8.10.2013: Forschung international

Verlust der biologischen Vielfalt hat einen Einfluss auf die Menschheit

La perte de biodiversité a un impact sur l’humanité


Bradley J. Cardinale et al.

Zwanzig Jahre nach dem Erdgipfel haben Wissenschaftler den Stand des Wissens über den Einfluss des Verlustes von Biodiversität auf Ökosystemfunktionen und auf die gelieferten Güter und Dienstleistungen bewertet. Man ist sich unter anderem darin einig, dass der Einfluss von Biodiversität auf Ökosystemprozesse nicht linear ist. Die Herausforderung besteht heute darin, die gewonnenen Erkenntnisse zu nutzen.

Vingt ans après le Sommet de la Terre, des scientifiques ont passé en revue l’état des connaissances sur l’influence de la diminution de la biodiversité sur les fonctions des écosystèmes et sur les biens et services qu’ils livrent.
Il existe entre autre un consensus sur le fait que l’influence de la biodiversité sur les processus écosystémiques est non-linéaire. Le défi aujourd’hui est d’utiliser les connaissances acquises.



The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists and fungi inhabit the Earth. So, too, do 7 billion people. Two decades ago, at the first Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper.
The balance of evidence that has accrued over the last two decades justifies the following statements about how biodiversity loss has an impact on the functioning of ecosystems.
1. There is now unequivocal evidence that biodiversity loss reduces the efficiency by which ecological communities capture biologically essential resources, produce biomass, decompose and recycle biologically essential nutrients.
2. There is mounting evidence that biodiversity increases the stability of ecosystem functions through time.
3. The impact of biodiversity on any single ecosystem process is nonlinear and saturating, such that change accelerates as biodiversity loss increases.
4. Diverse communities are more productive because they contain key species that have a large influence on productivity, and differences in functional traits among organisms increase total resource capture.
5. Loss of diversity across trophic levels has the potential to influence ecosystem functions even more strongly than diversity loss within trophic levels.
6. Functional traits of organisms have large impacts on the magnitude of ecosystem functions, which give rise to a wide range of plausible impacts of extinction on ecosystem function.
In addition to the consensus statements above, data published in the past few years have revealed four emerging trends that are changing the way to view the functional consequences of biodiversity loss.
1. The impacts of diversity loss on ecological processes might be sufficiently large to rival the impacts of many other global drivers of environmental change.
2. Diversity effects grow stronger with time, and may increase at larger spatial scales.
3. Maintaining multiple ecosystem processes at multiple places and times requires higher levels of biodiversity than does a single process at a single place and time.
4. The ecological consequences of biodiversity loss can be predicted from evolutionary history.
Over the past 20 years, researchers have developed a rigorous understanding of the services that natural and modified ecosystems provide to society.
1. There is now sufficient evidence that biodiversity per se either directly influences (experimental evidence) or is strongly correlated with (observational evidence) certain provisioning and regulating services.
2. For many of the ecosystem services reviewed, the evidence for effects of biodiversity is mixed, and the contribution of biodiversity per se to the service is less well defined.
3. For many services, there are insufficient data to evaluate the relationship between biodiversity and the service.
4. For a small number of ecosystem services, current evidence for the impact of biodiversity runs counter to expectations.
The scientific consensus that has emerged over 20 years of biodiversity research has been reported, to help orient the next generation of research on the links between biodiversity and the benefits ecosystems provide to humanity. One of the greatest challenges now is to use what we have learned to develop predictive models that are founded on empirically quantified ecological mechanisms; that forecast changes in ecosystem services at scales that are policy-relevant; and that link to social, economic and political systems. Without an understanding of the fundamental ecological processes that link biodiversity, ecosystem functions and services, attempts to forecast the societal consequences of diversity loss, and to meet policy objectives, are likely to fail.


Keywords:
Ökosystemleistungen, Forschung, Science-Policy

Art der Publikation:
Fachpublikation

Literatur:
Cardinale B. J. (2012). Biodiversity loss and its impact on humanity. Nature 486, 59-67

Kontaktadresse:
B. J. Cardinale
School of natural resources and environment
University of Michigan
Ann Arbor
Michigan 48109, USA

bradcard@umich.edu


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