内蒙古锡林河流域羊草草原净初级生产力及其对全球气候变化的响应

Net primary productivity of Leymus chinensis steppe in Xilin River basin of Inner Mongolia and its responses to global climate change.

利用CENTURY模型对内蒙古锡林河流域羊草草原在未来气候变化以及大气CO2浓度增高条件下的年地上净初级生产力（annual aboveground net primary productivity，ANPP）动态进行了模拟研究.结果表明：CENTURY模型可以较好地预测ANPP的变化.进一步的情景模拟发现，虽然全球气候变化所引起的温度和降水改变、以及大气CO2浓度升高都会影响ANPP，但降水是关键的影响因子.多个全球气候模型（GCM） 预测该地区未来降水量会减少，故可能导致其ANPP降低，但在以下气候变化情景下研究区ANPP可能会升高：1）CO2浓度倍增，温度升高2 ℃，降水保持不变或增加10%～20%；2）CO2浓度保持不变，温度升高2 ℃，降水增加20%.气候变化将对内蒙古锡林河流域羊草草原产生显著影响.

CENTURY model was utilized to simulate the annual aboveground net primary production （ANPP） of Leymus chinensis steppe, a dominant community type in Xilin River basin of Inner Mongolia steppe region. The results showed that the model performed reasonably well in predicting the dynamics of the ANPP. The scenario-based simulations indicated that though the variations of air temperature and precipitation due to global climate change as well as the elevated COe would significandy affect the dynamics of the ANPP, precipitation was the key affecting factor. Several GCM models-had predicted that the precipitation in this region would decrease in the future, and consequently, it was likely that the ANPP would also decrease. Nevertheless, the simulation results showed that while the ANPP decreased in most climate change scenarios, it might also increase in the following climate change scenarios： 1 ） if the atmospheric CO2 concentration was doubled, air temperature was increased by 2 ℃, and precipitation was kept unchanged or increased by 10%- 20%, and 2） if the atmospheric CO2 concentration was kept unchanged, air temperature was increased by 2 ℃, and precipitation was increased by 20%. Overall, it was evident that climate change would have significant effects on the steppe in Xilin River basin of Inner Mongolia.