<?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%">Peters, Debra C.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Sala, Osvaldo E.</style></author><author><style face="normal" font="default" size="100%">Anderson, John P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Directional climate change and potential reversal of desertification in arid and semiarid ecosystems</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><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/12-002.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">151-163</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Our objective was to determine if long-term increases in precipitation can maintain grasslands susceptible to desertification, and initiate a reversal of historic regime shifts on desertified shrublands. Perennial grass production and species richness in a multi-year wet period were hypothesized to be greater than expected based on precipitation in a sequence of dry years. These responses were expected to differ for grasslands and shrublands with different dominant species and topo-edaphic properties. Long-term trends in desertification were documented using vegetation maps beginning in 1858, 1915, 1928, and 1998). These trends were compared with herbaceous and woody species responses to a sequence of dry (1994&amp;ndash;2003) and wet years (2004&amp;ndash;2008) for two grassland (uplands, playas) and three desertified shrubland types (honey mesquite, creosotebush, tarbush) in the Chihuahuan Desert. Analyses showed that both types of grasslands decreased in spatial extent since 1858 whereas areas dominated by mesquite or creosotebush increased. Production of upland grasslands in the wet period was greater than expected based on responses during the dry period whereas the relationships between species richness and precipitation was the same for both periods. Precipitation was not important to responses in playa grasslands in either period. For all ecosystem types, the production response in wet years primarily was an increase in herbaceous plants, and the most pronounced responses occurred on sandy sites (upland grasslands, mesquite shrubland). Results suggest that multiple wet years are needed to initiate a sequence of grass establishment and survival processes that can maintain upland grasslands without management inputs and lead to a state change reversal in desertified shrublands. Restoration strategies need to take advantage of opportunities provided by future climates while recognizing the importance of ecosystem type.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2012-89964</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%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Blair, J.M.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Peters, Debra P.C.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Cross-site comparisons of precipitation and surface water chemistry</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86849</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Fraser, W.R.</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author><author><style face="normal" font="default" size="100%">Ohman, M.D.</style></author><author><style face="normal" font="default" size="100%">Rassweiler, A.</style></author><author><style face="normal" font="default" size="100%">Holbrook, S.J.</style></author><author><style face="normal" font="default" size="100%">Schmitt, R.J.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Cross-site comparisons of state change dynamics</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86850</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%">Yao, J</style></author><author><style face="normal" font="default" size="100%">O.E. Sala</style></author><author><style face="normal" font="default" size="100%">Peters, Debra P.C.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Cross-site studies &quot;by design&quot;: Experiments and observations that provide new insights</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86851</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Chapin, F. Stuart</style></author><author><style face="normal" font="default" size="100%">Tepley, A.J.</style></author><author><style face="normal" font="default" size="100%">Swanson, F.J.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Disturbance regimes and ecological responses across sites</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agrigultural Research Service Report</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86853</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%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Baker, K.S.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">History and organization of the EcoTrends Project</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86861</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Ohman, M.D.</style></author><author><style face="normal" font="default" size="100%">Waide, R.B.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Collins, Scott L.</style></author><author><style face="normal" font="default" size="100%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" 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size="100%">Collins, Scott L.</style></author><author><style face="normal" font="default" size="100%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" size="100%">Knapp, A</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></title><secondary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">United States Department of Agriculture (USDA)</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86867</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Ohman, M.D.</style></author><author><style face="normal" font="default" size="100%">Waide, R.B.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Collins, Scott L.</style></author><author><style face="normal" font="default" size="100%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" size="100%">Knapp, Alan K.