The cover of Bouteloua eriopoda was negatively correlated with that of mesa dropseed Sporobolus flexuosus (r = -0.673, n = 10, P = 0.0331).
This was characterized by a decrease of perennial grasses, particularly the dominant black grama (Bouteloua eriopoda) although there was no detectable increase in the perennial shrubs.
This pattern did not appear in sites dominated by the shorter lived species, Bouteloua eriopoda
The more densely vegetated sandy loam site supported scattered longleaf yucca (Yucca elata), Mormon tea (Ephedra trifurca), black grama (Bouteloua eriopoda), sand dropseed (Sporobolus cryptandrus) and blue grama (Bouteloua gracilis).
The sandy loam site is characterized by widely scattered longleaf yucca (Yucca elata) and Mormon tea (Ephedra trifurca); black grama (Bouteloua eriopoda) dominates the herbaceous understory, with lesser amounts of sand dropseed (Sporobolus cryptandrus) and blue grama (Bouteloua gracilis).
The vegetation is Chihuahuan desert scrub, which had replaced a predominantly Bouteloua eriopoda
Common grasses were sand bluestem (Andropogon hallii), little bluestem (Schizachyrium scoparium), blue grama (Bouteloua gracilis), black grama (Bouteloua eriopoda
), sideoats grama (Bouteloua curtipendula), sand dropseed (Sporobolus cryptandrus), and purple threeawn (Aristida purpurea).
We sampled grassland and shrubland sites at the Sevilleta National Wildlife Refuge (n = 1 each) and the Jornada Experimental Range (n = 2 each) in the Chihuahuan Desert of New Mexico, where various desert shrubs, including Larrea tridentata, have invaded perennial grasslands, dominated by Bouteloua eriopoda
, during the last century (Buffington and Herbel 1965).
The vegetation in the study area was typical Chihuahuan Desert scrubland, dominated by creosote bush (Larrea tridentata), lechuguilla (Agave lechuguilla), ocotillo (Fouquieria splendens), catclaw (Acacia greggii), white thorn acacia (Acacia constricta), honey mesquite (Prosopis glandulosa), and Eve's needle (Yucca faxoniana), as well as grasses represented by tobosa grass (Hilaria mutica) and black gramma (Bouteloua eriopoda
(in press) showed differences in plant-associated soil heterogeneity, apparently determined by the life-span of the plant, with the shorter-lived plant, Bouteloua eriopoda
, having less between vs.
Greatest percentages for total cover in 2005 and 2006 were on Green Gulch 2, which was comprised of Lehmann lovegrass (Eragrostis lehmanniana), sotol (Dasylirion leiophyllum), whitethorn acacia (Acacia constricta), and black grama (Bouteloua eriopoda
Natural vegetation in the area is a grama-tobosa shrubsteppe dominated by black grama (Bouteloua eriopoda
), tobosa (Hilaria mutica), and creosotebush (Larrea divaricata; Kuchler, 1964).