Local and regional drivers influence how aquatic community diversity, resistance and resilience vary in response to drying
Local and regional drivers influence how aquatic community diversity, resistance and resilience vary in response to drying
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DOI：
10.1111/oik.07645
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发表时间：
2020-09
期刊：
影响因子：
3.4
通讯作者：
Romain Sarremejane;J. England;C. Sefton;S. Parry;Michael Eastman;R. Stubbington
中科院分区：
文献类型：
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作者：
Romain Sarremejane;J. England;C. Sefton;S. Parry;Michael Eastman;R. Stubbington
干扰事件控制着生态群落的生物多样性在空间和时间上的变化。在淡水生态系统中，有证据表明，地方和区域尺度的驱动因素相互作用，影响对干旱干扰的生态反应。然而，大多数研究提供了当地尺度的时间快照，而很少有研究涵盖多年干燥严重程度的梯度。使用一个罕见的时空范围和细节的数据集，我们展示了独立和相互作用的局部和区域尺度因素如何驱动动态河流生态系统中群落的α和β多样性的变化。我们研究了30个地点的水生无脊椎动物群落对水文变异性的响应(以每月观测河流状况为特征)，时间跨度为12年，包括典型年份和两次严重干旱扰动。在当地(即特定地点)和区域(即河流集水区)尺度上，不同地点的干扰制度和水文连通性各不相同。虽然α多样性主要受局部因素的影响，包括水流的持久性和积水和干旱的时间范围，但β的时间和空间多样性也响应区域尺度的度量，如水流的空间范围和水文连通性。我们观察到具有较低耐旱能力(即抗性)和/或在水流恢复后恢复能力(即恢复能力)的分类群具有更强的局部负面反应，而具有促进恢复能力的功能特征的分类群对空间β多样性的贡献随着水文连通性的下降而增加。随着全球地区干旱程度和严重程度的增加，我们的发现突出了分类对干扰和连通性做出反应的功能基础，从而促进了对干旱干扰如何塑造河网生物多样性的理解。我们对区域水文因素作用的确定可以为流域规模的管理战略提供信息，以支持在全球变化背景下的生态系统复原力。
Disturbance events govern how the biodiversity of ecological communities varies in both space and time. In freshwater ecosystems, there is evidence that local and regional‐scale drivers interact to influence ecological responses to drying disturbances. However, most research provides temporal snapshots at the local scale, whereas few studies encompass a gradient of drying severity spanning multiple years. Using a dataset of rare spatiotemporal extent and detail, we demonstrate how independent and interacting local and regional‐scale factors drive shifts in the α and β diversities of communities in dynamic river ecosystems. We examined aquatic invertebrate assemblage responses to hydrological variability (as characterized by monthly observations of instream conditions) at 30 sites over a 12‐year period encompassing typical years and two severe drought disturbances. Sites varied in their disturbance regimes and hydrological connectivity at both local (i.e. site‐specific) and regional (i.e. river catchment) scales. Whereas α diversity was mainly influenced by local factors including flow permanence and the temporal extent of ponded and dry conditions, both temporal and spatial β diversities also responded to regional‐scale metrics such as the spatial extent of flow and hydrological connectivity. We observed stronger local negative responses for taxa with lower capacities to tolerate drying (i.e. resistance) and/or to recover after flow resumes (i.e. resilience), whereas taxa with functional traits promoting resilience made an increasing contribution to spatial β diversity as hydrological connectivity declined. As droughts increase in extent and severity across global regions, our findings highlight the functional basis of taxonomic responses to disturbance and connectivity, and thus advance understanding of how drying disturbances shape biodiversity in river networks. Our identification of the role of regional hydrological factors could inform catchment‐scale management strategies that support ecosystem resilience in a context of global change.