An invasive fish species within its native range: community effects and population dynamics of Gambusia affinis in the central United States
An invasive fish species within its native range: community effects and population dynamics of Gambusia affinis in the central United States
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原生范围内的入侵鱼类：美国中部甘布西亚 (Gambusia affinis) 的群落效应和种群动态
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
E. Marsh
中科院分区：
文献类型：
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作者：
W. J. Matthews;E. Marsh
摘要
1.入侵物种的 管理得益于关于入侵者生物学的详细信息，这些信息既来自入侵者已经入侵的地方，也来自于其原产地。西方蚊虫是一种入侵广泛、破坏性极强的淡水鱼。然而，在它的原生范围内，Gaffinis与许多其他鱼类在各种各样的栖息地共存，没有明显的伤害。
2. 在这项研究中，我们使用了广泛空间尺度上154个地点的赤眼蜂原生范围内鱼类群落的数据，以考察赤眼蜂对剩余(除赤眼蜂以外的物种)鱼类群落的物种丰富度和多样性的影响。我们进一步使用了基于8个固定河流站点18个夏季的年度样本的数据，以检验赤眼蜂的时间种群动态，并测试与种群波动相关的因素。
3.在棉铃虫存在的情况下， 具有较高的残留物种丰富度，但残留多样性没有差异。研究发现，赤眼蜂的相对丰富度与剩余物种丰富度呈负相关(虽然影响幅度极小)，但对剩余物种多样性没有影响。
4.在所有8个固定地点， affinis种群在夏季都有明显的波动，但一个地点的种群大小并不随时间的变化而自相关。然而，种群波动在所有年份的不同地点之间高度相关，这表明区域因素影响种群数量。棉铃虫的区域丰度与干旱、降雨或冬季温度无关，但随春季温度的变化而变化。我们认为，在温暖的春天繁殖的开始时间较早，导致夏季种群较多。
5. 总体而言，在其原生范围内，可能由于其密度的波动，海参似乎不会对其所在的组合产生负面影响。这些发现表明，引入的甘布斯虫种群以及其他入侵物种的种群需要对它们入侵的地方进行长时间的仔细监测。对新种群的长期监测可以确定它们是否容易出现“繁荣和萧条”的动态，在这种情况下，入侵者的威胁可能比有时认为的要小。因此，来自长期研究的种群信息，无论是在其原生范围内还是在入侵地点，都有助于形成对入侵生物采取谨慎、具有成本效益的管理战略的基础。
Summary
1. Management of invasive species benefits from detailed information on the biology of the invaders, both from where they have already invaded, and from within their areas of origin. Western mosquitofish, Gambusia affinis, is a widely invasive and destructive freshwater fish. However, within its native range, G. affinis co-exists with many other fish species in a wide variety of habitats without obvious harm.
2. In this study, we used data on fish communities within the native range of G. affinis at 154 sites across a broad spatial scale to examine the effects of G. affinis on species richness and diversity of residual (species other than G. affinis) fish assemblages. We further used data based on annual samples at eight fixed river sites over 18 summers to examine temporal population dynamics of G. affinis and to test factors associated with population fluctuations.
3. Higher residual species richness occurred in the presence of G. affinis, but residual diversity did not differ. We found an inverse relationship between relative abundance of G. affinis and residual species richness (although effect size was extremely small), but no effect on residual diversity.
4. Gambusia affinis populations fluctuated markedly across summers at all eight fixed sites, but population sizes at a site over time were not autocorrelated. However, population fluctuations were highly correlated among sites across all years, suggesting that regional factors influenced population size. Regional abundance of G. affinis did not correlate with drought, rainfall or winter temperature, but varied with spring temperature. We suggest earlier onset of reproduction in warmer springs resulted in larger summer populations.
5. Overall, within its native range, G. affinis does not appear to impact negatively on the assemblages in which it occurs, possibly due to fluctuations in its density. These findings suggest that introduced Gambusia populations, and those of other invasive species, warrant careful monitoring over long periods of time where they have invaded. Long-term monitoring of new populations can establish if they are prone to ‘boom and bust’ dynamics, in which case the invader may be less a threat than sometimes assumed. Population information from long-term studies, either in their native ranges or at invaded sites, can thus help to form the basis of prudent, cost-effective management strategies for invasive organisms.