Analyzing the spatial heterogeneity of number of plant individuals in grassland community by using power law model

Spatial pattern of grassland community affects ecological processes, and the number of plant individuals is important to evaluate community dynamics as the fundamental ecological parameter of plant species, but so far few studies have dealt with spatial pattern of the number of plant individuals in grassland community. The research we present here explores whether the power law model can be used to evaluate spatial heterogeneity of the number of plant individuals of species in grassland community. As reference data, surveys of individuals were conducted on a natural grassland and a weed community, following random sampling method using 100 0.5 m × 0.5 m quadrats. We recorded the number of plant individuals of each species occurring in each quadrat. Our results show that (1) the power law model fits well to the spatial pattern of number of plant individuals, (2) the power law model can be applied to evaluate the spatial pattern of number of plant individuals in grassland community, and (3) spatial heterogeneity index value (δ) was positively associated with the average number of plant individuals (m) of species. Our research provides a new application of the power law model to study spatial heterogeneity of grassland community.