Yunnan of southwestern China is extremely diverse in habitat and topography. It supports an extremely rich biodiversity and various vegetation types dominated by evergreen broad-leaved forest.
The evergreen broad-leaved forest mainly includes the monsoon evergreen broad-leaved forest on tropical mountains in southern Yunnan, the semi-wet evergreen broad-leaved forest mainly on plateaus, and the mid-montane wet evergreen broad-leaved forest on upper mountains in central and northern Yunnan.
In a recent issue of Botanical Review, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) called for giving high conservation values to the evergreen broad-leaved forests due to their uniqueness and abundance Chinese endemic species, or due to heavy human disturbance.
The researchers established six 1-ha sampling plots, representing the three evergreen broad-leaved forest types, to investigate floristic composition, species diversity, physiognomy and floristic variation with geography.
The researchers found that the three evergreen broad-leaved forests of Yunnan are generally different in distribution, habitat and floristic composition, although they are characterized by the dominant species of the families Fagaceae, Theaceae and Lauraceae, and evergreen broad-leaved trees.
The lower montane evergreen broad-leaved forest (LMEB) in southern Yunnan, which is dominated by tropical species, especially tropical Asian elements, is a type of tropical lower montane forest of southeast Asia. The semi-wet evergreen broad-leaved forest (SWEB) and the upper montane evergreen broad-leaved forest (UMEB), which have the highest ratio of Sino-Himalayan and Chinese endemic species in their floristic compositions, are unique in southwestern China. The UMEB has evolved to a cloudy forest on upper wet mountains.
“The SWEB and the UMEB should be given high conservation values due to their abundant Chinese and Yunnan endemic species,” said Prof. ZHU Hua, principal investigator of the study.
“The highest protection attention should be especially given to the semi-wet evergreen broad-leaved forest, because most remnants of the forest found outside of nature reserves are lost due to heavy human disturbance”, said Prof. ZHU.
ZHU Hua Ph.D
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China