2 Materials and methods

2.1 Study area

Hainan Island (E108°37′-111°03′, N18°10′-20°10) is situated in the southern part of China, on the northern edge of the tropics (Figure 1). It has a tropical monsoon climate and a mild climate with long summers and short winters (Zhang et al., 2022). The annual average temperature ranges from 22°C to 27°C, and the island has abundant water. Hainan Island is an important distribution area for China’s monsoon forests and tropical rainforests (Zhang et al., 2022). The main forest vegetation types in Hainan Island are tropical rainforest, evergreen broad-leaved forest, coniferous forest, and plantation forest. Hainan Province has the largest tropical rainforest in China, with rich flora and fauna resources, covering 42.5% of the total tropical area of the country (Li et al., 2022). The critical areas for biodiversity conservation in my country, ”National Of the 120 species of wild plants in extremely small populations identified in the Plan for the Rescue and Protection of WPESP (2011-2015). Hainan has 24 key protection targets. Yunnan and Hainan are critical areas for the protection of WPESP (Sun et al., 2022)