The blind spots of soil macroecology

Soils are often seen as being locally driven, with many researchers focusing on looking at them through microscope lenses, but nowadays we are discovering new global patterns of soil biodiversity and ecosystem functions and starting to talk about soil biogeography. This global perspective was the main motivation for us to understand where are the limitations of current soil macroecological analysis, and to try to create a roadmap to overcome them.

To do that, we started by uncovering the available literature on soil macroecology. This required a definition of this term, and for us this describes any study that investigated soil biodiversity or soil ecosystem functions at continental scales. The result led to more than 60 different studies with more than 17,000 sampling locations. With these results our initial enthusiasm was high, but it was quickly moderated by the fact that only a very small proportion of these sites actually considers more than one group of soil biodiversity or function. What this means is that we have uncovered thousands of sampling sites with information of soil ecology that cannot be put together in a systematic way. Moreover, we found that most macroecological studies actually only cover less than 50% of all environmental conditions on the planet, which means that many areas of the globe, particularly the ones with more unique ecosystems, fall outside of many of these analyses. One wonders how much diversity is still there waiting to be unearthed.

With this information there are two options: put your head in the sand, or take a stand for what you stand on. We decided to propose a road map that allows scientists, practitioners and policy-makers to act in a constructive way to establish global nature conservation priorities for soils. This roadmap includes four different challenges: i) Legal issues regarding the transport and sharing of soil samples and biological data; ii) Scattered literature and lack of mobilization/ systematization of local studies; iii) Lack of temporally explicit information on soil biodiversity and functions; and iv) Lack of globally distributed expertise, research funding and infrastructure. For each of these challenges we identified potential solutions that can be taken by researchers, institutions or policy-makers. These include the establishment of global multilateral solutions and International Treaties focused on soil biodiversity and ecosystem function research (policy-makers), to address current legal challenges, but also the adoption of available data and methods standards (institutions) to address the lack of data mobilization.

It is also clear that we need to address some of these issues in a global way, particularly how we monitor soil biodiversity and ecosystem functions. This has become the center piece for the constitution of SoilBON (the Global Soil Biodiversity Observation Network), that aims to monitor soil biodiversity across the world in a standardized way, offering a backbone monitoring system that other countries, researchers and practitioners to develop their own monitoring systems and compare results across the world. More detailed information can be found in our paper (open-access) here.

Publication: Guerra, C. A., A. Heintz-Buschart, J. Sikorski, A. Chatzinotas, N. Guerrero-Ramírez, S. Cesarz, L. Beaumelle, M. C. Rillig, F. T. Maestre, M. Delgado-Baquerizo, F. Buscot, J. Overmann, G. Patoine, H. R. P. Phillips, M. Winter, T. Wubet, K. Küsel, R. D. Bardgett, E. K. Cameron, D. Cowan, T. Grebenc, C. Marín, A. Orgiazzi, B. K. Singh, D. H. Wall, & N. Eisenhauer. 2020. Blind spots in global soil biodiversity and ecosystem function research. Nature Communications 11: 3870. https://doi.org/10.1038/s41467-020-17688-2

Dr. Carlos Guerra