关键词: 呼伦贝尔, 净初级生产力, 空间格局, 动态变化

Abstract: The Hulunbeier region is an area very sensitive to global climate change. It is, therefore, of great scientific significance to study spatial and temporal distribution of vegetation NPP of that region. Based on the satellite remote sensing data and meteorological data available and with the aid of a modified light utilization rate model, analysis was made of effects of meteorological factors on the distribution in Hulunbeier. Results show that the average NPP per unit area of the past 29 years was the highest in the Daxinganling forest region, being mostly over 450 g•m^-2 and the lowest in the Hulunbeier Steppe, varying for years in the range of 0～350 g•m^-2 and moderate in other areas of Hulunbeier between the forest and the steppe, varying for years in the range of >350~450 g•m^-2. As affected by the warming and drying climate, the distribution of NPP at the pixel scale varied sharply from area to area in the region. With declining precipitation and rising temperature, the NPP per unit area of the Hulunbeier Steppe displayed a descending trend, which was getting more and more significant towards the west.With rising temperature, the NPP per unit area of the northern portion of the forest area tended to increase slightly, while that of the southern portion went the other way around, and that of the farming-pastoral ecotone to the east of the Daxinganling Mountains also showed a declining trend.

Key words: Hulunbeier, net primary productivity(NPP), spatial pattern, dynamic variation