New insights into the natural history of soil biodiversity

The study published today in the prestigious journal Proceedings of the National Academy of Sciences provides critical insights on the factors that control changes in the biodiversity of soil bacteria, fungi, protists and invertebrates over centuries to millennia, and indicate that these changes in soil biodiversity are driven by changes in plant cover and acidification during ecosystem development.

Soil microbes and animals, from the smallest soil bacteria to the largest earthworms, provide a vast variety of ecosystem services, which include, for instance, waste and toxin recycling, climate regulation, and nutrient availability for crop raising. Soil organisms are, therefore, essential for human well-being and ecosystem sustainability. “Compared with plants, where most investigations are focused today, soil animals and microbes are by far the most abundant and diverse organisms on Earth. Even so, we know almost nothing about their natural history. How does soil biodiversity change over millions of years in terrestrial ecosystems? Are there any global ecological patterns associated with these changes? These are the questions that we posed in this project,” says Manuel Delgado Baquerizo, the main author of this paper and a Marie Curie researcher at Rey Juan Carlos University in Spain.

Two major ecological patterns explain the changes in soil biodiversity over centuries to millennia. In less productive ecosystems, increases in soil biodiversity followed increases in plant cover, which provide food for soil microbes and animals. In more productive ecosystems, however, where resource availability is more abundant, acidification during soil development was often associated with declines in soil biodiversity. Interestingly, these patterns are different from those reported for plant communities. “Results from this study provide novel and very interesting findings that provide a better understanding of the natural history of soil biodiversity and associated ecosystem functions along ecosystem development, a critical ecological process” indicated Prof. Fernando T. Maestre from URJC, lead of the Dryland Ecology and Global Change Lab and co-author in this study.

This study took place within the framework of the Marie Skłodowska-Curie Action CLIMIFUN which aims to evaluate the changes in soil organisms and functions during ecosystem development. To achieve these results, the researchers conducted a soil survey over almost one hundreds terrestrial ecosystems for which soil age is known, and which includes a wide variety of ecosystem types from deserts and polar ecosystems to temperate and tropical forests. These soils were analyzed in the URJC and University of Colorado-Boulder where the main author spent two years as a postdoctoral researcher in the Fierer lab at the CU Boulder. “Our study is fundamental to understand the development of soil biodiversity in a drier and hotter world” said Delgado Baquerizo.

Reference

Delgado-Baquerizo, M. et al. Changes in belowground biodiversity during ecosystem development. Proceedings of the National Academy of Sciences of the United States of America.

Main photo: Victor M. Peña Ramírez.