Treeline composition and biodiversity change on the southeastern Tibetan Plateau during the past millennium, inferred from a high-resolution alpine pollen record
Treeline composition and biodiversity change on the southeastern Tibetan Plateau during the past millennium, inferred from a high-resolution alpine pollen record
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从高分辨率高山花粉记录推断青藏高原东南部近千年来的林线组成和生物多样性变化
DOI：
10.1016/j.quascirev.2018.12.029
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发表时间：
2019-02-15
影响因子：
4
通讯作者：
Wang, Yongbo
中科院分区：
文献类型：
--
作者：
Li, Kai;Liao, Mengna;Wang, Yongbo
气候变化一直在影响陆地生态系统。然而，一些重要的过程有关的植被对气候变化的反应在高山地区，如树线组成和相关的植物多样性的变化，还没有得到很好的理解，在数百年的尺度。本文利用青藏高原东南部巴松措地区的高分辨率孢粉学资料，探讨了该地区植被变化及其对气候的影响。结果表明，在过去的千年里，巴松措周围的树线位置，组成和植物多样性发生了很大的变化。冷事件（cold event）720-650 cal yr BP和ca. 400-50 cal yr BP）被认为是迫使这些变化的关键。寒冷的气温限制了高海拔树木的生长，导致树线下坡移动，优势树种明显减少。上层森林释放出的空间和资源促使灌木和草本植物向低海拔地区扩展，甚至有新的物种可以扩散到这一地区并存活下来，导致植被组成和多样性发生变化。虽然世纪以来气候变暖明显，但林线分布、植被组成和物种多样性似乎还没有从之前的寒冷时期恢复过来。在未来几十年内，青藏高原东南部山区植被演替可能会缓慢发展。我们的研究结果强调，需要长期的气候和植被监测和分析，以更好地了解在气候转型期的树线运动和植物多样性变化的区域动态。(C)2019爱思唯尔有限公司版权所有。
Climate variability has been impacting the terrestrial ecosystems. However, some important processes relating to the response of vegetation to climate change in alpine regions, such as treeline composition and associated plant diversity change, have not been well understood in terms of multi-centennial scales. Here, we present a well-dated high-resolution palynological record from Basomtso, southeastern Tibetan Plateau (TP), to discuss the vegetation change and the relevant climate forcing. Our results manifest that the treeline position, composition and plant diversity around Basomtso did change greatly during the past millennium. The cold events (ca. 720-650 cal yr BP and ca. 400-50 cal yr BP) were considered crucial to force these changes. Cold temperature limited the growth of trees in the high elevations and thus led to downslope movement of treeline and conspicuous decrease of dominant tree species. Space and resource released from the upper forest triggered shrub and herb taxa expanded to lower elevations and even new species can dispersed to this area and survived, leading to changes in vegetation composition and diversity. Although the climate warming is pronounced since the 20th century, treeline distribution, vegetation composition and species diversity seem have not been recovered from the previous cold period. And the vegetation succession in the mountains of the southeastern TP will probably develop slowly in the coming decades. Our results highlight the need for long-term climate and vegetation monitoring and analysis in order to better understand the regional dynamics of treeline movement and plant diversity change during climate transition period. (C) 2019 Elsevier Ltd. All rights reserved.