In 1 ha sampling plot for all life forms, 360 vascular plant species were identified in the LMEB, and 174 species in the SWEB, and 144 species in the SWEB on limestone, as well as 166 species in the UMEB.
The LMEB is extremely rieh in species, having 138 and 104 tree species with dbh > 5 cm recorded from the two 1-ha plots respectively, while 53 tree species recorded in the SWEB and 40 tree species in the SWEB on limestone, as well as 41 and 45 tree species recorded from UMEB in 1-ha plots respectively.
However, the LMEB is overwhelmingly dominated by a single tree species but have more rare species presented, while the UMEB is co-dominated by several species and have less rare species presented.
The UMEB has the highest proportion of mesophanerophytes, and conspicuously more epiphytes, while the SWEB on limestone has more hemicryptophytes and lianas.
The UMEB has fewer entire leaved species than the other two forest types.
Excluding ferns, 329 seed plant species in LMEB, 164 species in SWEB, 129 species in SWEB on limestone, and 142 species in UMEB, are analyzed for biogeographical attributes based on Wu's works (Wu, 1991; Wu et al., 2006) (see the Methods section).
The upper montane evergreen broad-leaved forest (UMEB) is also dominated by Fagaceae, Lauraceae and Theaceae species.
The SWEB and the UMEB have a subtropical distribution, similar species diversity and temperate floristic elements making up the majority of their flora, in which Chinese endemic and Sino-Himalayan species are dominant.
In summary, the LMEB, with physiognomic and floristic similarities to the lower montane evergreen broad-leaved forest in mainland southeast Asia, is part of the later; the SWEB and UMEB, which have the highest ratio of Sino-Himalayan and Chinese endemic species in their floristic compositions, are unique in southwestern China, although the UMEB has similar physiognomic features to the upper montane forest in tropical Asia.
The SWEB and the UMEB, dominated by species endemic to China and Sino-Himalayan species, are subtropical forests unique in southwestern China, but the UMEB has evolved to a cloudy forest on upper wet mountains.
LMEB: lower montane evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest.