Modelling patterns of defoliation by grazing animals in rangelands.
Abstract
Techniques and models for identifying the distribution of grazing by domestic animals in large (>100 km2) rangeland paddocks in arid central Australia are described, and the relationship between grazing distribution and the characteristics of the vegetation cover is examined. Models of grazing distribution and resultant defoliation through time used the inverse Gaussian distribution function. Additional model components described the effects of natural decline in cover over time and the effect of past grazing on the spatial distribution of palatable species. Models were calibrated using remotely sensed vegetation cover data derived from Landsat MSS and closely reflected observed distribution of cattle in studies in central Australia. Fitted models showed systematic variations with observed plant species composition and the amount of forage present.