瑞英兩國科學(xué)家近日研究發(fā)現(xiàn)，生物多樣性的喪失給食物的生產(chǎn)、水質(zhì)量以及二氧化碳的水平帶來的影響要比之前人們估計的要嚴(yán)重的多,。這一研究將有助于為今后環(huán)境政策的制定提供指導(dǎo),。相關(guān)論文發(fā)表在7月12日的《自然》雜志上,。
進行該項研究的是瑞士蘇黎世大學(xué)的AndyHector和英國牛津大學(xué)的RobertBagchi,。他們通過一種新方法分析了來自歐洲草原的數(shù)據(jù)，結(jié)果發(fā)現(xiàn),，牽涉的生態(tài)過程越多,，維持這些生態(tài)過程所需的物種也會相應(yīng)增加。
這與以前的一些研究結(jié)果很不相同,。Hector說：“之前的一些分析聚焦范圍都很窄,，從而得出結(jié)論認(rèn)為，對一個生態(tài)系統(tǒng)重要的物種也能在其它所有方面起作用,。而事實并不是這樣,。”
此次的研究首次證實，一個地方的不同生態(tài)系統(tǒng)過程會受到不同物種群的影響,。英國謝菲爾德大學(xué)的OwenPetchey說：“人們過去經(jīng)常談到這些,，但一直沒有相關(guān)證據(jù)支持。這次的研究表明,，對一個全能性生態(tài)系統(tǒng)來說,，最大數(shù)量的物種必須得到保護。生物多樣性是必須的,，人類依賴生態(tài)系統(tǒng)提供很多東西,。這一研究將在很大程度上影響政策的制定。”
1997年的一份評估報告認(rèn)為,，一個包括生物分解,、土壤形成、營養(yǎng)和水分循環(huán)以及植物生長的生態(tài)系統(tǒng)過程每年可提供給人類的價值高達33萬億美元,。而2005年的聯(lián)合國報告指出,，過去50年人類對生物多樣性造成的損害比其它任何時期都要嚴(yán)重。所以,，只有及時扼住惡化的趨勢,，人類才能繼續(xù)享受這一大自然的饋贈。（科學(xué)網(wǎng)梅進/編譯）
原始出處:
Letter
Nature 448, 188-190 (12 July 2007) | doi:10.1038/nature05947; Received 13 April 2007; Accepted 15 May 2007
Biodiversity and ecosystem multifunctionality
Andy Hector1 & Robert Bagchi1,2
Institute of Environmental Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
Present address: Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, UK.
Correspondence to: Andy Hector1 Correspondence and requests for materials should be addressed to A.H. (Email: [email protected]).
Biodiversity loss can affect ecosystem functions and services1, 2, 3, 4. Individual ecosystem functions generally show a positive asymptotic relationship with increasing biodiversity, suggesting that some species are redundant5, 6, 7, 8. However, ecosystems are managed and conserved for multiple functions, which may require greater biodiversity. Here we present an analysis of published data from grassland biodiversity experiments9, 10, 11, and show that ecosystem multifunctionality does require greater numbers of species. We analysed each ecosystem function alone to identify species with desirable effects. We then calculated the number of species with positive effects for all possible combinations of functions. Our results show appreciable differences in the sets of species influencing different ecosystem functions, with average proportional overlap of about 0.2 to 0.5. Consequently, as more ecosystem processes were included in our analysis, more species were found to affect overall functioning. Specifically, for all of the analysed experiments, there was a positive saturating relationship between the number of ecosystem processes considered and the number of species influencing overall functioning. We conclude that because different species often influence different functions, studies focusing on individual processes in isolation will underestimate levels of biodiversity required to maintain multifunctional ecosystems.
