<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Ginzburg, Orit</style></author><author><style face="normal" font="default" size="100%">Berg, Naama</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Do long-lived ants affect soil microbial communities?</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">48</style></volume><pages><style face="normal" font="default" size="100%">227-233</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;This study was designed to test the hypothesis that desert ant species that build nests that remain viable at a particular point in space for more than a decade produce soil conditions that enhance microbial biomass and functional diversity. We studied the effects of a seed-harvester ant, &lt;em&gt;Pogonomyrmex rugosus&lt;/em&gt;, and two generalist ant species, &lt;em&gt;Aphaeonogaster cockerelli&lt;/em&gt; and &lt;em&gt;Myrmecocystus depilis&lt;/em&gt;, on soil microbial communities. Microbial biomass was higher in &lt;em&gt;P. rugosus&lt;/em&gt;-modified soils than in reference soils when soil water content was higher than 3%. Microbial biomass was either higher in reference soils or exhibited no difference in reference soils and nest-modified soils of &lt;em&gt;A. cockerelli &lt;/em&gt;and &lt;em&gt;M. &lt;/em&gt;&lt;em&gt;depilis&lt;/em&gt;. There were differences in microbial functional diversity and microbial community level physiological profiles (MicroResp method) between ant-nest-modified and reference soils of the three ant species on some sampling dates. Temporal pattenrs of soil microbial communities associated with the ant species resulted from differences in soil moisture, density, and species composition of the annual plant c0ommunities associated with the ant nests and in reference areas. Differences in annual plant communities associated with ant nests and surrounding areas resulted in different chemical inputs into the soil organic-matter pools. This study shows that generalizations about the effects of long-lived ant nests on soil biota in arid regions must consider feeding behaviors of the ant species and temporal patterns of rainfall.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2012-89968</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of simulated storm sizes and nitrogen on three Chihuahuan Desert perennial herbs and a grass</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/11-010.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">75</style></volume><pages><style face="normal" font="default" size="100%">861-864</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2011-89979</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>5</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Herbivore-plant interactions and desertification in arid lands</style></title><secondary-title><style face="normal" font="default" size="100%">All Flesh is Grass</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Cellular Origin, Life in Extreme Habitats and Astrobiology</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/10-037.pdf</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Springer-Verlas</style></publisher><pages><style face="normal" font="default" size="100%">239-256</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Arid lands around the world have experienced or are currently experiencing degradation that is known as desertification. Animal-plant interactions that have an effect on desertification are among the most important function of animals in arid ecosystems. Desertification has been defined as land degradation in arid and semiarid areas that is the result of various factors, including climate variation and human activities. The interactions between animals and plants affect desertification arid environments in a number of ways. These interactions may exacerbate desertification processes or contribute to the stability of desertified ecosystems. Some animal-plant interactions are direct, e.g., herbivory, while others are indirect, e.g., seed dispersal and soil modification. Animal-plant interactions that contribute to changes in the structure of plant communities or the spread of alien plant species may enhance some degradation processes such as soil erosion or contribute to soil stability and resistance to degradation.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2010-90092</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Barness, G.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of three species of Chihuahuan Desert ants on annual plants and soil properties</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/08-055.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">72</style></volume><pages><style face="normal" font="default" size="100%">392-400</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We tested the hypothesis that ant species, which occupy the same nest for a decade or longer, would modify nest soils by increasing soil nutrients and microorganisms resulting in increased biomass, density, cover and species richness of annual plants. We measured soil properties and annual plants on nest soils of three species of Chihuahuan Desert ants (Pogonomyrmex rugosus--seed harvester, Aphaenogaster cockerelli--generalist forager, and Myrmecocystus depilis--liquid collector-insect scavenger) in comparison to paired reference soils at several locations. There were no differences in nest and reference total soil nitrogen of M. depilis and of P. rugosus on three catena soils. Total soil nitrogen of nest-modified soils was higher than of reference soils of A. cockerelli and P. rugosus in a desert grassland site. Soil microbial biomass and respiration were not significantly different among ant species at most locations with the exception of P. rugosus at the base of the catena. Annual plant biomass was higher on M. depilis and A. cockerelli nest soils than on the reference soils. Annual plant biomass was higher on P. rugosus nest soils than on reference soils at the base of the catena and in the grassland but not at the mid-slope and top of the catena. The effects of long-lived ant colony nests on soil properties and vegetation vary in time and space but are independent of the feeding behavior of the ant species.