<?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%">Nash, M. S.</style></author><author><style face="normal" font="default" size="100%">Bradford, D.F.</style></author><author><style face="normal" font="default" size="100%">Franson, S.E.</style></author><author><style face="normal" font="default" size="100%">Neale, A.C.</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Heggem, D.T.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Livestock grazing effects on ant communities in the eastern Mojave Desert, USA</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%">2004</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/04-076.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">199-213</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effects of livestock grazing on composition and structure of ant communities were examined in the eastern Mojave Desert, USA for the purpose of evaluating ant communities as potential indicators of rangeland condition. Metrics for ant communities, vegetation, and other ground-cover elements were evaluated as a function of distance from livestock water tanks, which represents a gradient in level of livestock activity in desert settings. Data were collected at six isolated water tanks used by cattle during early summer, with seven plots (90m × 90m; 100 pitfall traps) per tank.   Thirty-eight species of ants were recorded, with an average of 14 ant species per plot. Ant species richness did not differ as a function of distance from the water tank. Also, overall species composition, as measured by a similarity index for species presence/absence for paired-comparisons of plots, did not show differences attributable to the gradient in grazing impact. In contrast, the relative abundance of several taxa and functional groups was significantly related to distance from the water tank. The predominant pattern was for the greatest abundance to occur at the water tank, with little difference in ant abundance among plots away from the water tank. This pattern was shown by the abundant ants species, &lt;i&gt;Conomyrma bicolor&lt;/i&gt; and &lt;i&gt;Pheidole tucsonica,&lt;/i&gt; and the groups &lt;i&gt;Conomyrma&lt;/i&gt; spp., &lt;i&gt;Pheidole&lt;/i&gt; spp., homopteran tenders, and plant foragers. However, two species, &lt;i&gt;Aphaenogaster megommata&lt;/i&gt; and &lt;i&gt;Monomorium wheelerorum&lt;/i&gt; showed the greatest relative abundance at a distance away from the water tank. A number of ant metrics were significantly related to ground-cover metrics (&lt;i&gt;R&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt;&gt; 0.5). Organic debris was the variable most frequently related significantly to ant abundance metrics, always in a positive direction, followed by cover for perennial grasses, annual forbs, and shrubs, and bare patch size. Ant community metrics in the study region appear to have little potential to serve as indicators of rangeland condition because differences were evident primarily in severely degraded localized conditions rather than in intermediate widespread conditions.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2004-90674</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%">Nash, M. S.</style></author><author><style face="normal" font="default" size="100%">Whitford, W. G.</style></author><author><style face="normal" font="default" size="100%">Bradford, D.F.</style></author><author><style face="normal" font="default" size="100%">Franson, S.E.</style></author><author><style face="normal" font="default" size="100%">Neale, A.C.</style></author><author><style face="normal" font="default" size="100%">Heggem, D.T.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Ant communities and livestock grazing in the Great Basin, USA</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%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science?_ob=MImg&amp;_imagekey=B6WH9-45RFHT2-S-1&amp;_cdi=6845&amp;_user=1496926&amp;_orig=browse&amp;_coverDate=12%2F31%2F2001&amp;_sk=999509995&amp;view=c&amp;wchp=dGLzVzz-zSkzV&amp;md5=3c8f42de3cd48efc80a3999bc5e7c04e&amp;ie=/sdarticle.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">49</style></volume><pages><style face="normal" font="default" size="100%">695-710</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities.  The study was conducted in two areas in the Great Basin: a sagebrush-steppe in southeastern Idaho (n = 30 sites) and salt-desert shrub in western Utah (n = 27 sites).  Sites were selected based on known rangeland conditions (i.e., good, fair, poor) associated with livestock grazing.  Ant communities differed considerably between the two study areas.  Collectively, more ant species occurred at the Idaho sites (30) than at the Utah sites (21), relatively few species (8) occurred in both areas, species richness was significantly greater at the Idaho sites (mean = 12(.)0 species) than the Utah sites (mean = 6(.)9 species), and Formica spp. were diverse (total of 15 species) at the Idaho sites but rate (1 species) at the Utah sites.  In Idaho, all species collectively, generalists and Formica spp., were significantly less abundant on sites in poor condition than that on sites in good or fair condition; whereas in Utah, seed harvesters and Pheidole spp. were significantly more abundant on sites in poor condition than on sites in good or fair condition.  In Idaho, species richness was significantly lower on sites in poor condition.  In Idaho, species richness and relative abundances of several ant groups were significantly related to bare patch size and parameters for cover or species richness of several vegetation groups.  In contract to the comparisons involving sites in poor condition, no differences in any communities in either Idaho or Utah were evident between sites in good and fair condition.  Thus, the ant communities responded only to large changes in rangeland condition and to large differences in climatic/edaphic conditions between the two areas.  Hence, ant community metrics appear to have limited utility as indicators of rangeland condition in the Great Basin.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2001-91056</style></accession-num></record></records></xml>