Native grasses interact spatially with themselves and their environment and can therefore be thought of as a system of dependent random variables. One method of modeling the spatial dependence of a multi-species population is a Gibbsian pairwise potential model. Since natural selection operates at the level of individual plants, the information obtained from such a model should provide a greate...

rots (Great Plains); seedling blight (Great Plains). Indian ricegrass {Oryzopsis hymenoides) : Seedling blight (far West) ; common root rot and crown rot (far West) ; rhizoctonia rot (scattered) ; snow molds (Pacific Northwest); seed rots (general); root necrosis and crown rots (far West). Kentucky bluegrass {Poa pratensis): Dollar spot (Northeast) ; brown patch (general); foot rot, Helminthosp...

The genus Nassella, as currently circumscribed, includes 116–117 American species. It is characterized by florets with a strongly convolute lemma, a conspicuous or inconspicuous crown, and a short palea. Using 53 species of Nassella and 22 outgroup species we conducted phylogenetic analyses to test the monophyly of Nassella and relationships among species. Two plastid (trnT-trnL and rpl32-trnL)...

Paleoecological sources indicate that the location and extent of Sierra Nevada rangelands have varied significantly during the last 20,000 years. Modern vegetative associations are recent, with montane wet meadows appearing during the last 3,000 years. A late Pleistocene sagebrush grassland existed where montane and subalpine forests occur today. In the central Sierra a pattern of deglaciation ...