With the recent focus on climate change at COP-26, the spotlight has, understandably, temporarily moved off the myriad other environmental challenges humanity faces—many of them interlinked. Among these are the ongoing loss of biological diversity and threats to soil fertility. In PNAS, Furey and Tilman (1) present results from a long-term field experiment that demonstrates the importance of plant diversity for healthy soils.
Although the issue dates back to Darwin (2), ecologists only really started to intensively study the importance of biodiversity for ecosystem functioning in the early 1990s—an idea that was initially controversial and heavily debated until a series of review and consensus pieces started to provide some clarity and agreement (3⇓⇓⇓⇓–8). One of the key approaches employed was the use of biodiversity experiments: interventions that directly manipulate numbers and types of species while monitoring the response of ecosystem functioning—changes in the stocks and flows of energy and matter. These biogeochemical processes—like primary productivity—underpin human societies by providing a multitude of ecosystem services (or “nature’s contributions to people”), such as the provision of food, materials, and clean water; the sequestration of atmospheric carbon; and the generation of healthy soils. Furey and Tilman (1) present results from the longest-running biodiversity experiment (it will soon celebrate its 30th anniversary in 2024) that show how ecologically diverse mixtures of plant species can generate soils that are richer in essential plant nutrients and more productive in plant biomass and that store more carbon.
To manipulate plant diversity at their study system in the prairies of the Cedar Creek Ecosystem Science Reserve in Minnesota, the preexisting seed bank had to be removed so that designed mixtures of plants could be sown that experimentally varied numbers and types of species. While it has its drawbacks, the removal of the …