Population variability complicates the accurate detection of climate change responses
Population variability complicates the accurate detection of climate change responses
复制标题
人口变异性使气候变化响应的准确检测变得复杂
DOI：
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发表时间：
2016
影响因子：
11.6
通讯作者：
Kevin Bracy Knight
中科院分区：
文献类型：
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作者：
C. McCain;Tim M. Szewczyk;Kevin Bracy Knight
人们急于评估物种对人为气候变化 (CC) 的反应，却低估了种群年际变异 (PV) 的重要性。研究人员认为，无论所考虑物种的潜在种群波动如何，仅靠采样的严格性就可以准确检测反应。通过在真实的、基于经验的 PV 梯度上进行群体模拟，我们发现中等到高的 PV 可能会导致关于 CC 响应的相反和有偏见的结论。在再调查研究中，在 CC 前和 CC 后对建模种群进行采样之间，存在：（i）错误检测种群丰度变化的相反趋势的概率为 50%，检测到无变化的概率几乎为零。 (ii) 在多年的采样中，即使是中等的 PV，也几乎不可能准确检测到种群规模的任何方向性变化。 (iii) 当该物种存在但自然丰度非常低时，检测到种群灭绝的概率高达 50%。 (iv) 在物种分布范围或分布范围边缘的 PV 为中等到高的情况下，存在对分布范围移动或收缩的错误检测的偏差。从本质上讲，群体高峰和低谷的频率和幅度极大地影响了我们的 CC 响应测量的准确性。如果没有相关的人口统计分析和额外的重复采样，具有中等到高 PV 的物种（许多小型脊椎动物、无脊椎动物和一年生植物）对于 CC 来说可能是不准确的“煤矿里的金丝雀”。 PV 的变化可以解释迄今为止检测到的 CC 响应的一些特性，并且迫切需要在 CC 响应的设计和分析中更加仔细地考虑。
The rush to assess species’ responses to anthropogenic climate change (CC) has underestimated the importance of interannual population variability (PV). Researchers assume sampling rigor alone will lead to an accurate detection of response regardless of the underlying population fluctuations of the species under consideration. Using population simulations across a realistic, empirically based gradient in PV, we show that moderate to high PV can lead to opposite and biased conclusions about CC responses. Between pre‐ and post‐CC sampling bouts of modeled populations as in resurvey studies, there is: (i) A 50% probability of erroneously detecting the opposite trend in population abundance change and nearly zero probability of detecting no change. (ii) Across multiple years of sampling, it is nearly impossible to accurately detect any directional shift in population sizes with even moderate PV. (iii) There is up to 50% probability of detecting a population extirpation when the species is present, but in very low natural abundances. (iv) Under scenarios of moderate to high PV across a species’ range or at the range edges, there is a bias toward erroneous detection of range shifts or contractions. Essentially, the frequency and magnitude of population peaks and troughs greatly impact the accuracy of our CC response measurements. Species with moderate to high PV (many small vertebrates, invertebrates, and annual plants) may be inaccurate ‘canaries in the coal mine’ for CC without pertinent demographic analyses and additional repeat sampling. Variation in PV may explain some idiosyncrasies in CC responses detected so far and urgently needs more careful consideration in design and analysis of CC responses.