentially altered plant community structure relative to their different mound types, herbivory, and spatial scales of disturbance. Vegetation structure and plant species assemblages differed between mound and landscape patches occupied by prairie dogs and kangaroo rats. Where both species co-occurred, there was more soil disturbance, organic material from their fecal pellets, forb cover, and activity by other animals. The combined effect of these rodents increased the landscape heterogeneity and plant species richness by creating a mosaic of different habitat patches on the landscape. Our results demonstrate that these rodents had complementary, additive effects where they co-occurred, and suggest that multiple habitat-modifying species, especially those that play large ecological roles, can have important interactive effects on community structure and biodiversity.

Authors

A.D. Davidson, D.C. Lightfoot

Year Published

2008

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2007.12.015

Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert.Housman, D.C.2006

Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert.

Keywords

Microbiotic soil crust ; Chlorophyll fluorescence ; Acetylene reduction ; Photosynthesis

Abstract

Biological soil crusts (cyanobacteria, mosses and lichens collectively) perform essential ecosystem services, including carbon (C) and nitrogen (N) fixation. Climate and land-use change are converting later successional soil crusts to early successional soil crusts with lower C and N fixation rates. To quantify the effect of such conversions on C and N dynamics in desert ecosystems we seasonally measured diurnal fixation rates in different biological soil crusts. We classified plots on the Colorado Plateau (Canyonlands) and Chihuahuan Desert (Jornada) as early (Microcoleus) or later successional (Nostoc/Scytonema or Placidium/Collema) and measured photosynthesis (Pn), nitrogenase activity (NA), and chlorophyll fluorescence (Fv/Fm) on metabolically active (moist) soil crusts. Later successional crusts typically had greater Pn, averaging 1.2-1.3-fold higher daily C fixation in Canyonlands and 2.4-2.8-fold higher in the Jornada. Later successional crusts also had greater NA, averaging 1.3-7.5-fold higher daily N fixation in Canyonlands and 1.3-25.0-fold higher in the Jornada. Mean daily Fv/Fm was also greater in later successional Canyonlands crusts during winter, and Jornada crusts during all seasons except summer. Together these findings indicate conversion of soil crusts back to early successional stages results in large reductions of C and N inputs into these ecosystems.

Authors

D.C. Housman, H.H. Powers, A.D. Collins, J. Belnap

Year Published

2006

Publication

Journal of Arid Environments

Locations
DOI

10.1016/j.jaridenv.2005.11.014

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