Data from: Spatial heterogeneity of tree diversity changes in montane forests under climate warming

Many studies reported biotic change along a continental warming gradient. The temporal and spatial change of tree diversity and their sensitivity to climate warming might differ from region to region. however, understanding of the variation among studies with regard to the magnitude of such biotic changes is minimal, especially for montane ecosystems. To better understand spatial heterogeneity and temporal dynamics of mountain trees community change under climate warming over the past four decades. We re-surveyed and recorded all tree species from 107 long-term monitoring plots since 1974 in 2017 to study the changes of tree community composition of montane forests in the Giant Panda National Park. Our results showed that spatial differences were found in tree species diversity changes in response to climate warming over the past four decades. Tree species richness and abundance of montane forests increased over time in all our study area, except Liangshan (LS), especially in XiaoXiangLing with the highest warming rate. However, beta diversity underwent a significantly higher change rate at LS than in other mountains which indicated that plant species that do not belong to these four mountains entered LS in those year. Moreover, the beta diversities of tree between sample plots in the LS regions were homogenized. So, LS may become risk regions under continuing climatic warming, and should thus receive priority protection in the next conservation plan of the Giant Panda National Park (GPNP). We provide a explanation for the large variation among studies in warming-related biotic changes and recommend that the GPNP should implement a regional-specific conservation policy to strengthen conservation in at-risk regions (i.e., LS) under climate warming.

诸多研究均报道了沿大陆变暖梯度发生的生物群落变化。树木多样性的时空变化及其对气候变暖的敏感性可能因区域而异。然而，现有研究对这类生物变化幅度的区域差异认知仍十分有限，针对山地生态系统（montane ecosystems）的相关研究更是如此。为更深入理解过去四十年来气候变暖背景下山地树木群落变化的空间异质性与时间动态，本研究于2017年对大熊猫国家公园内自1974年起设立的107个长期监测样地中的所有树木物种进行了重新调查与记录，以此探究该区域山地森林的树木群落组成变化。研究结果显示，过去四十年来，树木物种多样性对气候变暖的响应存在空间差异：除凉山（Liangshan, LS）外，研究区域内所有山地森林的树木物种丰富度与多度均随时间推移有所提升，其中升温速率最高的小相岭（Xiaoxiangling）提升最为显著。然而，凉山的β多样性（beta diversity）变化速率显著高于其他山地，表明非本研究涉及的四大山地的植物物种在近年迁入了凉山。此外，凉山区域内各样地间的树木β多样性已趋于均质化。因此，在持续气候变暖背景下，凉山或将成为气候风险区域，应在大熊猫国家公园（Giant Panda National Park, GPNP）后续的保护规划中获得优先保护。本研究为解释不同研究中气候变暖相关生物变化的显著差异提供了依据，并建议大熊猫国家公园应制定区域差异化保护策略，以加强气候变暖背景下风险区域（即凉山）的保护工作。