【作者】 刘锋；

【导师】 胡金明；

【作者基本信息】 云南大学 ， 自然地理学， 2023， 博士

【摘要】 认识物种多样性分布格局及其动态变化是实现长期有效保护生物多样性的关键。物种分布区、物种丰富度变化,尤其是生物群落物种组成及其结构的快速重组(生物同质化或异质化)会对气候变化下的生物多样性保护带来极大的挑战。然而,目前较少有研究探讨在保护实践中如何应对气候变化下生物多样性重组。青藏高原是全球重要的维管植物多样性热点地区,也是未来全球气候变化最突出的地区之一,当前和未来气候变化情景下的青藏高原维管植物多样性的保护一直是学术界关注的热点问题。然而,已有的研究还不足以全面深入地认知当前和未来气候变化情景下的青藏高原维管植物多样性分布格局,对气候变化情景下青藏高原维管植物多样性的重组也所知较少,难以为青藏高原维管植物多样性的长期有效保护提供坚实的理论支撑。本研究系统地收集、整理和构建了青藏高原维管植物分布数据库。在此基础上,我们采用当前和未来三个时期(2050s、2070s、2090s),两种共享社会经济路径(SSP1-2.6、SSP5-8.5)的气候数据,设置三类物种扩散情景(完全扩散、适宜扩散、无扩散),利用物种分布模型和系统保护规划等方法:(1)模拟青藏高原当前7187种维管植物多样性的分布格局,评估当前气候情景下已建保护地对青藏高原维管植物物种的保护成效;(2)预测青藏高原7187种维管植物物种分布区,揭示未来气候变化情景下青藏高原维管植物多样性(物种和群落水平)的重组趋势;(3)比较分析已建保护地和本研究识别的未来气候变化情景下的青藏高原维管植物优先保护区域、气候变化避难所的保护成效,揭示不同区域保护策略在应对气候变化下青藏高原维管植物多样性重组的保护价值。主要研究结论如下:1)当前气候情景下,青藏高原维管植物α多样性分布格局整体上由东南至西北递减,热点地区主要位于横断山区和东喜马拉雅山地。2)当前气候情景下,已建保护地对青藏高原维管植物物种的保护效率仅为19.1%,而且已建保护地仅能覆盖本研究识别的优先保护区域约1/4左右的面积,可见青藏高原存在明显的维管植物保护空缺,迫切需要加强保护地体系的优化,以实现青藏高原维管植物的有效保护。3)未来气候变化情景下,青藏高原维管植物物种分布区将会发生明显变化,物种分布区的收缩或扩张趋势更多地取决于物种扩散能力。维管植物整体上向上、向北、向西迁移,物种之间在扩散方向和速率上表现出显著的异步性。4)未来气候变化情景下,青藏高原维管植物群落的α多样性、物种组成及结构呈现快速重组。与物种水平相似,群落水平的重组幅度(趋势)也同样受到物种扩散能力的制约。对于α多样性变化来说,不扩散情景下,横断山区与东喜玛拉雅山地区域是维管植物物种丧失中心,这主要是由狭域植物局域灭绝驱动的;在扩散情景下(完全扩散和适宜扩散),三江源、横断山区北部、雅鲁藏布江大峡谷地区以及喜马拉雅山南坡沟谷区域则是物种增加中心。对于空间β多样性变化来说,气候变化情景下物种的迁入或迁出将会改变局域维管植物群落之间物种组成的相似性,进而导致区域呈现生物同质化或异质化;在不扩散情景下维管植物群落更多的是呈现生物异质化,而在扩散情景下则更多的是呈现生物同质化。对于时间β多样性(物种组成变化)来说,不扩散情景下未来维管植物群落物种组成变化完全由物种丧失决定,而在扩散情景下驱动时间β多样性的嵌套组分和物种周转组分因地理空间而异。另外,气候变化情景下青藏高原维管植物多样性重组在不同生物区系之间呈现显著的地理分异。5)通过比较已建保护地、本研究识别的优先保护区域和气候变化避难所三类不同区域保护策略的保护成效。研究发现已建保护地对气候变化情景下青藏高原维管植物物种和维管植物多样性重组的保护成效是最低的,优先保护区域在应对气候变化情景下维管植物物种的保护时效果最佳,而气候变化避难所则更能有效应对未来气候变化情景下的青藏高原维管植物多样性重组。本研究认为,迫切需要面向青藏高原维管植物保护来开展已建保护地的优化。权衡未来气候变化下物种和维管植物多样性重组的保护需求,综合考虑不同的区域保护策略,才有可能实现当前和未来气候情景下青藏高原维管植物多样性的长期有效保护。更多还原

