title: [Dynamic changes of vegetation net primary productivity in permafrost zone of Northeast China in 1982-2009 in response to global change].
abstract: As one of the high-latitude cold regions, the permafrost zone of Northeast China (PZNC) is more sensitive to global change. Based on the AVHRR GIMMS NDVI and MODIS NDVI, and by using CASA model, this paper simulated the net primary productivity (NPP) in the PZNC from 1982 to 2009. In 1982-2009, the mean annual air temperature, annual solar radiation and sunshine duration, and atmospheric CO2 concentration and its annual increasing rate in the PZNC increased significantly while the annual precipitation had a significant decrease, and the annual NPP showed an up-and-down trend, with the turning point in 1998. The annual NPP had a high spatial heterogeneity, with an average of 623 g C X m(-2). Comparing with air temperature, the precipitation in growth season was the main factor affecting the NPP. Land use change altered land cover, and thus, the spatiotemporal characteristics of NPP. A significant positive correlation was observed between the NPP and atmospheric CO2 concentration. The impact of permafrost degradation on NPP differed with regional environment. The NPP had a significant positive correlation with the mean annual ground temperature, but a negative correlation with the annual maximum permafrost depth.
authors.affiliation: Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China. maodehua@gmail.com
authors.forename: De-Hua
authors.initials: DH
authors.lastname: Mao
authors.forename: Zong-Ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Ling
authors.initials: L
authors.lastname: Luo
authors.forename: Ji-Xing
authors.initials: JX
authors.lastname: Han
mesh_terms: D002681:China; D057231:Climate Change; D003081:Cold Climate; D017753:Ecosystem; D008962:Models, Theoretical; D063245:Plant Development; D006109:Poaceae / Q000254:growth & development*; D014197:Trees / Q000254:growth & development*