本文由国家国际科技合作专项2015DFA90900、重庆市林业重点科技攻关项目渝林科研2015-6和中央财政林业科技推广示范项目渝林科推[2014-10]资助 This work was supported by the International Cooperation Program of Ministry of Science and Technology of China 2015DFA90900,the Key Forestry Science and Technology Project of Chongqing MunicipalityChongqing forest research 2015-6 and the Central Fiscal Demonstration Project on Forestry Science and Technology Extension Chongqing forest extension[2014-10].