[Characteristics and disturbance status of gaps in subalpine fir forest in southeast Tibet].
Characteristics and disturbance status of gaps, including gap size, disturbance frequency, forming patterns of gaps, and quantity of the tree in gap, in subalpine fir forest in Southeast Tibet were studied. The results showed that expanded gaps accounted for 41.73% and canopy gaps accounted for 14.71% of land area in the forest. Averagely, 0.82% and 0.29% of forest area were transformed into expanded and canopy gaps every year. The velocity of gap forming was 0.31 ind.hm-2.yr-1. The disturbance cycle of gaps was 345 yr. Among 16 investigated gaps, there were 78 gap-markers in total, and there were averagely 4.88 trees in each gap. The main reasons of gap forming were gap-markers fallen as well as uprooted and withered, and their external force was strong wind. The possibility of gaps forming reached the maximum while the diameter of arbors was 40-60 cm and the high was 15-20 m in the main forest layer. Gaps were formed by many disturbances in different age in the subalpine fir forest in Southeast Tibet..
Luo
Daqing
D
Institute of Tibet Plateau Ecology, Linzhi 860000. dqluo0894@163.com
Guo
Quanshui
Q
Xue
Huiying
H
Bianbaduoji
D028202:Abies / Q000254:growth & development*; D017753:Ecosystem; D018609:Tibet; D014197:Trees