Palmer Georgina, Platts Philip J, Brereton Tom, Chapman Jason W, Dytham Calvin, Fox Richard, Pearce-Higgins James W, Roy David B, Hill Jane K, Thomas Chris D
Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK.
Philos Trans R Soc Lond B Biol Sci. 2017 Jun 19;372(1723). doi: 10.1098/rstb.2016.0144.
Extreme climatic events could be major drivers of biodiversity change, but it is unclear whether extreme biological changes are (i) individualistic (species- or group-specific), (ii) commonly associated with unusual climatic events and/or (iii) important determinants of long-term population trends. Using population time series for 238 widespread species (207 Lepidoptera and 31 birds) in England since 1968, we found that population 'crashes' (outliers in terms of species' year-to-year population changes) were 46% more frequent than population 'explosions'. (i) Every year, at least three species experienced extreme changes in population size, and in 41 of the 44 years considered, some species experienced population crashes while others simultaneously experienced population explosions. This suggests that, even within the same broad taxonomic groups, species are exhibiting individualistic dynamics, most probably driven by their responses to different, short-term events associated with climatic variability. (ii) Six out of 44 years showed a significant excess of species experiencing extreme population changes (5 years for Lepidoptera, 1 for birds). These 'consensus years' were associated with climatically extreme years, consistent with a link between extreme population responses and climatic variability, although not all climatically extreme years generated excess numbers of extreme population responses. (iii) Links between extreme population changes and long-term population trends were absent in Lepidoptera and modest (but significant) in birds. We conclude that extreme biological responses are individualistic, in the sense that the extreme population changes of most species are taking place in different years, and that long-term trends of widespread species have not, to date, been dominated by these extreme changes.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'.
极端气候事件可能是生物多样性变化的主要驱动因素，但尚不清楚极端生物变化是否为：（i）个体性的（特定物种或类群的）；（ii）通常与异常气候事件相关；和/或（iii）长期种群趋势的重要决定因素。利用自1968年以来英格兰238种广泛分布物种（207种鳞翅目昆虫和31种鸟类）的种群时间序列，我们发现种群“崩溃”（就物种逐年种群变化而言的异常值）比种群“爆发”频繁46%。（i）每年至少有三个物种经历种群数量的极端变化，在44年中的41年里，一些物种经历种群崩溃，而其他物种同时经历种群爆发。这表明，即使在同一大类分类群中，物种也表现出个体动态，很可能是由它们对与气候变异性相关的不同短期事件的反应所驱动。（ii）44年中有6年出现经历极端种群变化的物种显著过多的情况（鳞翅目昆虫有5年，鸟类有1年）。这些“一致年份”与气候极端年份相关，这与极端种群反应和气候变异性之间的联系一致，尽管并非所有气候极端年份都会产生过多的极端种群反应。（iii）鳞翅目中极端种群变化与长期种群趋势之间没有联系，而在鸟类中这种联系较为微弱（但显著）。我们得出结论，极端生物反应是个体性的，因为大多数物种的极端种群变化发生在不同年份，而且迄今为止，广泛分布物种的长期趋势尚未由这些极端变化主导。本文是主题为“对极端气候事件的行为、生态和进化反应”特刊的一部分。
