Impact of species-specific dispersal and regional stochasticity on estimates of population viability in stream metapopulations
Impact of species-specific dispersal and regional stochasticity on estimates of population viability in stream metapopulations
复制标题
物种特异性扩散和区域随机性对河流集合种群中种群生存能力估计的影响
DOI：
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发表时间：
2012
影响因子：
5.2
通讯作者：
Donald A. Jackson
中科院分区：
文献类型：
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作者：
Mark S. Poos;Donald A. Jackson
物种扩散是元种群模型的核心组成部分。空间逼真的元种群模型，如随机斑块占用模型（SPOMs），利用基于斑块间距离（距离衰减模型）的定殖潜力估计来量化物种扩散。在本研究中，我们比较了SPOMs的参数化与直接由经验数据量化的分散和斑块动态。为此，我们监测了一种濒临灭绝的鲦鱼，红边鲷（Clinostomus elongatus）的两个大种群，使用标记-重新捕获技术，跨越43个斑块，在1年的时间内重新采样。超过2000条鱼被标记上可见的植入弹性体标签，用于标记斑块的位置和分散，并监测斑块的动态。我们发现，物种特异性扩散和距离衰减模型提供了质量相似的可生存斑块排名；然而，根据种群的不同，估计到灭绝的内在平均时间存在几个数量级的差异，从24年和148年到362年和10万年不等。我们还发现，区域随机率对物种生存能力的估计有很大的影响，并且在一个案例中改变了我们的元种群从有活力到无活力的轨迹。对灭绝时间的不同估计可能是由于物种特异性行为、溪流超种群的树突状性质和区域随机性的综合作用。我们证明了在确定平均灭绝时间的定量估计时，使用物种和斑块特定数据进行比较分析的重要性，在红边鲷的情况下，对不同的扩散估计高度敏感。
Species dispersal is a central component of metapopulation models. Spatially realistic metapopulation models, such as stochastic patch-occupancy models (SPOMs), quantify species dispersal using estimates of colonization potential based on inter-patch distance (distance decay model). In this study we compare the parameterization of SPOMs with dispersal and patch dynamics quantified directly from empirical data. For this purpose we monitored two metapopulations of an endangered minnow, redside dace (Clinostomus elongatus), using mark-recapture techniques across 43 patches, re-sampled across a 1 year period. More than 2,000 fish were marked with visible implant elastomer tags coded for patch location and dispersal and patch dynamics were monitored. We found that species-specific dispersal and distance decay models provided qualitatively similar rankings of viable patches; however, there were differences of several orders of magnitude in the estimated intrinsic mean times to extinction, from 24 and 148 years to 362 and >100,000 years, depending on the population. We also found that the rate of regional stochasicity had a dramatic impact for the estimate of species viability, and in one case altered the trajectory of our metapopulation from viable to non-viable. The divergent estimates in time to extinction times were likely due to a combination species-specific behavior, the dendritic nature of stream metapopulations, and the rate of regional stochasticity. We demonstrate the importance of developing comparative analyses using species- and patch-specific data when determining quantitative estimates for mean time to extinction, which in the case of redside dace, were highly sensitive to different estimates of dispersal.