A new prefectural-level nature reserve, the Bulong Nature Reserve, was established in December 2008 in southern Yunnan, adjacent to the border with Myanmar, to protect its high species diversity and particular floristic composition from the great threat of expanding rubber plantations.Prof. ZHU Hua and his colleagues of Xishuangbanna Tropical Botanical Garden (XTBG) investigated the vegetation and flora of the Bulong Nature Reserve to inform its administration and management.

Bulong nature reserve has a mountainous topography, with the lowest elevation at 485 m on the Mekong River and the highest summit at 2,196.6 m. Three vegetation types in three altitudinal zones were recognized: a tropical seasonal rain forest below 1,100 m; a low montane evergreen broadleaved forest at 1100-1600m; and a montane rain forest above 1600m. A total of 1567 species of seed plants in 758 genera and 146 families were recorded from the nature reserve. The families with highest species richness were Fabaceae (108 species), Euphorbiaceae (79), Rubiaceae (79), Lauraceae (65), Orchidaceae (55), and Lamiaceae.

  In the flora of the Bulong Nature Reserve, tropical elements together make up 80% of the flora, and the Tropical Asia elements are 26% of the flora. Despite the high latitude and cool winters, therefore, the flora of the nature reserve is evidently tropical in nature and has a close affinity to the tropical Asian (Indo-Malaysia) flora.

Both the tree species diversities and the numbers of genera and familiesare higher in the lowlands and middle montane zones than in the lower montane. The lower diversity in the lower montane zone could reflect less precipitation and frequent fires in the historical past. The species compositions of samples within each altitudinal zone show greater horizontal turnover  (β diversity) in the lowlands.Conservation efforts should focus on the species-rich lowland and middle montane forests.

  For more information, please read “Vegetation, floristic composition and species diversity in a tropical mountain nature reserve in southern Yunnan, SW China, with implications for conservation” in Tropical Conservation Science.