Spatial pattern gradient analysis of a transect in a hilly urban area in China from the perspective of transportation corridor sprawl STUDIES ON KERNEL DENSITY ESTIMATION OF SPECIES ABUNDANCE DISTRIBUTION IN TWO COMMUNITIES OF RARE AND ENDANGERED PLANTS Evaluation and simulation of historical range of variability of forest landscape pattern in Huzhong area Stand density estimation based on the measurement of spatial structure. Simulating Diameter Structure:A Comparison of Nonparametric Kernel Method,Histogram Method and Diameter List Method Type of Distribution and Method of Density Estimation for Pantana phyllotachysae