Pollen reconstructed Holocene vegetation response to climate change and human activity in a semi-arid mountain area of north China
Pollen reconstructed Holocene vegetation response to climate change and human activity in a semi-arid mountain area of north China
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DOI：
10.1016/j.catena.2020.104878
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发表时间：
2020-12
期刊：
影响因子：
6.2
通讯作者：
Zijuan Yong;Wei Wang;Dongxue Chen;Lina Liu;Yuzheng Ma;Jiang He
中科院分区：
文献类型：
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作者：
Zijuan Yong;Wei Wang;Dongxue Chen;Lina Liu;Yuzheng Ma;Jiang He
了解全新世植被的响应机制，将有助于预测未来的植被动态在中国北方半干旱山区。本文以中国北方半干旱山区的一个花粉记录为研究对象，对花粉记录与影响因子之间的关系进行了统计分析，以期探索潜在的植被强迫和响应机制。结果表明，在6000 cal以前，高海拔的冷性落叶林和中低海拔的温带落叶林对温度的响应较为敏感。yr BP，但对夏季风（SM）不敏感。从6000口径开始。年BP时，CDF和TDF对SM的反应敏感，而对温度的反应不敏感。因此，响应机制的转变可以放置在6000 cal。年BP，这恰好与森林扩张转变为森林砍伐的时间相一致。在全新世早期，对SM的不敏感的反应可能是由于植被的海拔运动，地形障碍的森林从避难所迁移，和/或地形相关的高阻力和恢复力的山地森林。CDF和TDF对6000 cal.年BP主要是由SM持续减弱引起的累积水分亏缺造成的。直到几个世纪以前，人类活动对山地森林的影响很小。全新世早中期山地森林对气候变暖的响应可以为未来气候变暖的森林动态预测提供类比。
Understanding Holocene vegetation response regimes will improve predictions of future vegetation dynamics in mountain areas of semi-arid north China. In this paper, we statistically analyzed the relationship between a pollen record in a mountain area of semi-arid north China and influencing variables independent of pollen data, in the hope that potential vegetation forcing and response regimes can be explored. Our result suggests that the cool deciduous forest (CDF) at high elevation and the temperate deciduous forest (TDF) at middle and lower elevation were sensitive in responding to temperature before 6000 cal. yr BP, but were not sensitive to the summer monsoon (SM). Since 6000 cal. yr BP, the CDF and TDF were sensitive in responding to the SM instead of temperature. Hence, a shift of response regimes can be placed at ∼6000 cal. yr BP, which happened to be consistent with the time that forest expansion changed to deforestation. The insensitive response to the SM during the early Holocene might be attributed to the vegetation elevational movement, the topographic barrier for forest migration from refugia, and/or the topographically related high resistance and resilience of mountain forests. The sensitive response of CDF and TDF to the weakening SM since 6000 cal. yr BP was mainly caused by the cumulative moisture deficit caused by the continual weakening of the SM. Human activity had little impact on mountain forests until several centuries ago. Mountain forest expansion in response to climate warming during the early to middle Holocene can provide analogues for the prediction of forest dynamics of future warming.