Abstract:

Aims Landslide mass is a widely existing habitat type in the Minshan Mountains, but insufficient attention has been drawn to its importance in biodiversity research and protection. Orchid species are abundant in the landslide masses of the Wanglang National Nature Reserve, especially in the Baishagou landslide mass. By studying the spatial distribution pattern of orchids in the Baishagou landslide mass, we aimed to infer the approximate distribution pattern of orchids in the landslide mass of the Minshan Mountains and provide guidance for the protection of orchids in this area.

Methods We collected data from 186 quadrats belonging to 4 transects in the Baishagou landslide mass, and conducted interspecific association, correlation analysis, detrended correspondence analysis (DCA), and two-way indicator species analysis (TWINSPAN).

Results The results indicated that the herb community of the Baishagou landslide mass is primarily affected by environmental factors, and the competition among species is relatively weak. Canopy closure and water erosion both play important roles on the distribution of orchids in landslide masses. Landslide masses can be divided into three types: landslide-forest edge habitat (Type 1), landslide habitat (Type 2) and high canopy closure landslide habitat (Type 3). Adaptive differentiation has occurred between orchid species from Type 1 and Type 3.

Conclusion We suggest implementing protection points to monitor the richness of orchid distribution. In addition, detailed investigations should be carried out on other landslide masses which formed at different points in time and with different soil substrates to find out the distribution pattern of orchid species in the Wanglang National Nature Reserve, or even the entire Minshan area.

Key words: landslide mass, orchid, spatial distribution pattern, Giant Panda National Park