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2008-90350</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Zaragoza, Salvador Rodriguez</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of temporally persistent ant nests on soil protozoan communities and the abundance of morphological types of amoeba</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">81-87</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We compared soil protozoan communities near ant nests with soil protozoans in reference soils 5mfrom the edge of ant mounds.Wesampled three species of Chihuahuan Desert ants that construct nests that persist for more than a decade: a seed harvester, &lt;i&gt;Pogonomyrmex rugosus&lt;/i&gt;, a liquid feeding honey-pot ant, &lt;i&gt;Myrmecocystus depilis&lt;/i&gt;, and a generalist forager, &lt;i&gt;Aphaenogaster cockerelli&lt;/i&gt;. Ant colonies were located on different topographic positions on catenas of two watersheds. Total protozoan abundance was higher in &lt;i&gt;P. rugosus &lt;/i&gt;nest soils at the top of a catena and in &lt;i&gt;A. cockerelli&lt;/i&gt; nest soils in a grassland than in the respective reference soils. There were qualitative and quantitative differences in protozoan communities associated with the nests of ants at all locations studied. Amoebae were the most abundant protozoans at all locations. Type 1 amoebae (flattened with sub-pseudopodia (like &lt;i&gt;Acanthamoeba&lt;/i&gt;)) occurred at the highest frequency and was the only amoeba type found in &lt;i&gt;M. depilis&lt;/i&gt; nest soils and &lt;i&gt;P. rugosus&lt;/i&gt; nest soils at the top of a catena. Nanoflagellates were associated with &lt;i&gt;P. rugosus&lt;/i&gt; and &lt;i&gt;M. depilis&lt;/i&gt; nest soils but were absent from reference soils. Ciliates, testate amoebae and nanoflagellates were absent from &lt;i&gt;A. cockerelli &lt;/i&gt;reference soils but were present in nest soils. The effects of ants on soil protozoan communities depend on the temporal persistence of the colony, nest building and food handling behavior, topographic position and soil type. © 2007 Elsevier B.V. All rights reserved.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2007-90428</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Aldon, Earl F.</style></author><author><style face="normal" font="default" size="100%">Freckman, Diana W.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Parker, Lawrence W.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of organic amendments on soil biota on a degraded rangeland</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1989</style></year></dates><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">56-60</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rehabilitation of degraded rangeland requires rebuilding the soil, including soil biota.  In this study wheat straw, bark and wood chips, and dried municipal sludge were placed on native range plots in northcentral New Mexico.     Organic amendments had little or no effects of decomposition of straw, litter respiration, soil respiration, biomass of soil microflora, and populations of most of the soil biota in the second year of the study.  The differences in soil nematode and microarthropod population densities and straw decomposition occurred only in the bark and wood chip mulched plots in year 1.  The absence of differences in year 2 may have been the result of below-average rainfall.  The wood chip bark mulch was visibly present at the end of year 2 but the other mulches were not.  There may be long-term benefits from application of recalcitrant mulches like wood chips and bark, but the less recalcitrant mulching like straw and low application rates of sludge produce no measurable benefit.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1989-91718</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Schaefer, Douglas</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The failure of nitrogen and lignin control of decomposition in a North American desert</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1985</style></year></dates><volume><style face="normal" font="default" size="100%">65</style></volume><pages><style face="normal" font="default" size="100%">382-386</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We measured mass losses of both buried and surface litter of six litter types: leaves of the perennial evergreen shrub, &lt;i&gt;Larrea tridentata&lt;/i&gt;, leaves of the winter deciduous perennials &lt;i&gt;Flourensia cernua, Prosopis glandulosa&lt;/i&gt; and &lt;i&gt;Chilopsis linearis&lt;/i&gt; ( a desert riparian species), and evergreen monocot, &lt;i&gt;Yucca elata&lt;/i&gt;, and a mixture of annual plants.  These species differed in lignin content and carbon-nitrogen ratios.  There was no correlation between rates of mass loss and percent lignin, carbon-nitrogen ration, or lignin-nitrogen ratio.  The leaves of &lt;i&gt;F. cernua&lt;/i&gt; and the mixed annuals exhibited the highest rates of mass loss.  Surface litter of &lt;i&gt;Y. elata&lt;/i&gt;, and the mixed annuals and &lt;i&gt;C. linearis&lt;/i&gt; exhibited higher mass loss than buried litter of the same species.  