Fuzzy set ordination analysis of survival communities for an endangered medicinal plant species, Phellodendron amurense

Fuzzy set ordination is based on fuzzy mathematical theory and is attractive for ecologists for it directly incorporates the environmental gradients into the calculation of ordination scores. Fuzzy set ordination was applied to study ecological relations of survival communities for an endangered medicinal tree species, Phellodendron amurense, in the Xiaolongmen Forest Park, Beijing. The data sets consist of abundance values of 89 plant species and 6 environmental variables in 25 quadrats. The results showed that fuzzy set ordination successfully displayed quadrats in species space related to environmental gradients. The distribution of quadrats and community types on FSO ordination plot was fully interpreted. Altitude and litter thickness were key factors influencing community composition and structure. These relationships must be considered in conservation of P. amurense populations and communities.