Title | Does livestock grazing influence spatial patterns of woody plant proliferation? |
Publication Type | Conference Paper |
Year of Publication | 2009 |
Authors | Browning DM, Archer SR, Franklin J, Guertin D.P |
Conference Name | Ecological Society of America Abstracts |
Date Published | August 2009 |
ARIS Log Number | 244074 |
Keywords | erosion, grasslands, nutrient, savannas, spatial pattern |
Abstract | Patterns of woody plant proliferation in grasslands and savannas influence rates of erosion, spread of disturbance, and nutrient pools. Spatial pattern is the outcome of plant dispersal, recruitment, competition/facilitation, and disturbance. We quantified effects of livestock grazing, a widely cited driver of shrub encroachment, on the spatial patterns of velvet mesquite (Prosopis velutina) distribution and recruitment in southeastern Arizona. Field surveys of plant canopy size and location spanning 74 years (1932, 1948, and 2006) were conducted on areas grazed by livestock since the late 1800s and on areas protected from livestock since 1932. Point pattern analysis and Moran’s I were used to quantify changes in distribution and spatial autocorrelation over time. |