Modelling dynamic niche and community model by type-2 fuzzy set

Niche and community theory are the basis for much ecological research. The interrelationship between life and environment demands a dynamic niche model to assess where species habitats are preferential. In this paper, we propose a niche model with dynamic characteristics based on the “broadband” in type-2 fuzzy sets. The community model and its relatives, such as ecotone, similarity degree and separate degree of community are also established. Based on the proposed model, it is better to describe the dynamic processes between fundamental niche and realized niche, as well as inherent ecosystem uncertainties. Furthermore, the effect on community structure of the physical environment and of inter-specific competition can be identified. Simulation results indicate the niche could not only include the result by classic model, but also imply more information, i.e., the range of niche affected by environment. The model accurately locates the range distribution in natural secondary forests of Phellodendron amurense and Tilia amurensis.