Fewer Diversity, Fewer Benefits

If the diversity of species in an ecosystem is reduced, human beings can draw fewer benefits from it. An international team including participation from Helmholtz Zentrum München has now proven this postulate experimentally. Their results have been published in Nature.

ecosystem
Site at the "Schwäbischen Alb". Photo: Barbara Stempfhuber / HMGU

Back in the year 2000 there was success in verifying important influencing variables which lead to a decline in the global diversity*. This includes changes in land management, the climate change, the nitrogen load in stretches of water, invasion by new plant species (neophytes) and the increase in the concentration of carbon dioxide in the atmosphere.

An international research team with the participation of the Helmholtz Zentrum München has now demonstrated relationships between the diversity and the ecosystem services** of a site.

Adapting usage strategies

“This has always been postulated, but it has never been possible to prove it,” explained Prof. Dr. Michael Schloter, manager of the independent Environmental Genomics Department (EGEN) at Helmholtz Zentrum München.

For the current study 150 locations in Germany were examined. Here, researchers recorded the diversity not just in one dimension, but on completely different levels. Until now the diversity of terrestrial ecosystems has mainly been linked to that of plant diversity. Other groups, such as microorganisms, soil animals and insects have largely been unaddressed. The study shows particularly how important these organisms are for the examined ecosystem services. “Obviously, ecosystems are controlled by the interaction of different organisms so that each trophic level*** is significant for the functioning of the system,” says Schloter. If biodiversity declined, putative ecosystem services would be also reduced.

“This means that biodiversity not only has a cultural aspect when the intention is to retain it, but rather has very practical benefits for human beings,” adds Barbara Stempfhuber from EGEN. She demands: “Usage strategies for ecosystems have to be adapted accordingly.” Furthermore, she says that it is also important to consider the biodiversity during the socio-economic assessment of any measures taken. 

In the next step the researchers will examine whether relationships also occur between ecosystem services and diversity in other ecosystems. Schloter: “Also, the human being constitutes an ecosystem. We are asking ourselves by how much does a high diversity, for example, protect the intestinal microbiome from diseases.”