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科学家揭示全球脊椎动物种群数量的变化趋势
2020-11-19 16:11

加拿大麦吉尔大学Brian Leung团队在研究中取得进展。他们的研究揭示全球脊椎动物呈现聚集与毁灭性减少。这一研究成果于2020年11月18日在线发表在国际学术期刊《自然》上。

例如,之前的分析估计,自1970年以来脊椎动物的平均下降幅度超过50%(“生命星球指数” )。但是,研究人员发现,这一估计是由不到3%的脊椎动物种群得出的;如果将这些极度下降的种群排除在外,全球趋势将转向增长。全球平均趋势对异常值的灵敏性表明,需要更多的信息指标。研究人员提出了一种替代方法,该方法可以识别出在统计上与大多数种群趋势不同的极端下降(或增加)的集群。研究表明,在《生命星球指数》的生物分类-地理系统中,有16个系统包含极端下降的集群(占总数的1%;这些极端下降不成比例地出现在较大的动物中),还有7个系统包含极端增长的集群(约占总数的0.4%) 。所有系统中其余98.6%的种群不具有平均全球趋势。

然而,单独分析时,三个系统均表现出显著(全部在印度-太平洋地区)的下降,其中七个系统存在明显下降,且不确定性较低(主要是爬行动物和两栖动物类)。对极端集群的研究从根本上改变了对全球脊椎动物变化趋势的理解,这有助于确定保护工作的优先次序。

研究人员表示,最近的研究表明全球脊椎动物种群呈现出毁灭性下降。但是,将许多趋势精炼成全球平均指数会掩盖可以为保护措施提供信息并且对分析决策起作用的变化。

附:英文原文

Title: Clustered versus catastrophic global vertebrate declines

Author: Brian Leung, Anna L. Hargreaves, Dan A. Greenberg, Brian McGill, Maria Dornelas, Robin Freeman

Issue&Volume: 2020-11-18

Abstract: Recent analyses have reported catastrophic global declines in vertebrate populations1,2. However, the distillation of many trends into a global mean index obscures the variation that can inform conservation measures and can be sensitive to analytical decisions. For example, previous analyses have estimated a mean vertebrate decline of more than 50% since 1970 (Living Planet Index2). Here we show, however, that this estimate is driven by less than 3% of vertebrate populations; if these extremely declining populations are excluded, the global trend switches to an increase. The sensitivity of global mean trends to outliers suggests that more informative indices are needed. We propose an alternative approach, which identifies clusters of extreme decline (or increase) that differ statistically from the majority of population trends. We show that, of taxonomic–geographic systems in the Living Planet Index, 16 systems contain clusters of extreme decline (comprising around 1% of populations; these extreme declines occur disproportionately in larger animals) and 7 contain extreme increases (around 0.4% of populations). The remaining 98.6% of populations across all systems showed no mean global trend. However, when analysed separately, three systems were declining strongly with high certainty (all in the Indo-Pacific region) and seven were declining strongly but with less certainty (mostly reptile and amphibian groups). Accounting for extreme clusters fundamentally alters the interpretation of global vertebrate trends and should be used to help to prioritize conservation efforts. In the geographically and taxonomically divided systems of vertebrates in the Living Planet Index, a small percentage of clusters showed extreme declines or increases, whereas most vertebrate populations across all systems showed no mean global trend.

DOI: 10.1038/s41586-020-2920-6

Source: https://www.nature.com/articles/s41586-020-2920-6

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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