</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: An introduction to cross-site comparisons and relevance to global change studies</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86868</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Ohman, M.D.</style></author><author><style face="normal" font="default" size="100%">Waide, R.B.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Collins, Scott L.</style></author><author><style face="normal" font="default" size="100%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" size="100%">Knapp, Alan K.</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term trends in human demography and economy across sites</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, 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C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" size="100%">Knapp, Alan K.</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term trends in precipitation and surface water chemistry</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86870</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%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Ohman, M.D.</style></author><author><style face="normal" font="default" size="100%">Waide, R.B.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Lugo, A.E.</style></author><author><style face="normal" font="default" size="100%">Collins, Scott L.</style></author><author><style face="normal" font="default" size="100%">Driscoll, C.T.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Grove, J.M.</style></author><author><style face="normal" font="default" size="100%">Knapp, Alan K.</style></author><author><style face="normal" font="default" size="100%">Kratz, TK</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term trends in production, abundance, and richness of plants and animals</style></title><secondary-title><style 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face="normal" font="default" size="100%">Laney, C.M.</style></author><author><style face="normal" font="default" size="100%">Baker, K.S.</style></author><author><style face="normal" font="default" size="100%">Peters, Debra P.C.</style></author><author><style face="normal" font="default" size="100%">Ramsey, K.W.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yao, J</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Recommendations for data accessibility</style></title><secondary-title><style face="normal" font="default" size="100%">Long-term trends in ecological systems: A basis for understanding responses to global change</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">USDA Agricultural Research Service Publication</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">USDA</style></publisher><pub-location><style face="normal" font="default" size="100%">Washington, D.C.</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2011-86875</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%">Havstad, KM</style></author><author><style face="normal" font="default" size="100%">Joyce, L.</style></author><author><style face="normal" font="default" size="100%">Pieper, R.</style></author><author><style face="normal" font="default" size="100%">Svejcar, AJ</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Bartolome, J.</style></author><author><style face="normal" font="default" size="100%">Huntsinger, L.</style></author><author><style face="normal" font="default" size="100%">Peters, D.C.</style></author><author><style face="normal" font="default" size="100%">Allen-Diaz, B.</style></author><author><style face="normal" font="default" size="100%">Bestelmeyer, BT</style></author><author><style face="normal" font="default" size="100%">Briske, D.</style></author><author><style face="normal" font="default" size="100%">Brown, J.</style></author><author><style face="normal" font="default" size="100%">Brunson, M.</style></author><author><style face="normal" font="default" size="100%">Herrick, J. E.</style></author><author><style face="normal" font="default" size="100%">Johnson, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The western United States rangelands, a major resource</style></title><secondary-title><style face="normal" font="default" size="100%">Grassland, Quietness and Strength for a New American Agriculture</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/09-011.pdf</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rangeland is a type of land found predominantly in arid and semiarid regions, and managed as a natural ecosystem supporting vegetation of grasses, grass-like plants, forbs, or shrubs.  There are approximately 761 m ac of rangeland in the United States, about 31% of the total land area.  This land type is characterized by 4 features: 1) limited by water and nutrients, primarily nitrogen (N), 2) annual production is characterized by tremendous temporal and spatial variability, 3) a nested landscape of public and private ownership, and 4) throughout their history of use these lands have been uniquely coupled systems of both people and nature.  In the U.S. Department of Agriculture’s 1948 Yearbook of Agriculture, the chapter on rangelands focused on a description of these lands occurring by region across the western United States, and the principles, developed mostly in the early 20th century, to manage these lands to provide the provisioning services of food and fiber through livestock grazing.  In the last 60 years, these western rangelands have undergone a transformation as the U.S. population has grown to over 300 million and relocated to urban areas within the western and southwestern states.  This population dynamic, along with tremendous changes in agricultural production and a reduction in the population involved in agriculture have resulted in significant changes in the uses and emphases placed upon these western lands.  This land type is now often looked to provide a multitude of goods and services not only to rural populations, but also to tens of millions of people in large urban areas located within these rangelands.  In this chapter it is our intent to reflect on the extent and nature of this transformation over the last 60 years.  