Davis Kristin P, Sofaer Helen R, Pejchar Liba
Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA.
Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA.
Glob Chang Biol. 2023 Jun;29(11):2999-3009. doi: 10.1111/gcb.16700. Epub 2023 Apr 5.
While rare species are vulnerable to global change, large declines in common species (i.e., those with large population sizes, large geographic distributions, and/or that are habitat generalists) also are of conservation concern. Understanding if and how commonness mediates species' responses to global change, including land cover change, can help guide conservation strategies. We explored avian population responses to land cover change along a gradient from common to rare species using avian data from the North American Breeding Bird Survey (BBS) and land cover data from the National Land Cover Database for the conterminous United States. Specifically, we used generalized linear mixed effects models to ask if species' commonness affected the relationship between land cover and counts, using the initial amount of and change in land cover surrounding each North American BBS route from 2001 to 2016. We quantified species' commonness as a continuous metric at the national scale using the logarithm (base 10) of each species' total count across all routes in the conterminous United States in 2001. For our focal 15-year period, we found that higher proportions of initial natural land cover favored (i.e., were correlated with higher) counts of rare but not common species. We also found that commonness mediated how change in human land cover, but not natural land cover, was associated with species' counts at the end of the study period. Increases in developed lands did not favor counts of any species. Increases in agriculture and declines in pasture favored counts of common but not rare species. Our findings show a signal of commonness in how species respond to a major dimension of global change. Evaluating how and why commonness mediates species' responses to land cover change can help managers design conservation portfolios that sustain the spectrum of common to rare species.
虽然珍稀物种易受全球变化影响，但常见物种（即种群数量大、地理分布广和/或为栖息地泛化种的物种）的大幅减少也值得关注。了解常见性是否以及如何影响物种对全球变化（包括土地覆盖变化）的反应，有助于指导保护策略。我们利用来自北美繁殖鸟类调查（BBS）的鸟类数据以及美国本土国家土地覆盖数据库的土地覆盖数据，探讨了从常见到珍稀物种梯度上鸟类种群对土地覆盖变化的反应。具体而言，我们使用广义线性混合效应模型，通过2001年至2016年每条北美BBS路线周围土地覆盖的初始量和变化，来研究物种的常见性是否会影响土地覆盖与计数之间的关系。我们将物种的常见性量化为全国范围内的连续指标，使用2001年美国本土所有路线上每个物种总数的以10为底的对数。在我们关注的15年期间，我们发现初始自然土地覆盖比例较高有利于（即与较高的）珍稀但非常见物种的计数。我们还发现，常见性介导了人类土地覆盖的变化（而非自然土地覆盖的变化）与研究期末物种计数之间的关联。开发用地的增加对任何物种的计数都没有好处。农业用地的增加和牧场面积的减少有利于常见但非珍稀物种的计数。我们的研究结果显示了物种对全球变化一个主要方面的反应中存在常见性信号。评估常见性如何以及为何介导物种对土地覆盖变化的反应，有助于管理者设计保护方案，以维持从常见到珍稀物种的多样性。
