文献阅读 260513-Climate-induced range shifts support local plant diversity but don’t reduce extinction r

Climate-induced range shifts support local plant diversity but don’t reduce extinction risk来自 https://www.science.org/doi/10.1126/science.aea1676## Abstract:# Rise the question: climate change and biodiversityClimate change is driving widespread plant range shifts,yettheir consequences for extinction and biodiversityremain unclear as realistic range shift dynamics have rarely been incorporated into global-scale biodiversity models.# How this paper solved this question:Weintegrate species-specific range shift velocities into species distribution modelsto project distributions of 67,664 plant species (18% of all global flora) by 2081 to 2100. Across emissions scenarios, 7 to 16% of species are projected to lose 90% of their range, placing them at high risk of extinction.#Results↑and mechanisms↓:These losses are driven primarily byclimate-induced habitat loss, rather than dispersal limitation. Although range shifts offer little relief from global extinctions, they are projected to increase local plant richness across 28% of Earth’s land. Facilitating range shifts may thus sustain local richness but not reduce global extinctions.## Intro:Some interesting parts:# Para1: Background of this question,Anthropogenic climate change has induced plant range shifts worldwide (1), with far-reaching consequences for biodiversity, ecosystem functioning, and human well-being (2). Although some plant species can persist within their current ranges through phenotypic plasticity or rapid evolution (3),many may need to track climate-driven shifts in suitable habitats(4, 5).Their ability to do so largely depends on theirdispersal capacity, which varies widely across species(6, 7). However, dispersal capacity remains notoriously difficult to quantify, given limited observations and its potential to evolve rapidly under climate change (8–10). Consequently, forecasts of global extinctions and biodiversity change under climate change often rely on overly simplistic dispersal assumptions (e.g., no dispersal, unlimited dispersal, or uniform dispersal rates across species) (11, 12), introducing substantial uncertainty into projections (13).Climate-induced habitat loss, not dispersal limitation, drives projected global extinctionsPlant range shifts maintain local species richnessUncertainties in projecting plant species richness changes总体而言在各种排放情景下预计有7%至16%的模拟植物物种将丧失其90%以上的分布范围从而面临极高的灭绝风险。这些损失中的绝大部分70%至80%归因于气候变化导致的适宜栖息地消失而非物种扩散能力受限这表明气候引发的栖息地丧失才是主要威胁而非物种无法跟上气候变化的步伐。尽管分布范围的迁移不太可能阻止许多物种在全球范围内灭绝但它将极大地重塑局地的物种组成。预计植物向新形成的适宜栖息地迁移将使地球陆地表面28%的区域实现局地物种丰富度增加在热带和亚热带地区南纬35°至北纬35°这种迁移将维持其在纬度尺度上的平均物种丰富度而在中纬度地区南北半球30°至50°之间则将引发显著的物种更替。相比之下在北纬50°以北的地区气候变暖的速度过于迅猛致使大多数植物无法及时适应进而导致大范围的局地物种灭绝局地绝迹以及物种丰富度的急剧下降。物种分布范围的迁移有助于维持局部的物种丰富度但不太可能对缓解全球性物种灭绝提供实质性的助益。为了降低灭绝风险识别并保护气候变化避难所以维护生物多样性以及拓展全球种子库和植物园网络等迁地保护工作可能比单纯促进物种迁移更为有效。与此同时随着新物种的迁入及生态系统的重组群落组成和生态系统功能势必发生变化因此保护策略应当预见并应对这些变化。在高纬度地区由于物种扩散的速度远滞后于气候变暖的迅猛步伐改善栖息地的连通性、减少人为设置的障碍并在适宜的情况下辅助物种迁移将有助于维持当地的物种丰富度、生态系统生产力、碳固存能力以及生态系统的稳定性。