We start with a description of this human dynamic, and its sociological implications.  We describe the major regions of the western continental U.S., the focal point of U.S. rangelands.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2009-90132</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%">White, Ethan P.</style></author><author><style face="normal" font="default" size="100%">Steinbeck, John R.</style></author><author><style face="normal" font="default" size="100%">Waide, Robert B.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Adler, Peter B.</style></author><author><style face="normal" font="default" size="100%">Lauenroth, William K.</style></author><author><style face="normal" font="default" size="100%">Gill, Richard A.</style></author><author><style face="normal" font="default" size="100%">Greenberg, David</style></author><author><style face="normal" font="default" size="100%">Kaufman, Dawn M.</style></author><author><style face="normal" font="default" size="100%">Rassweiler, Andrew</style></author><author><style face="normal" font="default" size="100%">Rusak, James A.</style></author><author><style face="normal" font="default" size="100%">Smith, Melinda D.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Shachak, M.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">A comparison of the species-time relationship across ecosystems and taxonomic groups</style></title><secondary-title><style face="normal" font="default" size="100%">Oikos</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword><keyword><style  face="normal" font="default" size="100%">LUQ</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">doi:10.1111/j.0030-1299.2006.14223.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">112</style></volume><pages><style face="normal" font="default" size="100%">185-195</style></pages><isbn><style face="normal" font="default" size="100%">0030-1299</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The species/time relationship (STR) describes how the species richness of acommunity increases with the time span over which the community is observed. Thispattern has numerous implications for both theory and conservation in much the sameway as the species/area relationship (SAR). However, the STR has received much lessattention and to date only a handful of papers have been published on the pattern. Herewe gather together 984 community time-series, representing 15 study areas and ninetaxonomic groups, and evaluate their STRs in order to assess the generality of the STR,its consistency across ecosystems and taxonomic groups, its functional form, and itsrelationship to local species richness. In general, STRs were surprisingly similar acrossmajor taxonomic groups and ecosystem types. STRs tended to be well fit by bothpower and logarithmic functions, and power function exponents typically rangedbetween 0.2 and 0.4. Communities with high richness tended to have lower STRexponents, suggesting that factors increasing richness may simultaneously decreaseturnover in ecological systems. Our results suggest that the STR is as fundamental anecological pattern as the SAR, and raise questions about the general processesunderlying this pattern. They also highlight the dynamic nature of most speciesassemblages, and the need to incorporate time scale in both basic and applied researchon species richness patterns.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2006-90549</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%">Peters, D.C.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Huenneke, L.F.</style></author><author><style face="normal" font="default" size="100%">Havstad, KM</style></author><author><style face="normal" font="default" size="100%">Herrick, J. E.</style></author><author><style face="normal" font="default" size="100%">Rango, A</style></author><author><style face="normal" font="default" size="100%">Schlesinger, W.H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A Framework and Methods for Simplifying Complex Landscapes to Reduce Uncertainty in Predictions</style></title><secondary-title><style face="normal" font="default" size="100%">Scaling and Uncertainty Analysis in Ecology: Methods and Applications</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/06-051.pdf</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Springer, Dordrecht</style></publisher><pub-location><style face="normal" font="default" size="100%">The Netherlands</style></pub-location><pages><style face="normal" font="default" size="100%">131-146</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Extrapolation of information from sites to landscapes or regions is especially problematic in spatially and temporally heterogeneous ecosystems.  Although linear extrapolations are the easiest and most cost-effective, other approaches are necessary when spatial location and contagious or neighborhood processes are important.  Because landscape and regions consist of a mosaic of sites differing in spatial heterogeneity and degree of connectedness, we expect a combination of scaling approaches is needed to characterize these areas.  Our goal was to develop a conceptual framework and operational approach to simplifying complex landscapes in order to minimize uncertainty in predictions.  We illustrate our approach for arid and semiarid landscapes where spatial variation in carbon dynamics, in particular aboveground net primary production, is a timely and important problem.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2006-90553</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%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Peters, D. P. C.</style></author><author><style face="normal" font="default" size="100%">Havstad, KM</style></author><author><style face="normal" font="default" size="100%">Gibbens, R. P.</style></author><author><style face="normal" font="default" size="100%">Herrick, J. E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Multi-scale factors and long-term responses of Chihuahuan Desert grasses to drought</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%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/06-034.