Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains;
Ministry of Education;
School of Geographical Sciences;
Northeast Normal University;
Changchun 130024;
China;
Centers for Global Environmental Research;
National Institute for Environmental Studies;
Tsukuba 305-8555;
Japan;
vegetation phenology; permafrost; Moderate Resolution Imaging Spectrometer(MODIS); solar-induced chlorophyll fluorescence(SIF); northeastern China;