Vegetation structure determines the spatial variability of soil biodiversity across biomes

Jorge Durán,Manuel Delgado-Baquerizo

doi:10.1038/s41598-020-78483-z

Jorge Durán, Manuel Delgado-Baquerizo

Open Access

https://doi.org/10.1038/s41598-020-78483-z

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Abstract

The factors controlling the spatial variability of soil biodiversity remain largely undetermined. We conducted a global field survey to evaluate how and why the within-site spatial variability of soil biodiversity (i.e. richness and community composition) changes across global biomes with contrasting soil ages, climates and vegetation types. We found that the spatial variability of bacteria, fungi, protists, and invertebrates is positively correlated across ecosystems. We also show that the spatial variability of soil biodiversity is mainly controlled by changes in vegetation structure driven by soil age and aridity. Areas with high plant cover, but low spatial heterogeneity, were associated with low levels of spatial variability in soil biodiversity. Further, our work advances the existence of significant, undescribed links between the spatial variability of soil biodiversity and key ecosystem functions. Taken together, our findings indicate that reductions in plant cover (e.g., via desertification, increases in aridity, or deforestation), are likely to increase the spatial variability of multiple soil organisms and that such changes are likely to negatively impact ecosystem functioning across global biomes.

Highlights

The factors controlling the spatial variability of soil biodiversity remain largely undetermined
We found that the within-site spatial variability of soil biodiversity is highly variable across biomes (Fig. 1)
Soil invertebrates showed the highest levels of within-site spatial variability, with bacteria showing the lowest levels of variability for belowground richness (Fig. 1c), and with protists, fungi, and bacteria showing similar levels of belowground dissimilarity (Fig. 1d)

Summary

Introduction

The factors controlling the spatial variability of soil biodiversity remain largely undetermined. We are far from understanding how the spatial variability in soil biodiversity is associated with key biotic and abiotic drivers, which limits our capacity to forecast how global environmental changes could alter the spatial distribution of soil organisms, and terrestrial ecosystem functioning. To address these knowledge gaps, we conducted soil and vegetation field surveys in six continents and 87 sites ranging in soil age from hundreds to millions of years, and encompassing a wide range of climatic conditions (tropical, temperate, continental, polar, and arid), vegetation types (grasslands, shrublands, forests, and croplands), and origins (volcanic, sedimentary, dunes, and glaciers) (Tables S1 and S2). How and why (i.e. climate, soil properties and plant attributes) the spatial variability of the soil biodiversity changes in ecosystems across the planet with contrasting climate, vegetation and soil age

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Conclusion