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">1217-1231</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Factors with variation at broad (e.g., climate) and fine scales (e.g., soil texture) that influence local processes at the plant scale (e.g., competition) have often been used to infer controls on spatial patterns and temporal trends in vegetation. However, these factors can be insufficient to explain spatial and temporal variation in grass cover for arid and semiarid grasslands during an extreme drought that promotes woody plant encroachment. Transport of materials among patches may also be important to this variation. We used long-term cover data (1915&amp;ndash;2001) combined with recently collected field data and spatial databases from a site in the northern Chihuahuan Desert to assess temporal trends in cover and the relative importance of factors at three scales (plant, patch, landscape unit) in explaining spatial variation in grass cover. We examined cover of five important grass species from two topographic positions before, during, and after the extreme drought of the 1950s. Our results show that dynamics before, during, and after the drought varied by species rather than by topographic position. Different factors were related to cover of each species in each time period. Factors at the landscape unit scale (rainfall, stocking rate) were related to grass cover in the pre- and post-drought periods whereas only the plant-scale factor of soil texture was significantly related to cover of two upland species during the drought. Patch-scale factors associated with the redistribution of water (microtopography) were important for different species in the pre- and post-drought period. Another patch-scale factor, distance from historic shrub populations, was important to the persistence of the dominant grass in uplands (Bouteloua eriopoda) through time. Our results suggest the importance of local processes during the drought, and transport processes before and after the drought with different relationships for different species. Disentangling the relative importance of factors at different spatial scales to spatial patterns and long-term trends in grass cover can provide new insights into the key processes driving these historic patterns, and can be used to improve forecasts of vegetation change in arid and semiarid areas.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2006-90561</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%">Peters, D. P. C.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Gosz, J. R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Woody Plant Invasion at a Semi-arid Transition Zone: Importance of Ecosystem Type to Colonization and Patch Expansion</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">JRN</style></keyword><keyword><style  face="normal" font="default" size="100%">SEV</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">bibliography/06-024.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">389-396</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Our objective was to evaluate how patterns in colonization and patch expansion of an invasive woody plant, Larrea tridentata (creosotebush) differ between two grassland ecosystems at a biome transition zone. We sampled frequency of occurrence, height, and surface area of saplings (n=134) and patches of adult plants (n=247) of creosotebush within a mosaic of ecosystems dominated either by the Chihuahuan Desert species, black grama, or the shortgrass steppe species, blue grama, located within 1 km of the creosotebush-dominated ecosystem. Distances between patches and patch area were used to estimate connectivity and propagule pressure. Sapling height and distance to the creosotebush dominated ecosystem were used to estimate patterns in dispersal. Our results show that creosotebush saplings (&lt;1%) and patches of adults (15%) occur less frequently in black grama than blue grama-dominated ecosystems. Propagule pressure did not differ with distance from the core creosotebush ecosystem. Evidence was found for both local and long distance dispersal. We conclude that spatial variation in creosotebush saplings and adults at this biome transition zone is related to the different susceptibilities to invasion by the two grassland ecosystems. The persistence of grasslands at this site despite region-wide expansion by creosotebush may be related to the spatial distribution of blue grama-dominated ecosystems that resist or deter invasion by this species.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2006-90479</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%">Peters, D.C.</style></author><author><style face="normal" font="default" size="100%">Yao, J</style></author><author><style face="normal" font="default" size="100%">Havstad, KM</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Insights to invasive species dynamics from desertification studies</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%">http://wssa.allenpress.com/pdfserv/i0890-037X-018-05-1221.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">1221-1225</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The objective of this paper is to provide insights into exotic and native invasive species dynamics using a conceptual model developed from the long history of research on native woody plant invasion into perennial grasslands.  We first describe our new conceptual model that focuses on landscape characteristics (spatial configuration and connectivity) interacting with environmental drivers and biotic processes across multiple scales.  We then provide support for the model using a long-term dataset from southern New Mexico.  Finally, we discuss new insights this model has to offer for understanding, predicting, and managing exotic invasive species dynamics.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2004-90747</style></accession-num></record></records></xml>