Abstract:

Aims: Hainan is rich in tropical bryophytes, of which as many as 29 species are known to be threatened. But due to the lack of attention and priority for the past time, conservation efforts need to be advanced. The study was to propose the conservation priority areas and highlight key areas for threatened bryophytes in Hainan, providing a scientific basis for bryophyte protection.

Method: In the present study, the maximum entropy (MaxEnt) model was used to simulate the suitable habitats of 27 threatened bryophytes in Hainan, and suitable habitats were identified and classified.

Results: The suitable areas and distribution patterns of selected bryophytes varied greatly. According to the proportion of suitable threatened bryophyte species richness (SR) to peak richness (40% < SR ≤ 60%, 60% < SR ≤ 80% and SR > 80%), the suitable habitat hotspots were divided into three levels: (1) The “relative” hotspot area, the richness of threatened bryophytes ranged from 11 to 15, was the largest, approximately 2,527.2 km². (2) The “significant” hotspot area, whose richness ranged from 16 to 20, was ca. 2,503.2 km². (3) The “extreme” hotspot area was the smallest, about 259.8 km², with species richness ranging from 21 to 25. Hotspots at all levels were mainly distributed in National Park of Hainan Tropical Rainforest, especially the “extreme” hotspots, which were typically distributed in the tropical cloud forests with an altitude of about 1,100 m (-1,300 m) above sea level, belonging to the core areas of National Park of Hainan Tropical Rainforest. Among the environmental variables tested, the mean diurnal range (Bio2) contributed the most to 11 bryophytes (46.2%-91.3%), and the temperature annual range (Bio7) contributed the most to 8 bryophytes (31.9%-82.2%), which significantly affected the distribution of threatened bryophytes in Hainan.

Suggestions: Suggestions for the protection of threatened bryophytes in Hainan are as follows: (1) Background surveys of bryophytes in Hainan are required to obtain distribution information and dynamic changes of threatened bryophytes. (2) Adjust the threat levels of some bryophyte species and place threatened bryophytes in the wild plant protection list of Hainan Province. (3) Protect the cloud forest regions and classify them as key areas in National Park of Hainan Tropical Rainforest. (4) Strengthen the monitoring of vascular plants in suitable hotspots. (5) Classify the hotspots outside the national park as ecological restoration areas, as well as strengthen the scientific research on secondary forest and plantation ecology and bryophyte community restoration of all hotspots.

Key words: threatened bryophytes, suitable habitat, maximum entropy (MaxEnt) model, environmental variables, tropical cloud forest, national park