COS 20-8
Demystifying the enigma of soil biodiversity: long-term effects of 14 tree species and underlying mechanisms

Tuesday, August 6, 2013: 10:30 AM
101J, Minneapolis Convention Center
Kevin E. Mueller, Biological, Geological, and Environmental Sciences, Cleveland State University, Clevland, OH
Nico Eisenhauer, Institute of Ecology, Friedrich-Schiller-University Jena, Jena, Germany
Peter B. Reich, Department of Forest Resources, University of Minnesota, St. Paul, MN
Tomasz Dobies, Faculty of Forestry, Poznań University of Life Sciences
Cynthia Hale, The Natural Resources Research Institute, Center for Water and the Environment, University of Minnesota Duluth, Duluth, MN
Sarah E. Hobbie, Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN
Andrzej M. Jagodzinksi, Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
Izabela Kalucka, Department of Algology and Mycology, University of Łódź, Łódź, Poland
Marek Kasprowicz, Department of Plant Ecology and Environmental Protection, 9Adam Mickiewicz University, Poznań, Poland
Lukasz Sobczyk, Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
Małgorzata Stasińska, Department of Botany and Nature Protection, University of Szczecin, Szczecin, Poland
Lidia K. Trocha, Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
January Weiner, Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
Jacek Oleksyn, Polish Academy of Sciences, Institute of Dendrology, Poland

The enormous diversity of soil biota is a great riddle in ecology. We assessed the controls on soil biodiversity, including 13 different groups of soil organisms ranging from bacteria to macrofauna, using ~125 abiotic and biotic variables measured in replicated plantations of 14 tree species.  The plantations were planted in 1970 and 1971 after clear-cutting an even-aged stand of Pinus sylvestris.  The planted species included deciduous angiosperms, evergreen gymnosperms, and one deciduous gymnosperm.


Approximately 70% of the variability in total diversity of these soil organisms was explained by six variables. Soil biodiversity was increased by factors related to habitat and resource availability (fine root production, forest floor depth, and soil phosphorus content) as well as by factors indicating both fine-scale habitat heterogeneity and resource availability (understory light availability and biomass of earthworms). Strong positive effects of light availability on soil biodiversity could be explained in part by changes in soil temperature and herbaceous plant diversity. The 13 groups of soil organisms had highest diversity levels under eleven different tree species, stressing the relevance of tree diversity. These results suggest that a small number of key ecosystem factors strongly regulate soil biodiversity at the local scale.