Stream community and ecosystem responses to the boom and bust of an invading snail
Stream community and ecosystem responses to the boom and bust of an invading snail
复制标题
流媒体社区和生态系统对入侵蜗牛的繁荣和萧条的反应
DOI：
10.1007/s10530-012-0240-y
复制
发表时间：
2012
影响因子：
2.9
通讯作者：
S. Carlson
中科院分区：
文献类型：
--
作者：
J. Moore;D. Herbst;W. Heady;S. Carlson
入侵物种可以从根本上改变生态系统，但令人惊讶的是，人们对它们如何随着时间的推移改变生态系统的了解仍然很少。新西兰泥螺（NZMS，Potamopyrgus antipodarum）正在入侵北美水生生态系统，对溪流群落和生态系统产生潜在的巨大影响。在这里，我们提出了一个独特的10年的时间序列流底栖无脊椎动物在两个网站在加州流一个入侵的网站，NZMS人口蓬勃发展，然后破灭，和一个上游的参考网站，没有入侵到相同的程度。随着NZMS种群的上升和下降，大量的本地放牧食草动物崩溃，然后恢复，NZMS直接的负面竞争影响的证据。然而，NZMS有一个积极的间接影响刺穿草食动物，可能介导的优势藻类类型的转变。回顾性稳定同位素分析和贝叶斯同位素混合模型表明，NZMS入侵减少了依赖本地类群，从各种功能的喂养组，对附着生物衍生的碳。此外，NZMS入侵与贫氮稳定同位素的签名，证据表明，NZMS改变流生态系统氮循环。参考网站没有显示这些社区或生态系统层面的动态。因此，入侵的食草动物可以对入侵的生态系统产生强烈的自上而下和自下而上的影响，但这些影响可能是非常动态的。
Invasive species can fundamentally change ecosystems, but there remains surprisingly little understanding of how they alter ecosystems through time. New Zealand mudsnails (NZMS, Potamopyrgus antipodarum) are invading North American aquatic ecosystems with potentially enormous impacts on stream communities and ecosystems. Here we present a unique 10 year time series of stream benthic invertebrates in two sites in a California stream—one invaded site where NZMS populations boomed and then busted, and one upstream reference site that was not invaded to the same degree. As NZMS populations rose and fell, the abundance of native grazing herbivores crashed and then recovered, evidence of direct negative competitive impacts of NZMS. However, NZMS had a positive indirect effect on piercing herbivores, probably mediated by a shift in the dominant algal type. Retrospective stable isotope analyses and Bayesian isotopic mixing models revealed that NZMS invasion decreased the reliance of native taxa, from a variety of functional feeding groups, on periphyton-derived carbon. Furthermore, NZMS invasion was associated with depleted nitrogen stable isotope signatures, evidence that NZMS alter stream ecosystem nitrogen cycling. The reference site did not exhibit these community- or ecosystem-level dynamics. Thus, invasive herbivores can have strong top-down and bottom-up influences on invaded ecosystems, but these impacts can be extremely temporally dynamic.