Habitat characteristics and niche analysis of Calanthe sieboldii Decne. survival community

Calanthe sieboldii Decne. is included in the National Implementation Plan for Rescuing and Conserving China's Plant Species with Extremely Small Populations (PSESP), highlighting the urgent need for its rescue. To determine the habitat characteristics of C. sieboldii and the interspecific relationships among species within the C. sieboldii community, we conducted a comprehensive investigation of C. sieboldii distributed in Jingxian County of Anhui Province, China. Based on data from 22 quadrats in 18 sample plots, we analyzed the habitat conditions of the C. sieboldii community, and analyzed the niche characteristics of the main herbaceous species in the community using Levins' and Hurlbert's formulae for niche breadth and the similarity ratio of resources used for niche overlap. Results showed that:(1) C. sieboldii exhibited scattered distribution in Taoling village of Jingxian County, with most plants found in relatively open areas under steep cliffs near rivers with no direct sunlight; (2) C. sieboldii had an obvious advantage in the herb layer of the community. Niche overlaps existed among the main species in the herb layer, but the degree of overlap was low, interspecific competition was not intense, and environmental resources could be sufficiently shared by different species. The herb layer in the community was in a relatively stable condition.