Yu, D.Y.; Shi, P.J.; Han, G.Y.; Zhu, W.Q.; Du, S.Q.; Xun, B.

State Key Laboratory of Earth Surface Processes and Resource Ecology, Key Laboratory of Environment Change and Natural Disaster, MOE/Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China

Abstract: China has a long history of large-scale deforestation that has contributed to serious consequences such as frequent geological disaster, flood and soil erosion. It was only recently that forest management strategy shifted from the traditional harvesting orientation to a more balanced forest ecosystem management approach with a focus on conservation. To understand the effects of such a shift, on the forest dynamics especially since the implementation of Natural Forest protection Project (NFPP), this paper examined the case of Lushuihe region, a typical region of the northeast China forest zone. Land use and landscape pattern for the period of 1975-2007 were analyzed based on Landsat MSS and TM images. Net primary, productivity (NPP), estimated with the CASA productivity model, was used to assess the human impacts on the forest ecosystem function. The results showed a reversing trend of forest cover since 1988, from continuous decrease to rather rapid increase. From 1975 to 1988, due to reckless deforestation, the forest cover in the case region decreased about 10439.39 ha (8.54% of the study area). Forest cover of the region recovered from 77.68% in 1988 to 89.56% in 1999 and 92.33% in 2007. While the forest cover increased, landscape metrics indicate that human disturbance significantly altered the composition and structure of the forest landscape. NPP change indicated a continued decreasing trend until 2007, albeit at a slower pace since 1988. In 2007, while the decreasing trend of NPP was reversed, the forest structure was still inferior to that of 1975. Looking forward, diversifying and securing the livelihoods of the still growing local population that have been heavily dependent on the traditional forestry industry remain one of the key challenges as well as solutions for enhancing and managing the regional forest ecosystem structure and function in the region.

Keywords: Land use/Land cover; Landscape pattern; Net primary productivity; Deforestation; Natural forest protection project