First Global-Scale Assessment Of Biodiversity Beneath Our Feet

As part of the Global Litter Invertebrate Decomposition Experiment (GLIDE), last August and September the researchers placed mesh bags of leaf litter on the ground of diverse ecosystems, from tropical to boreal forests, and from to savannahs to arctic tundra. Over the next two months they will retrieve a subset of these bags for analysis of global patterns of decomposition and the species involved.

The Chair of GLIDE, Dr. Diana Wall of Colorado State University, USA, expects the study to significantly advance understanding of large-scale distributions of fauna that dwell in soil and litter. Even at small scales, biodiversity in soils and litter is poorly known.

There is not one experimental plot, anywhere in the world, for which all species of soil and litter fauna have been described. The dearth of information on belowground species is partly because of their sheer abundance and diversity.

“The species diversity of fauna in litter and soil is likely to be orders of magnitude greater than the more familiar biodiversity aboveground,” says Wall. “Furthermore, there may be hundreds of species and thousands of individuals in a handful of soil or litter. Collecting and identifying such large numbers of species poses an enormous challenge to soil taxonomists.”

Additionally, Wall explains, the majority of these species are not visible to the naked eye since they live in dark underground habitats and many are microscopic. As a result, it is estimated that for many soil and litter taxonomic groups less than 10 percent of species have been described scientifically.

Despite limited knowledge about the identity of individual species of soil and litter biota, soil biologists know that assemblages of the species play crucial roles in the functioning of ecosystems, including decomposing organic matter and recycling nutrients to the soil.

However, lack of information on how the identity and diversity of species varies across habitats and influences ecosystem processes limits scientists’ ability to assess how changes in habitats, for example associated with deforestation and climate change, may alter communities of litter fauna and vital ecosystem processes.