关键词: ecosystem services, Northeast China forest belt, land use optimization, ecosystem services tradeoff and synergy.

Abstract: Northeast forest belt is an important carrier of ecological security pattern of China. It is of great significance to optimize its ecological pattern for improving the ecosystem function and stability. In this study, we analyzed the spatial and temporal patterns of land use and ecosystem services, and identified the major driving factors. With the aim to improve the dominant ecological functions of the Northeast China forest belt, we coupled the driving mechanism of ecological services, and used a cellular automata model to optimize its land use pattern. The results showed that the effects of different driving factors on ecosystem services were significantly different. Habitat quality had the strongest correlation with land use (R=-0.420, P<0.05). Water supply was significantly affected by annual precipitation (R=0.602, P<0.05). Soil conservation was significantly affected by elevation (R=0.358, P<0.05). Water conservation was closely related to precipitation (R=0.760, P<0.05), while food supply was affected by elevation (R=-0.418, P<0.05), slope (R=-0.225, P<0.05) and temperature (R=0.306, P<0.05). The coniferous and broadleaved mixed forests were the most important for water conservation and habitat quality. Paddy field was more important for food production than  dry farmland. The results of land use optimization simulation showed that the proportion of ecological land (including forest, grassland, and wetland), productive land (paddy field and  dry farmland) and living land (construction land) was not significantly different from that before optimization. However, forests in Changbai Mountain and Lesser Khingan should be changed from deciduous broadleaved forest to coniferous and broadleaved mixed forest to improve water conservation and habitat quality. The Greater Khingan region should transform part of the deciduous broadleaved forest into wetlands to improve water conservation in the area. Under the condition of controlling the total amount of cultivated land without obvious change, increasing the proportion of paddy field in the intersection area between Lesser Khingan and Changbai Mountain and Sanjiang Plain can improve food supply service. In conclusion, this study could help optimize the ecological pattern of the study area without further aggravating the spatial contradiction between ecological land and other land use types, which provides a scientific basis for promoting the dominant ecological function of Northeast China forest belt and giving full expression of its barrier function.

Key words: 生态系统服务, 东北森林带, 土地利用优化, 生态系统服务权衡与协同