Effects of anthropogenic revegetation on the water and carbon cycles of a desert steppe ecosystem
Effects of anthropogenic revegetation on the water and carbon cycles of a desert steppe ecosystem
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DOI：
10.1016/j.agrformet.2021.108339
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发表时间：
2021-01-29
影响因子：
6.2
通讯作者：
Bao, Gang
中科院分区：
文献类型：
--
作者：
Du, Lingtong;Zeng, Yijian;Bao, Gang
人为植被恢复是中国防治荒漠化的一项长期战略，它导致了荒漠草原灌木的入侵和区域显著的绿化。虽然人们已经认识到逆转荒漠化、防止侵蚀和提供生物量的好处，但对人为植被对陆地生态系统的关键过程水和碳循环的影响仍然知之甚少。以宁夏盐池县典型荒漠草原为研究对象，利用bime - bgc模型模拟草地和灌丛两种情景，评价了人为植被恢复对水碳循环的影响。利用2016 - 2019年的连续CO2和H2O通量测量来验证Biome-BGC的性能。结果表明：人为植被恢复显著增强了荒漠草原生态系统的碳循环，增加了生态系统的碳储量，使荒漠草原生态系统从弱碳源转变为强碳汇；与此同时，人为植被恢复严重增加了生态系统的耗水量，减少了土壤储水量。极端的后果将是，在降水作为唯一水源的情况下，水资源将超过生态系统的可持续极限。在国家和地方的生态恢复计划中，应该给予这些不良后果更多的关注。
The anthropogenic revegetation for combating desertification in China has been a long-term strategy that has induced shrub encroachment in desert steppe and regionally notable greening. Although the benefits of reversing desertification, preventing erosion, and providing biomass have been recognized, the effects of anthropogenic revegetation on water and carbon cycles, the critical process of terrestrial ecosystem, are still poorly understood. This study evaluates the effects of anthropogenic revegetation on water and carbon cycles in a typical desert steppe located in Yanchi County, Ningxia Province, Northwest China, by simulating two scenarios of grassland and shrub with the Biome-BGC model. Continuous CO2 and H2O flux measurements from 2016 to 2019 were used to validate the performance of Biome-BGC. Results showed that the anthropogenic revegetation significantly intensified the carbon cycle and increased carbon storages in the ecosystem and transformed the desert steppe ecosystem from a weak carbon source into a strong carbon sink. At the same time, the anthropogenic revegetation critically increased the water consumption of the ecosystem and decreased the soil water storage. The extreme consequence would be that the water resource will exceed the sustainable limit of ecosystems in the context of precipitation as the only water supply. Such undesired outcomes should be given more attention in state and local ecological restoration programs.