Swain, D.L., Hutchings, M.R. and Marion, G.
Ecological Modelling 203, 319-326.
||The importance of animal selection behaviour in determining equilibrium status of grazing systems has been much debated. Although changes in stocking density provides a mechanism for direct control of animal impact grazing behaviour is also responsible for influencing vegetation dynamics. A spatially explicit grazing model is used to explore the impact of search rate and search distance on spatial variance of sward structure. The model simulates the two stage grazing process in heterogeneous environments i.e. searching then biting. As search rate and search distance increase so the spatial variance of sward structure decreases. Changes in search rate have a greater impact on spatial variance than search distance. Search rate is more closely coupled with biting than search distance. The results demonstrate a positive relationship between behavioural parameters and spatial variance. The study concludes that variations in both search rate and search distance are responsible in determining a component of equilibrium status.