草地碳汇/源是植被生态系统中碳收支和碳平衡的一个重要内容，区分碳汇和碳源对气候变化的响应可为减源增汇提供科学依据。基于MODIS NPP数据和土壤呼吸模型量化了2001-2019年青藏高原草地净生态系统生产力(NEP)的时空变化和碳汇/源格局，利用通径分析方法分析了青藏高原气候变化对草地碳汇/源的影响。结果表明:青藏高原草地NEP呈现东高西低的分布格局，年平均值为54。41 g C m-2。草地整体上以碳汇功能为主。碳汇区面积约为72。26万km2，碳源区面积约为47。82万km2，净碳汇总量65。35 Tg C a-1。 近19年青藏高原草地NEP以增加趋势为主，青藏高原气候暖湿化趋势有利于草地NEP的增加，增强碳汇;而暖干化趋势对NEP 的影响在不同生态地理区差异较大。
Impacts of climate change on grassland carbon sink/source patterns in the Qinghai-Tibet Plateau
Grassland carbon sink/source is an important part of carbon budget and carbon balance in vegetation ecosystem.Distinguishing the response of carbon sink and carbon source to climate change can provide a scientific basis for reducing sources and increasing sinks.Based on MODIS NPP data and the soil respiration model,we quantified the spatial and temporal variability of Net Ecosystem Productivity(NEP)and carbon sink/source patterns in the Qinghai-Tibet Plateau(QTP)grassland ecosystem from 2001 to 2019,and analyzed the impact of climate change on grassland carbon sink/source using path analysis.The results show that the NEP in the grassland of the QTP presents a distribution pattern of higher in the east and lower in the west,with the av-erage annual NEP of 54.41 g C m-2.Most of the grassland area in the QTP has functioned as a car-bon sink since 2001.The areas of carbon sink are about 72.26×104 km2,with an average carbon sequestration of 79.61 Tg C a-1.The carbon source areas are about 47.82×104 km2,with an aver-age carbon release of 14.26 Tg C a-1.Over the past 19 years,the trend of NEP in grassland of the QTP has been increasing.The trend of warming and humidification in the QTP was conducive to the increase of grassland NEP and the enhancement of carbon sinks.However,the effects of warming and drying trends on NEP varied greatly in different eco-geographical region systems.
NETL
NSTL
万方数据
