Distribution characteristics of national key protected wild plants in Hainan Province and the vegetation types underlying them

In order to reveal the distribution and habitat characteristics of national key protected wild plants in Hainan Province, we studied the distribution characteristics and vegetation types of national key protected wild plants in Hainan Province by selecting national key protected wild plants, based on the 2021 edition of The List of National Key Protected Wild Plants through the methods such as data reduction and field surveys. The results were as follows:(1)There were a total of 53 families, 83 genera and 173 species of national key protected wild plants in Hainan Province, ranking fifth in the number of species and first in the density of species in China(based on the current data base of wild).(2)All 19 counties and municipalities in Hainan Province had national key protected wild plants, and the number of species in the central and the south of the cities/counties is much larger than that in the north, with the largest species richness in Changjiang Li Autonomous County(75 species), and the highest species density in Lingshui Li Autonomous County(0.604 5 ind.·km-2); the number of species of national key protected wild plants was distributed in nine gradients(with a gradient value of 200 m)from 0 m to 1 867 m above sea level, and there were a trend of slightly decreased-very rapidly increased-slowly decreased, with the highest number of species distributed in the elevation band. When 800 m ≤ Altitude < 1 000 m and 1 000 m ≤ Altitude < 1 200 m, there was 81 national key protected wild plant species, while only 9 species in the segment 1 600 m ≤ Altitude < 1 867 m.(3)The habitats of national key protected wild plants in Hainan Province were complexed, relied on a total of 11 vegetation types, among which the lowland rainforest had the highest species richness(114 species), followed by mountain rainforest(105 species)and the semi-mangrove forest(1 species); and the most severely externally disturbed is freshwater wet grassland, followed by lowland rainforest, and the least is montane cloud forest. The results of the study provide the scientific reference for the conservation and utilization of national key protected wild plants in Hainan Province.