国家自然科学基金41006502;国家科技部973全球变化项目课题2010CB951202;浙江省科技计划资助项目2012F20049;浙江省自然基金资助项目LY13E090001[Foundation:Natuaral Science Foundation of China,No.41006502;Minstry of Science and Techology of China,2010CB951202;Scienc and Techology Plan in Zhejiang Province,2012F20049;Natuaral Science Foundation of China,LY13E090001]