Extreme temperature events alter demographic rates，relative fitness，and community structure

Gang Ma，Volker H. W. Rudolf，Chun-sen Ma*

1. Climate Change Biology Research Group，State Key Laboratory for Biology of Plant Diseases and Insect Pests，Institute of Plant Protection，Chinese Academy of Agricultural Sciences，Beijing，China

2. Department of Ecology and Evolutionary Biology，Rice University，Houston，TX，USA

Extreme temperature events alter demographic rates，relative fitness，and community structure

Gang Ma1，Volker H. W. Rudolf2，Chun-sen Ma1*

1. Climate Change Biology Research Group，State Key Laboratory for Biology of Plant Diseases and Insect Pests，Institute of Plant Protection，Chinese Academy of Agricultural Sciences，Beijing，China

2. Department of Ecology and Evolutionary Biology，Rice University，Houston，TX，USA

學(xué)科：植物保護(hù)

推薦專家：馬春森研究員（中國農(nóng)業(yè)科學(xué)院植物保護(hù)研究所）

推薦論文：Leah Li，Rebecca Hardy，Diana Kuh，et al. Extreme temperature events alter demographic rates，relative fitness，and community structure［J］. Global Change Biology，2015，21（5）： 1794-1808

·專家點評·

氣候變化導(dǎo)致極端高溫事件頻發(fā)，小型害蟲世代歷期短，繁殖快，為害嚴(yán)重，但對極端高溫事件十分敏感。小麥蚜蟲是世界性的麥類作物的重大害蟲，主要由麥長管蚜、麥二叉蚜和禾谷縊管蚜等3個物種組成。作者首先在實驗室模擬極端高溫事件試驗中發(fā)現(xiàn)，高溫強(qiáng)度和頻率增加可導(dǎo)致禾谷縊管蚜的適合度升高，而麥長管蚜和麥二叉蚜的適合度則降低。這意味著氣候變暖條件下的極端高溫事件可能導(dǎo)致麥蚜優(yōu)勢種發(fā)生演替。進(jìn)一步采用田間模擬增溫試驗，為期6年的田間種群系統(tǒng)調(diào)查證實了極端高溫事件改變了3種麥蚜的群落結(jié)構(gòu)和相對優(yōu)勢度，禾谷縊管蚜在極端高溫事件頻發(fā)的年份相對優(yōu)勢度較高；而麥長管蚜和麥二叉蚜則在極端高溫事件發(fā)生較少的年份相對優(yōu)勢度較高。全球范圍內(nèi)的數(shù)據(jù)分析（meta-analysis）也在大尺度空間上一致指向，麥長管蚜和麥二叉蚜在極端高溫事件頻率較小的中高緯度麥區(qū)為優(yōu)勢種；而禾谷縊管蚜在極端高溫事件發(fā)生概率較大的低緯度地區(qū)占據(jù)明顯優(yōu)勢。

全球氣候變化給生物帶來了新的選擇壓力，然而物種間對這種選擇壓力的非對稱響應(yīng)，可能導(dǎo)致物種間相對優(yōu)勢度和群落結(jié)構(gòu)的改變。作者以3種麥蚜為模式系統(tǒng)，闡明了全球氣候變化導(dǎo)致的極端高溫事件幅度和頻率增加與農(nóng)業(yè)害蟲群落物種間相對優(yōu)勢度和群落結(jié)構(gòu)之間的關(guān)系，證實了全球氣候變化打破農(nóng)業(yè)害蟲群落原有的平衡，導(dǎo)致了害蟲群落結(jié)構(gòu)變化和優(yōu)勢種演替，在害蟲氣候變化生物學(xué)上具有創(chuàng)新意義。本研究采用的室內(nèi)、田間控制模擬，田間觀測和全球數(shù)據(jù)元分析的綜合研究方法，在個體和群落的水平上研究害蟲氣候生物學(xué)方法上，具有重要參考價值。研究得出的結(jié)果，對提高氣候變化條件下害蟲預(yù)測水平，制定科學(xué)應(yīng)對氣候變化的害蟲防治策略具有重要應(yīng)用價值。

The frequency and magnitude of extreme events are predicted to increase under future climate change. Despite recent advancements，we still lack a detailed understanding of how changes in the frequency and amplitude of extreme climate events are linked to the temporal and spatial structure of natural communities. To answer this question，we used a combination of laboratory experiments，field experiments，and analysis of multi-year field observations to reveal the effects of extreme high temperature events on the demographic rates and relative dominance of three co-occurrence aphid species which differ in their transmission efficiency of different agricultural pathogens. We then linked the geographical shift in their relative dominance to frequent extreme high temperatures through a meta-analysis. We found that both frequency and amplitude of extreme high temperatures altered demographic rates of species. However，these effects were speciesspecific. Increasing the frequency and amplitude of extreme temperature events altered which species had the highest fitness. Importantly，this change in relative fitness of species was consistent with significant changes in the relative dominance of species in natural communities in a 1 year long field heating experiment and 6 year long field survey of natural populations. Finally，at a global spatial scale，we found the same relationship between relative abundance of species and frequency of extreme temperatures. Together，our results indicate that changes in frequency and amplitude of extreme high temperatures can alter the temporal and spatial structure of natural communities，and that these changes are driven by asymmetric effects of high temperatures on the demographic rates and fitness of species. They also highlight the importance of understanding how extreme events affect the life-history of species for predicting the impacts of climate change at the individual and community level，and emphasize the importance of using a broad range of approaches when studying climate change.

climate change； community structure； extreme climatic event； heat stress； heat waves； insects； relative dominance； temperature extremes

責(zé)任編輯：王帥帥

Correspondence： Chun-sen Ma，tel.fax： +86 10 62811430，E-mail： machunsen@caas.cn