Basal cover (percentage) of black grama (Bouteloua eriopoda), a dominant upland perennial grass in the Chihuahuan Desert, on four individual 1-square-meter quadrats, each representing a class of quadrats with different dynamics. These findings indicate that drought alone cannot explain temporal variation in grass loss across the Jornada Basin. Black grama went locally extinct on most quadrats (64%) either during (b) or shortly after (c) the 1950s drought. However, this species went locally extinct on 21% of research quadrats before the drought (a), and persists to the present day on 15% of the quadrats (d). Grass persistence was related to landscape context: Quadrats located farther from historic shrublands persisted longer than quadrats adjacent to shrub-lands (Yao et al. 2006).
Peters et al. 2006. Disentangling complex landscapes: new insights into arid and semiarid system dynamics. BioScience. 56:491-501.