Invasion of exotic piscivores causes losses of functional diversity and functionally unique species in Japanese lakes
Invasion of exotic piscivores causes losses of functional diversity and functionally unique species in Japanese lakes
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DOI：
10.1111/fwb.12774
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发表时间：
2016-07
影响因子：
2.7
通讯作者：
S. Matsuzaki;Takehiro Sasaki;M. Akasaka
中科院分区：
文献类型：
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作者：
S. Matsuzaki;Takehiro Sasaki;M. Akasaka
人类活动不仅影响物种丰富度（SR），也影响功能多样性（FD），但物种损失对功能多样性的影响在不同的群落中存在差异。功能独特物种的丧失可能导致FD的更大损失，破坏生态系统的长期持久性。我们量化了湖泊和流域尺度（N = 45）本地鱼类群落SR和FD的时间变化，并探讨了SR和FD下降与人为驱动因素和湖泊形态特征之间的关系。我们还模拟了随机物种损失，并将观测到的FD与预期FD进行了比较，以检查湖泊和流域中是否发生了功能独特的物种损失。总体而言，湖泊尺度的SR和FD从历史到现在（2000年以来）分别下降了72.1%和75.5%，但由于一些从湖泊消失的物种在周围水体中持续存在，流域尺度的损失率有所减轻。在我们考虑的驱动因素中，外来鱼类的丰富度是SR和FD变化的最重要预测因子。外来鱼鱼丰富度的增加降低了SR和FD。不同湖泊间物种流失对FD的影响不尽相同。在湖泊尺度上，有18个湖泊出现了功能独特物种的丧失，这些物种往往与外来鱼类丰富度的增加有关。然而，在18个湖泊中的5个湖泊中，功能独特的物种在周围水体中持续存在。这些物种的持续存在可能会增加湖泊鱼类群落的FD。我们的研究结果表明，对外来鱼类和湖泊及其周围水体之间的相互联系进行战略管理对于确保本地鱼类组合的持久性和相关的生态功能至关重要。
Summary Human activities affect not only species richness (SR) but also functional diversity (FD), but the consequences of species loss on FD may vary among communities. The loss of functionally unique species can result in a greater loss of FD, undermining the long-term persistence of ecosystems. We quantified the temporal changes in the SR and FD of native fish communities at the lake and drainage basin scales (N = 45), and investigated the relationships among these declines in SR and FD, anthropogenic drivers, and lake morphometric characteristics. We also simulated random species loss and compared the observed FD to the expected FD to examine whether losses of functionally unique species from the lakes and drainage basins had occurred. Overall, SR and FD at the lake scale decreased by 72.1 and 75.5% from historical to current (since 2000) time periods, respectively, but the loss rates were mitigated at the drainage basin scale because some of the species that have disappeared from lakes persist in the surrounding waterbodies. Of the drivers we considered, the richness of exotic piscivores was the most important predictor of changes in both SR and FD. Increases in exotic piscivore richness reduced the SR and FD. The consequences of species loss on FD varied among the lakes. Loss of functionally unique species at the lake scale occurred in 18 lakes and tended to be associated with increased exotic piscivore richness. In 5 of the 18 lakes, however, functionally unique species persist in the surrounding waterbodies. The persistence of these species may have the potential to increase the FD of lake fish communities. Our findings suggest the importance of the strategic management of exotic piscivores and interconnections between lakes and their surrounding waterbodies to ensure the persistence of native fish assemblages and associated ecological functionality.