Press release: Greater biodiversity leads to higher levels of ecosystem services

Nr. 160/2016 - 18.08.2016

Scientists analyse data from 4,600 plant and animal species in grasslands

(pug) The more it swarms, crawls and flies, the better for humans who benefit from the varied services provided for free by nature. This is the finding of a study by more than 60 researchers, led by the University of Bern and the Senckenberg Biodiversity and Climate Research Centre, with participation from agro-ecologists from the University of Göttingen. A diverse ecosystem populated by many species from all levels of the food chain provides higher levels of ecosystem services, the team reports in Nature. Even rather unpopular insects and invisible soil-dwelling organisms are important in maintaining a wide range of ecosystem services.

Grasslands full of flowers are not only beautiful – they also provide many important services for humans. These include food production, soil development, pest control and climate regulation as well as cultural services such as the use of grassland for recreation. A grassland is also a complex ecosystem containing many species belonging to different levels in the food chain, so called “trophic levels”. Humans are causing declines in biodiversity for many of these groups and evidence from experiments on plants suggests this might threaten ecosystem services. However, studies had not looked at diversity at many trophic levels at the same time.

Therefore, the researchers now studied all groups in a grassland food chain for the first time. They collected data on a total of 4,600 species of animal and plant from nine trophic groups, including often neglected ones such as micro-organisms in the soil and insects that live in the soil or on the plants. The data was collected as part of the “Biodiversity Exploratories”, a programme supported by the Deutsche Forschungsgemeinschaft in 150 grasslands across Germany. The Biodiversity Exploratories constitute the most extensive ecological sampling in Europe.

The scientists found out that each ecosystem service is dependent on at least three trophic groups. “Using trap-nests we recorded cavity-nesting wasps that provision their brood with pest insect larvae. Hence, these wasps act as natural pest control agents and therewith provide a vital ecosystem service in agro-ecosystems,” says agro-ecologist Dr. Catrin Westphal from Göttingen University. The higher the number of species within the group, the more reliably the ecosystem service is provided. In addition, each individual group influences at least one ecosystem service. Therefore, diversity has to be secured in at least three of the analysed groups along the food chain – but since the three groups responsible for a certain ecosystem service are not always the same, biodiversity needs to be protected at all levels of the food chain. Furthermore, the study shows that many insects and soil organisms play a central role, alongside plants, in supplying ecosystem services.

Original publication: Santiago Soliveres et al. Biodiversity at multiple trophic levels is needed for ecosystem multifunctionality. Nature 2016. Doi: 10.1038/nature19092.

Contact:
Dr. Catrin Westphal
University of Göttingen
Faculty of Agricultural Sciences
Department of Agroecology
Grisebachstraße 6, 37077 Göttingen
Phone +49 551 39-22257
Email: catrin.westphal@agr.uni-goettingen.de
Web: http://www.uni-goettingen.de/en/74726.html