The patterns of mass loss occurring as a negative exponential and surface litter exhibiting low rates in winter and spring and high rates in summer.  There was no correlation between mass loss in surface bags that were field exposed for 1 month and actual evapotranspiration (AET) but there was a correlation between AET and mass losses in buried litter.  A model relating mass loss to AET and initial lignin content underestimated mass losses in all species examined.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1985-91930</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Microarthropods of a desert tabosa grass (&lt;i&gt;Hilaria mutica&lt;/i&gt;) swale</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1985</style></year></dates><volume><style face="normal" font="default" size="100%">114</style></volume><pages><style face="normal" font="default" size="100%">225-234</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We examined soil microarthropod populations inhabiting a clay-silt soil of a tabosa grass (&lt;i&gt;Hilaria mutica&lt;/i&gt;) swale in southern New Mexico....  Overall densities of microarthropod groups were correlated with soil moisture but many individual taxa were not.  The most numerous and frequently occurring taxa [nanorchestid, tydeid and bdellid mites (Progtigmata); &lt;i&gt;Aphelacarus&lt;/i&gt; sp. and &lt;i&gt;Cosmochthonius&lt;/i&gt; sp. (Cryptostigmata)] are common in all Chihuahuan desert habitats examined to date and are common in other North American desert areas.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1985-91940</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Santos, Perseu F.</style></author><author><style face="normal" font="default" size="100%">Elkins, Ned Z.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A comparison of surface and buried &lt;i&gt;Larrea tridentata&lt;/i&gt; leaf litter decomposition in North American hot deserts</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1984</style></year></dates><volume><style face="normal" font="default" size="100%">65</style></volume><pages><style face="normal" font="default" size="100%">278-284</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We conducted studies of mass losses from surface and buried litter bags in four North American hot desert areas to test the following hypotheses: (1) leaf litter disappearance in hot deserts is independent of actual evapotranspiration, (2) buried litter disappearance is a function of actual evapotranspiration, (3) the patter of microarthropod colonization of buried leaf litter is a function of the stage of decomposition, and (4) elimination of microarthropod results in reduced rates of decomposition and increased numbers of free-living nematodes.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1984-91956</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spatial and temporal relationships of soil microarthropods on a desert watershed</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1984</style></year></dates><volume><style face="normal" font="default" size="100%">26</style></volume><pages><style face="normal" font="default" size="100%">275-284</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">...we hypothesized that microarthropod densities and numbers of taxa would be highest at the base of a closed basin watershed where organic matter and water accumulate (run-on area) and lowest at the top of the watershed (run-off area), providing the soils sampled were under the same plant species....  we hypothesized that as the soils dried following a rain event, the number of taxa and population densities of microarthropods would remain high for longer periods at the base of the watershed than at the top.     The data collected in the study force us to reject our original hypotheses, i.e., that microarthropod population densities and number of taxa should be higher at the base of the watershed, exhibit a greater increase in size in response to precipitation and remain active for a longer time than on the upper slopes of the watershed.  The relationships found in this study were almost the reverse of those hypothesized.  Although soil organic matter and percent soil moisture were consistently higher at the base of the watershed, soil microarthropod populations were either lower than or equal to those found on the upper slopes.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1984-91979</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Elkins, Ned Z.</style></author><author><style face="normal" font="default" size="100%">Steinberger, Yosef</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Factors affecting the applicability of the AET model for decomposition in arid environments</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1982</style></year></dates><volume><style face="normal" font="default" size="100%">63</style></volume><pages><style face="normal" font="default" size="100%">579-580</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">There is considerable interest in the applicability of the model developed by Meentemeyer (1978), which predicts decomposition as a function of actual evapotranspiration (AET) and lignin, to environments other than forests.  Whitford et al. (1981&lt;i&gt;b&lt;/i&gt;) discussed exceptions to the Meentemeyer AET model in deserts and clearcut forests and concluded that in these environments, biological activity of soil microarthropod and termites, accounts for the deviations (higher rates) from the model.  We recently completed a study of decomposition in a semiarid desert-grassland transitional area that provides another independent test of the AET model.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1982-92059</style></accession-num></record></records></xml>