Complex food webs ensure the proper functioning of ecosystems

The research team analysed 318 datasets on food webs from marine, freshwater and terrestrial ecosystems, which documented numerous species and their feeding relationships. In doing so, it investigated how species from different levels of the food web – from plants and algae at the base, through herbivores, to predators at higher levels – interact, and how their diversity affects key ecosystem functions. Unlike many earlier studies, which focused on individual groups of organisms or just a few systems, this study is the first to examine the complexity of entire food webs on the largest scale to date.

The results show that increased biodiversity leads to an increase in the productivity of ecosystems. The diversity of predatory species is particularly important in this regard. They fulfil different ecological roles and complement one another in their functions. This strengthens processes such as biological pest control, energy flows and the stability of ecosystems. It is therefore not just the number of species that is crucial, but also the diversity of their interactions within the food web.

The study was carried out as part of a global research network led by the University of Waikato (New Zealand) and the German Centre for Integrative Biodiversity Research (iDiv) Halle–Jena–Leipzig.

“The findings highlight how important it is not to focus biodiversity conservation solely on individual species. It is equally important to understand and preserve the ecological relationships between them, as these form the basis of functioning and resilient ecosystems,” explains Dr David Ott from the LIB.

In particular, the loss of predatory species can have far-reaching consequences for natural processes. In addition to species diversity, greater consideration should therefore be given to the complexity of ecological networks in the context of biodiversity conservation.

Publication:

Barnes, A.D., Brose, U., Eisenhauer, N. et al. Food web complexity underlies biodiversity effects on ecosystem functioning. Nature (2026). https://doi.org/10.1038/s41586-026-10710-5

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