英文摘要: |
Temporal dynamics in aboveground net primary productivity (ANPP) are significant for environmental protection and economic development in the Mongolian Plateau grasslands (MPGs). Climate control of ANPP's temporal variations has intensified in response to local meteorological conditions, while the contributions of large-scale atmospheric circulations to ANPP variations are poorly understood in the MPGs. First, we explored the temporal dynamics in annual ANPP, and then, we analyzed correlations among annual ANPP, local meteorological variables, and three different teleconnections during 1982-2015 in this study. Our analytical results indicated that (a) ANPP exhibited an increasing trend during the entire study period. However, the increasing trend did not persist, and two reversals occurred in 1998 and 2007. (b) ANPP variations were primarily influenced by summer precipitation in most regions and by summer precipitation and temperature together in other regions of the MPGs. (c) The Atlantic Multidecadal Oscillation (AMO) in winter negatively dominated annual ANPP variations by influencing summer precipitation and summer temperature in central Mongolia. The North Atlantic Oscillation (NAO) in winter exerted strong positive impacts on ANPP variations by influencing summer precipitation in Inner Mongolia, China. The East Atlantic Western Russia (EAWR) in spring controlled annual ANPP variations by influencing summer precipitation in western and eastern Mongolia. (d) The winter AMO, winter NAO and spring EAWR significantly dominated the annual ANPP variations in 49.78% of the MPGs, with values of 18.90, 9.81 and 21.07%, respectively. (e) Reversals of the winter AMO, winter NAO and spring EAWR between negative and positive phases resulted in two reversals of ANPP trends. This study will improve our understanding of the role of large-scale atmospheric circulations in regulating ANPP variations and will be valuable in guiding the development of grazing land management in Mongolia and Inner Mongolia, China. |