During November and December scientists at 32 sites in 20 countries will gather field collections as part of a global experiment to survey biodiversity in litter (the layer of plant debris on the soil surface) and its role in an important ecosystem function, decomposition.
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.
“The enormous resources required to survey belowground biodiversity has prohibited assessments across multiple biomes in the past,” Wall explains, but she and her colleagues are utilizing creative approaches to make this first global scale assessment of litter biodiversity possible.
Firstly, they are benefiting from the participation of established international networks that provide extensive geographical coverage, baseline data, expertise and infrastructure. Participating networks include the Canadian Intersite Decomposition Experiment (CIDET), International Long-Term Ecological Research (ILTER) program, Long-Term Intersite Decomposition Experiment Team (LIDET) and the Tropical Soil Biology and Fertility (TSBF) program.
Secondly, they will utilize state of the art technology, called BioTrack, to accelerate taxonomic identification of the tens-of-thousands of individuals they expect to find. BioTrack, directed by GLIDE Co-Chair Dr. Mark Dangerfield at Maquarie University Australia, scans each specimen and creates a high resolution image. Computer software then compares the image with a ‘virtual collection’ to provide a match and identify the specimen.
Thirdly, all of the scientists participating in the project are volunteering their time to place the litterbags in the field and collect them.
The researchers expect that within a year GLIDE will yield unprecedented data on the animals involved in various stages of litter decomposition across different biomes and latitudes. This information will help answer important questions such as how significant the high diversity of litter fauna is for the functioning of ecosystems and how it is influenced by the environment.
More Information on the IBOY Project Global Litter Invertebrate Decomposition Experiment (GLIDE) see http://www.nrel.colostate.edu/projects/glide/ and http://www.nrel.colostate.edu/IBOY/goods_services.html#bignell.
More Information on BioTrack see http://biotrack.mq.edu.au/index.htm
Contact: Dr. Diana Wall, Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523-1499, USA. Tel; 1-970-491-2504; Fax: 1-970-491-3945; email: Diana@nrel.colostate.edu