中国陆地生态系统对全球变化的敏感性研究

SENSITIVITY OF TERRESTRIAL ECOSYSTEM TO GLOBAL CHANGE IN CHINA

根据自然植被净第一性生产力综合模型和农业净第一性生产力模型计算了我国自然植被及农作物的净第一性生产力,结果表明:在所有可能的气候条件下,我国陆地生态系统的生产力表现出由东南向西北递减的趋势及明显的条带状分布,并在新疆地区形成明显的低值区。在年平均气温升高2℃且降水不变的情况下,湿润地区生产力增加幅度最大,约增加1～2tDW·hm^(-2)·a^(-1);在年平均气温升高2℃、年降水增加20％的情况下,干旱、半干旱地区生产力增加幅度最大,约增加0.5～3.0tDW·hm^(-2)·a^(-1);在年平均气温升高2℃、年降水减少20％的情况下,湿润地区生产力提高约0.5～1.0tDW·hm^(-2)·a^(-1),干旱、半干旱地区生产力降低约0.5～2.0tDW·hm^(-2)·a^(-1)。

Assessment of the sensitivity of natural and agricultural vegetation in China to global change based on the natural vegetation net primary productivity (NPP) model and the agricultural vegetation NPP model had revealed a decreasing trend from the southeast to the northwest in a ribbon shaped distribution for the terrestrial ecosystem NPP, where the center of low NPP was formed in Xinjiang area under all possible conditions of climate change. In China the productivity of the terrestrial ecosystem would increase by 1 to 2 t DW hm-2 a-1 in moist area where the temperature increased by 2C with no change of precipitation. It would increase by 0.5 to 3.0 t DW hm-2 a-1 especially in arid and semiarid areas where the temperature increased by 2C and precipitation increased by 20% ; and would increase by 0.5 to 1.0 t DW hm-2 a-1 in moist area, decreased 0.5 to 2.0 t DW hm-2 a-1 in arid and semiarid areas especially in the arid area where the temperature increased by 2C and precipitation decreased by 20%. The results indicated that water was a key factor to terrestrial ecosystem in China.