2 Methods
2.1 Study area
Our study area consists of two nature reserves (Heizhugou Nature
Reserve, 28°40′-29°10′N, 102°50′-103°10′, and Meigu Dafengding Nature
Reserve,
28°30′-28°50′
N, 102°52′-103°20′E) in Mt. Liangshan (Fig. 1). This area is within a
global biodiversity hotspot (i.e. the Hengduan Mountains, Mittermeier et
al., 2005) and features a subtropical monsoon humid climate with
elevations ranging
from
1054–4288 m.
Our study region has large areas of primary, secondary and plantation
forests. Primary forests are scattered along the mountain ridges in the
Heizhugou Nature Reserve and in the northeastern core area of
the
Meigu Dafengding Nature Reserve. Secondary forests, consisting mainly of
second-growth broad-leaved trees, were allowed to recover naturally.
Tree species of Pinaceae, Fagaceae and Cornaceae are dominant in the
old-growth and secondary forests. Plantation forests were first planted
on the land after large-scale deforestation during the 1970s and are now
distributed throughout the Meigu Dafengding Nature Reserve and Heizhugou
Nature Reserve. The predominant plant species in the plantation forests
are Cunninghamia lanceolata, Picea asperata and Abies
fabri .