Huo Xiaopeng1,2,Li Xianwei1,Zhang Jian1,Zhang Xinghua3/sup>,Dai Jie1,Zhang Lianghui1
1.Provincial Key Laboratory of Ecological Forestry Engineering,Sichuan Agricultural University,625014,Ya'an,Sichuan;2.Southwest Oil & Gasfield Company Safety,Environment & Technology Supervision Research Institute,610213,Chengdu;3.Jintang County of Forestry and Garden Administration Bureau,610400,Jintang, Sichuan: China