近56a蒙古高原草原地上净初级生产力变化

Change of above ground net primary productivity of grassland over the Mongolian Plateau in recent 56 years

草原生产力及其对气候变化的响应是全球变化研究的热点。利用ArcGIS插值技术,将蒙古高原32个气象站点数据插值成1°×1°的格点数据,然后利用CENTURY模型模拟了蒙古高原1961-2016年草原地上净初级生产力(ANPP)时空分布特征。结果表明:(1) CENTURY模型模拟的蒙古高原草原ANPP时空分布能够很好地反映该区域草原生产力的变化,草原ANPP分布由北向南,由东向西逐渐减少。(2)草甸草原和典型草原单产均呈波动下降趋势,草甸草原下降速率较大,荒漠草原单产呈波动上升趋势,草原总产以典型草原最大,荒漠草原面积虽然最大,但总产最低。(3)降水对草原生产力起主导作用,湿期会有荒漠草原→典型草原→草甸草原的转化,而干期的转化过程正好相反。从暖湿期→冷干期转换时,蒙古草原总产下降幅度最大,相反,则增产幅度最大。

Study of the grassland productivity and its response to the climate change has been an important aspect of the global change research.By using the ArcGIS interpolation technique,the observed data from 32 meteorological stations in the Mongolian Plateau are interpolated into the 1°×1° grid data,and then the spatiotemporal distribution characteristics of the above ground net primary productivity(ANPP) of the vegetation over the Mongolian Plateau from 1961 to 2016 are simulated by the CENTURY model.The results are shown as follows:(1) The spatial and temporal distribution of the ANPP simulated by the CENTURY model can well reflect the change of the grassland productivity in the Mongolian prairie,and the distribution of the ANPP in grasslands changed from north to south gradually from east to west.(2) The yields of meadow steppe and typical steppe are decreasing over time and the decrease rate of meadow steppe is higher,and the yields of desert steppe is rising over time.The largest total yields are in the typical steppe,and the lowest total yields are in the desert steppe which has the largest area.(3)The precipitation is the key factor for the grassland productivity.In the wet-period,there exists the transformation of desert steppe→typical steppe→meadow steppe,while the process of dry-period conversion is the opposite.The total yields of Mongolian steppe have the largest decrease when it is changed from the warm-wet period to the dry-cold period. In contrast,the total yields have the largest increase when it changed from dry-cold to warm-wet.