Archive and refugia of soil organisms: applying a pedodiversity framework for the conservation of biological and non-biological heritages.
The pedosphere is a part of our natural heritage. Soils should be considered both for their biological and for their geological resources. During the Anthropocene, human activities have dramatically changed the land surface and remodified soil cover, resulting in many natural pedotaxa being at risk of extinction. Recently, biogeographers and ecologists recognized that numerous biotaxa should be considered as edaphic endemisms, and as a consequence, in situ soil preservation is important relative to both its biological and geological value. This contribution discusses the similarity and differences between biodiversity and pedodiversity and proposes using pedodiversity as a surrogate measure of above-ground biodiversity and an indicator of below-ground biodiversity. Another objective is to explore the relevance of soil diversity to soil ecology by illustrating how the analysis of pedotaxa and their genetic soil horizons can be applied in conservation biology. To preserve biological and geological heritage inherent to the pedosphere, we propose to design a network of soil reserves. The proposed network could also be an efficient way to preserve soil characteristics and qualities of undisturbed soils that would become benchmarks for soil monitoring programs. Synthesis and applications. The coincidence between patterns of biodiversity and pedodiversity offers a new and unexplored direction for understanding the genesis of biological and non-biological assemblages and the spatial patterns of soils and living organisms. Pedodiversity can be used as a practical surrogate indicator of soil diversity. We provide a pedodiversity framework for the design of a network of soil reserves for the preservation and monitoring of soil biodiversity. This new framework could contribute toward the development of a unified theory of natural diversity and to understanding the role of the pedosphere in the provision of ecosystem services.