| 英文摘要： |
Earth's cryosphere and biosphere are extremely sensitive to climate changes, and transitions in states could alter the carbon emission rate to the atmosphere. However, little is known about the climate sensitivities of frozen soil and vegetation production. Moreover, how does climate heterogeneity control the spatial patterns of such sensitivities, and influence regional vulnerability of both frozen soil and vegetation production? Such questions are critical to be answered. We compiled long-time-series dataset including frozen soil depth (FD), normalized difference vegetation index (NDVI), and temperature and precipitation across Tibetan Plateau to quantify their sensitivities. Results reveal large spatial heterogeneity in FD and NDVI sensitivities. Precipitation alleviated FD sensitivities to warming in the cold northeast zone but accelerated FD sensitivities to precipitation in the warm south and southeast. Meanwhile, the positive warming effect on the NDVI was largely offset by slow increase of precipitation. Areas with high FD decreasing rate were found in northeast, inland, and south and southeast zones. Predominate area across the nine eco-regions are characterized as medium FD decreasing rate, and are synchronized with positive NDVI response in inland and west Himalayas, but negative in northeast and south and southeast. Precipitation restriction on NDVI would be pronounced in moist south and southeast. Our study provides new information that makes a much-needed contribution to advancing our understandings of the effects of global climate change on cryosphere and biosphere, which has important implications for global climate and our ability to predict, and therefore prepare for, future global climatic changes. Our attempt confirms that the method we used could be used to identify climate sensitivity of permafrost based on substantial observation data on active layer dynamics in future. |
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