Alkali scrub communities are typically dominated by such shrubs as Atriplex lentiformis ssp. torreyi (Nevada saltbush), Chrysothamnus nauseosus (rabbitbrush), Sarcobatus vermiculatus (greasewood), and Suaeda moquinii (inkweed). Distichlis spicata (saltgrass) and Sporobolus airoides (sacaton) are often present in the understory. Alkali scrub communities occur where water tables are slightly lower (two-to-four meters deep) than necessary to sustain alkali meadows (Manning 1997). When alkali meadows are subject to the combined anthropogenic stresses of groundwater pumping and livestock grazing, the meadows may become vulnerable to invasion by shrubs and conversion to alkali shrub communities (Manning 1999). Alkali scrub communities also occur in abandoned agricultural fields and are often floristically depauperate, consisting, in extreme cases, of monocultures of Atriplex lentiformis ssp. torreyi. The spatial extent of alkali shrub communities appears to have increased greatly in conjunction with anthropogenic disturbance, just as the extent of alkali meadows has diminished. In many alkali scrub communities, clumps of dead sacaton can still be found under the shrub canopy, which suggests how recently the conversion from meadow to shrubland occurred.