主要草原生态系统生产力对气候变化响应的模拟

Simulation on Productivity of Main Grassland Ecosystems Responding to Climate Change

利用历史气候数据(1961-2010年)和气候情景数据(1961-2100年)驱动CENTURY模型模拟高寒草甸、温性草甸草原、温性草原和温性荒漠4类主要草原生态系统的地上净初级生产力(ANPP),分析考虑和不考虑大气CO2浓度增加的直接效益(以下简称"CO2增益")未来气温和降水量变化对ANPP的影响。结果表明:(1)1961-2010年,高寒草甸的ANPP呈极显著增加趋势(P<0.01),与生长季内最低气温上升密切相关;温性草甸草原、温性草原和温性荒漠的ANPP变化趋势不显著,但年际波动较大,均与同期降水量具有极显著的正相关(P<0.01),而与同期气温的相关性较弱。(2)若不考虑大气CO2增益,在A2和B2情景下2020s(2011-2040年)、2050s(2041-2070年)、2080s(2071-2100年)时段该4类草原生态系统的ANPP相对于基准时段(1961-1990年)的平均增幅分别为4.9%、12.0%、18.6%和3.0%、6.6%、8.9%,其中温性草原的ANPP增幅最大,其次是温性荒漠,而温性草甸草原和高寒草甸的ANPP有增有减,变幅较小。(3)若考虑大气CO2增益,在A2和B2情景下2020s、2050s、2080s时段该4类草原生态系统的ANPP较不考虑大气CO2增益均有显著增加(P<0.05),平均增幅分别为20.0%、31.8%、45.6%和9.0%、13.7%、18.0%,其中温性草原的ANPP增幅最大,其次是高寒草甸和温性荒漠,而温性草甸草原的ANPP增幅稍小。

Based on the calibrated and validated CENTURY model, aboveground net primary production （ANPP） in alpine meadow （AM, Haibei alpine meadow ecosystem research station of CAS in Qinghai province ）, temperate meadow steppe （TM, Yaojingzi grassland reserves in Jilin province）, temperate steppe （TS, Inner Mongolia grassland ecosystem research station of CAS） and temperate desert （TD, Alashanzuo banner in Inner Mongolia autonomous region） were simulated by using observed climatic data （1961 -2010） and projected climatic data （1961 PRECIS model under A2 and B2 scenarios. Therefore, the effects of climate change on ANPP in four types -2100） by of grassland ecosystems were analyzed with or without considering the enhanced atmospheric CO2 concentration under A2 and B2 scenarios. The results indicated that ： （ 1 ） In the past 50 years, the trend of ANPP in AM ascended significantly （ P 〈 0. 01 ） mainly affected by minimum temperature increase, and each ANPP in other three types of grassland ecosystems showed large inter-annual variation with no significant trend. The positive correlation between ANPP and precipitation in TM, TS and TD were extremely significant （ P 〈 0. 01 ）, while the correlation between ANPP and temperature in TM, TS and TD were relatively weaker. （2） Without considering the enhanced atmospheric CO2 effect, the average changes of ANPP in four types of grassland ecosystems in 2020s, 2050s and 2080s compared to baseline （ 1961 - 1990） would increase by 4.9% , 12. 0%, 18.6% and 3.0% 6. 6%, 8.9% under A2 and B2 scenarios, respectively. The increase rate of ANPP is TS 〉 TD 〉 TM 〉 AM. （3） With considering the enhanced atmospheric CO2 effect, ANPP in four types of grassland ecosystems could increase significantly and the average changes of ANPP in 2020s, 2050s and 2080s would be 20.0% , 31.8% , 45.6% and 9.0% , 13.7% , 18.0% under A2 and B2 scenarios, respectively. The increase rate of ANPP is TS 〉 AM 〉 TD 〉 TM.