Climate and land-use changes interact to drive long-term reorganization of riverine fish communities globally
Climate and land-use changes interact to drive long-term reorganization of riverine fish communities globally
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DOI：
10.1073/pnas.2011639118
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发表时间：
2021-07-06
影响因子：
11.1
通讯作者：
Giam, Xingli
中科院分区：
文献类型：
--
作者：
Comte, Lise;Olden, Julian D.;Giam, Xingli
随着气候变化的展开，种群动态和物种分布范围的变化预计将从根本上重新洗牌世界各地的社区。然而，对社区重组的机制和程度的全面了解仍然难以捉摸。在河流系统中尤其如此，这些系统同时暴露在不断变化的温度和径流中，而土地利用的变化仍然是生物多样性丧失的主要驱动因素。在这里，我们使用迄今为止最全面的鱼类丰度时间序列汇编，以提供气候和LU诱导的关于物种热亲和力和径流亲和力变化对河流生物群影响的全球综合。我们证明，鱼类群落越来越多地被嗜热(温水)和嗜湖(慢水)物种所主导。尽管与近几十年观察到的水温和径流趋势一致，但这些群落变化似乎在很大程度上彼此脱钩，并显示出广泛的空间差异。我们进一步揭示了与气候和土地利用相关的驱动因素之间的协同作用，这样在更多的人类修改的系统中，社区的嗜热性得到了加强。重要的是，物种经历接近或超过其耐受阈值的热和流动制度的群落(高群落敏感度)以及物种贫乏的群落(低群落复原力)，也表现出更快的组成变化速度。这项研究表明，量化河流系统对气候变化的脆弱性需要从更狭隘的热焦点扩大到更综合的方法，这些方法考虑到河流生物对水温、水文和其他人为变化的交互影响的空间变化和多方面的敏感性。
As climate change unfolds, changes in population dynamics and species distribution ranges are expected to fundamentally reshuffle communities worldwide. Yet, a comprehensive understanding of the mechanisms and extent of community reorganization remains elusive. This is particularly true in riverine systems, which are simultaneously exposed to changing temperature and streamflow, and where land-use change continues to be a major driver of biodiversity loss. Here, we use the most comprehensive compilation of fish abundance time series to date to provide a global synthesis of climate- and LU-induced effects on riverine biota with respect to changes in species thermal and streamflow affinities. We demonstrate that fish communities are increasingly dominated by thermophilic (warm-water) and limnophilic (slow-water) species. Despite being consistent with trends in water temperature and streamflow observed over recent decades, these community changes appear largely decoupled from each other and show wide spatial variation. We further reveal a synergy among climate- and land use-related drivers, such that community thermophilization is heightened in more human-modified systems. Importantly, communities in which species experience thermal and flow regimes that approach or exceed their tolerance thresholds (high community sensitivity), as well as species-poor communities (low community resilience), also display faster rates of compositional change. This research illustrates that quantifying vulnerability of riverine systems to climate change requires a broadening from a narrower thermal focus to more integrative approaches that account for the spatially varying and multifaceted sensitivity of riverine organisms to the interactive effects of water temperature, hydrology, and other anthropogenic changes.