【Abstract】 Comprehending the distribution patterns and dynamic changes of species diversity is imperative for achieving long-term effective conservation of biodiversity.Changes in species distribution,species richness and particularly the rapid reorganization(biotic homogenization or heterogenization)of biological community’s species composition and structure will present significant challenges to biodiversity conservation under climate change.However,limited research has been conducted to investigate the incorporation of biodiversity restructuring into conservation practices in response to climate change.The Qinghai-Tibetan Plateau(QTP)is an important hotspot for vascular plant diversity in the world,and it is also one of the most prominent regions of global climate change in the future.The conservation of vascular plant diversity in the QTP under current and future climate change scenarios has been a hot issue of concern to researchers.Nevertheless,the current studies are insufficient to comprehensively and deeply understand the distribution pattern of vascular plant diversity under present and future climate change scenarios.Furthermore,there is limited knowledge regarding the reorganization of vascular plant diversity under climate change,which hinders providing robust theoretical support for the long-term effective conservation of vascular plant diversity in the QTP.In this study,the distribution database of vascular plants in the QTP was systematically collected,sorted out and constructed.On this basis,we utilize climate data from the current and future three time periods(2050s,2070s,2090s),two shared socio-economic pathways(SSP1-2.6,SSP5-8.5),and establish three species dispersal scenarios(full dispersal,limited dispersal,and no dispersal)by employing species distribution models and systematic conservation planning to(1)Simulate the current distribution pattern of 7187 vascular plant diversity in the QTP,and evaluate the conservation effectiveness of established protected areas for vascular plant species in the QTP under current climate scenarios;(2)After predicting the potential range of 7187 vascular plant species,this study revealed how vascular plant diversity reorganized at the species and community level under climate change in the QinghaiTibetan Platea;(3)The conservation effectiveness of established protected areas,as well as the priority conservation areas and climate change refugia for vascular plants identified in this study,were assessed and compared.This analysis sheds light on the significance of the conservation value of different area-based conservation strategies in managing the reorganization of vascular plant diversity in the QTP under future climate change.The main conclusions are as follows:1)Under the current climate scenario,α diversity distribution pattern of vascular plants in the QTP decreases from southeast to northwest on the whole,and the hotspots are mainly located in the Hengduan Mountains and the Eastern Himalaya Mountains.2)Under the current climate scenario,the protection efficiency of established protected areas for vascular plant species in the QTP is only 19.1%,and the established protected areas can only cover about 1/4 of the priority conservation areas identified in this study,indicating that there is an obvious vascular plant conservation gaps in the QTP,and it is urgent to strengthen the optimization of the protected area system.To achieve effective protection of vascular plants in the QTP.3)Under the future climate change scenario,the species distribution of vascular plants in the QTP will change significantly,and the contraction or expansion trend of species distribution depends more on the dispersal ability of species.The migration of vascular plants exhibited a collective upward,northward,and westward movement,while demonstrating significant asynchrony in both the direction and rate of dispersion among various species.4)Under future climate change scenarios,α diversity,species composition and structure of the vascular plant community in QTP showed rapid reorganization.Similar to the species level,the magnitude(tendency)of reorganization at the community level is also limited by the dispersal capacity of species.Regarding the variation in a diversity,the Hengduan Mountains and Eastern Himalayan Mountains are identified as key regions for vascular plant species loss under the no-dispersal scenario,primarily due to the local extinction of narrow-ranged plants.Under the dispersal scenario(Full and limited dispersal),the species expansion centers were situated in the Three-RiverSource Region,the northern Hengduan Mountains,the Yarlung Zangbo Grand Canyon,and the Himalayas’ southern slope ravine.Spatial β diversity changes arise from species migration or emigration in response to climate change,altering the similarity of species composition among local vascular plant communities in the QTP,leading to biotic homogenization in certain regions and heterogenization in others.The no-dispersal scenario exhibited a higher degree of biotic homogenization in vascular plant communities,whereas the dispersal scenario demonstrated a greater level of biotic heterogenization.Temporal β-diversity(changes in species composition over time)was exclusively driven by species loss in the no-dispersal scenario,leading to future alterations in vascular plant community species composition,whereas the contributions of nested components and species turnover components to temporal β-diversity in the dispersal scenario vary spatially.In addition,under the climate change scenario,the reorganization of vascular plant diversity in the QTP also showed significant geographical differentiating among different biomes.5)By comparing the conservation effectiveness of different area-based conservation strategies,namely established protected areas,priority conservation areas and climate change refugia identified in this study.It was determined that established protected areas exhibited the least efficacy in safeguarding vascular plant species and reorganization of vascular plant diversity under climate change.Conversely,the priority conservation areas have the best effect on the protection of vascular plant species under climate change,while the climate change refugia is more effective in dealing with the restructuring of vascular plant diversity in the QTP.This study concluded that it is urgent to optimize the established protected areas for vascular plant conservation in the QTP.Trading off the conservation requirements of species and reorganizing vascular plant diversity under future climate change while considering various area-based conservation strategies,it is possible to achieve longterm and effective conservation of vascular plant diversity in the QTP under current and future climate scenarios.更多还原