Combining projected changes in species richness and composition reveals climate change impacts on coastal Mediterranean fish assemblages
Combining projected changes in species richness and composition reveals climate change impacts on coastal Mediterranean fish assemblages
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DOI：
10.1111/j.1365-2486.2012.02772.x
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发表时间：
2012-10-01
影响因子：
11.6
通讯作者：
Leprieur, Fabien
中科院分区：
文献类型：
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作者：
Albouy, Camille;Guilhaumon, Francois;Leprieur, Fabien
物种时间更替（STT）是评估气候变化导致的组合组成变化的最熟悉的指标之一。然而，STT 在一个度量中混合了两个组成部分，即由物种损失或增加过程引起的组合组成的变化（即嵌套成分）和由物种替换过程引起的组合组成的变化（即物种替换部分）。借鉴之前对 beta 多样性空间模式的研究，我们提出了 STT 的测量方法，可以分别分析每个组成部分（物种替换与嵌套）。我们还提出了一种绘图策略，可以同时可视化物种丰富度和组合组成的变化。为了说明我们的方法，我们使用地中海沿岸鱼类区系作为案例研究。使用生物气候包络模型 (BEM)，我们首先根据全球变暖情景预测了 288 种地中海沿海鱼类的未来潜在气候生态位。然后，我们在地理上汇总了物种层面的预测，以分析物种丰富度和组成的预测变化。我们的结果表明，组合组成的预计变化是由地中海几个区域的不同过程（物种替换与嵌套）引起的。此外，我们的绘图策略强调，如果暴露于气候变暖，地中海几个地区的沿海鱼类区系可能会经历死胡同效应。总体而言，联合探索物种丰富度和组成的变化以及物种替代和嵌套之间的区别，为了解气候变化对生物多样性影响的性质提供了重要信息。这些方法上的进步应有助于决策者优先考虑在最容易受到气候影响的地区采取的行动。
Species Temporal Turnover (STT) is one of the most familiar metrics to assess changes in assemblage composition as a consequence of climate change. However, STT mixes two components in one metric, changes in assemblage composition caused by a process of species loss or gain (i.e. the nestedness component) and changes in assemblage composition caused by a process of species replacement (i.e. the species replacement component). Drawing on previous studies investigating spatial patterns of beta diversity, we propose measures of STT that allow analysing each component (species replacement vs. nestedness), separately. We also present a mapping strategy to simultaneously visualize changes in species richness and assemblage composition. To illustrate our approach, we used the Mediterranean coastal fish fauna as a case study. Using Bioclimatic Envelope Models (BEMs) we first projected the potential future climatic niches of 288 coastal Mediterranean fish species based on a global warming scenario. We then aggregated geographically the species-level projections to analyse the projected changes in species richness and composition. Our results show that projected changes in assemblage composition are caused by different processes (species replacement vs. nestedness) in several areas of the Mediterranean Sea. In addition, our mapping strategy highlights that the coastal fish fauna in several regions of the Mediterranean Sea could experience a cul-de-sac effect if exposed to climate warming. Overall, the joint exploration of changes in species richness and composition coupled with the distinction between species replacement and nestedness bears important information for understanding the nature of climate change impacts on biodiversity. These methodological advances should help decision-makers in prioritizing action in the areas facing the greatest vulnerability to climate.