北美地區(qū)的雪兔－猞猁種群數(shù)量10年周期性波動(dòng)一直是種群生態(tài)學(xué)中研究的一個(gè)熱點(diǎn),，并且在生態(tài)學(xué)教科書(shū)中一直被用作獵物-捕食者相互作用形成種群周期振蕩的經(jīng)典案例,。中科院動(dòng)物研究所農(nóng)業(yè)動(dòng)物生態(tài)研究組嚴(yán)川等通過(guò)分析長(zhǎng)期數(shù)據(jù)發(fā)現(xiàn)：一,，與傳統(tǒng)的獵物－捕食模型不同,，雪兔與猞猁之間存在非對(duì)稱(chēng)性的獵物－捕食者效應(yīng),，即雪兔對(duì)猞猁為直接正作用,，而猞猁對(duì)雪兔的負(fù)作用有兩年時(shí)滯,；二,，密度制約及獵物－捕食者作用僅能產(chǎn)生阻尼式振蕩,，而氣候的驅(qū)動(dòng)對(duì)于周期性波動(dòng)的產(chǎn)生及持續(xù)具有重要作用；三,，溫度沒(méi)有直接作用,，北半球溫度與北大西洋濤動(dòng)指數(shù)通過(guò)降雨及降雪負(fù)作用于猞猁種群，而南方濤動(dòng)指數(shù)通過(guò)降雨正作用猞猁種群,；四,，氣溫變暖可能導(dǎo)致近期猞猁周期性波動(dòng)減弱或消失。
該研究結(jié)果說(shuō)明：獵物-捕食者相互作用不是形成種群周期振蕩的充分必要條件,，氣候?qū)ΨN群周期性波動(dòng)起著不可或缺的作用,；全球氣候變暖可導(dǎo)致種群周期波動(dòng)消失（生物谷Bioon.com）。
生物谷推薦的英文摘要
Global Change Biology doi: 10.1111/gcb.12321
Linking climate change to population cycles of hares and lynx
Yan C,， Stenseth NC,， Krebs CJ， Zhang Z
The classic 10-year population cycle of snowshoe hares (Lepus americanus,， Erxleben 1777) and Canada lynx (Lynx canadensis,， Kerr 1792) in the boreal forests of North America has drawn much attention from both population and community ecologists worldwide； however,， the ecological mechanisms driving the 10-year cyclic dynamic pattern are not fully revealed yet. In this study,， by the use of historic fur harvest data， we constructed a series of generalized additive models to study the effects of density dependence,， predation,， and climate (both global climate indices of North Atlantic Oscillation index (NAO)， Southern Oscillation index (SOI) and northern hemispheric temperature (NHT) and local weather data including temperature,， rainfall,， and snow). We identified several key pathways from global and local climate to lynx with various time lags： rainfall shows a negative， and snow shows a positive effect on lynx,； NHT and NAO negatively affect lynx through their positive effect on rainfall and negative effect on snow,； SOI positively affects lynx through its negative effect on rainfall. Direct or delayed density dependency effects， the prey effect of hare on lynx and a 2-year delayed negative effect of lynx on hare (defined as asymmetric predation) were found. The simulated population dynamics is well fitted to the observed long-term fluctuations of hare and lynx populations. Through simulation,， we find density dependency and asymmetric predation,， only producing damped oscillation， are necessary but not sufficient factors in causing the observed 10-year cycles,； while extrinsic climate factors are important in producing and modifying the sustained cycles. Two recent population declines of lynx (1940-1955 and after 1980) were likely caused by ongoing climate warming indirectly. Our results provide an alternative explanation to the mechanism of the 10-year cycles,， and there is a need for further investigation on links between disappearance of population cycles and global warming in hare-lynx system.
