Beaver-created successional gradients increase β-diversity of invertebrates by turnover in stream-wetland complexes
Beaver-created successional gradients increase β-diversity of invertebrates by turnover in stream-wetland complexes
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DOI：
10.1111/fwb.13302
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发表时间：
2019-07-01
影响因子：
2.7
通讯作者：
Batzer, Darold P.
中科院分区：
文献类型：
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作者：
Bush, Bryana M.;Stenert, Cristina;Batzer, Darold P.
海狸是众所周知的生态系统工程师，主要通过修建水坝来改变环境。海狸湿地是河流网络中新创建的、成熟的和废弃的海狸建筑的综合体。从这些演替阶段衍生的所有生境中的无脊椎动物动态仍然没有得到很好的研究。在这里，我们测试这种由海狸创造的自然演替梯度如何影响无脊椎动物的β-多样性及其组成部分(周转和筑巢)。无脊椎动物是在美国佐治亚州的皮埃蒙特地区采集的。在栖息地演替的四个阶段中，每两个季节(秋季和春季)：自然河道、由新形成的河狸大坝创造的森林湿地、成熟的开阔湿地沼泽和废弃的湿地草甸。秋季，除了新湿地与废弃湿地、新湿地与成熟湿地以及溪流与废弃湿地外，无脊椎动物群落在不同演替阶段均有所不同。春季，只有成熟的河狸湿地群落是独特的，既不同于溪流，也不同于新形成的或废弃的湿地。整个研究系统的β多样性几乎是任何个体演替阶段的两倍，这两个阶段都有类似的多样性。此外，在所有阶段，营业额都显著高于筑巢。群落的差异和演替阶段的高周转率表明，海狸湿地群落不仅仅是更稳定的成熟湿地或溪流的子集；相反，每个阶段都有不同的分类组成。我们的结果强化了这样一种观点，即海狸活动可以成为一种重要的保护工具，因为它大大促进了它们所在地区的多样性。面对气候变化和其他人类影响造成的湿地丧失，海狸湿地具有帮助稳定贝塔和区域多样性的潜力。
Beavers are ecosystem engineers known to modify the environment primarily via dam building. Beaver wetlands are complexes of newly created, mature, and abandoned beaver constructions within a stream network. Invertebrate dynamics across all habitats derived from these successional stages remains poorly explored. Here, we test how this natural successional gradient created by beaver affects invertebrate beta-diversity and its components (turnover and nestedness). Invertebrates were sampled in the Piedmont region of Georgia (U.S.A.) in two seasons (autumn and spring) in each of four stages of habitat succession: natural stream channels, forested wetlands created by newly formed beaver dams, mature open wetland marshes, and abandoned wetland meadows. In autumn, invertebrate communities were different among successional stages, apart from new versus abandoned wetlands and new versus mature wetlands, which were only marginally different, and streams versus abandoned wetlands. In spring, only the mature beaver wetland communities were unique, differing from both streams and from newly formed or abandoned wetlands. Beta-diversity was nearly twice as high for the overall study-system than any individual successional stage, which all had similar diversity. Additionally, turnover was significantly higher than nestedness in all stages. Community differences combined with high turnover among successional stages indicates that beaver wetland communities are not merely a subset of more stable mature wetlands or streams; instead, each stage has a different taxonomic make-up. Our results strengthen the idea that beaver activity can be an important conservation tool by contributing substantially to diversity in areas where they are present. Beaver wetlands have the potential to help stabilise beta- and regional diversity in the face of wetland loss from climate change and other human impacts.