Belowground Wood Stake Decomposition in Forest Soils in the Northeast and Midwest.

In 2012 and 2013, we began a cross-site study to evaluate belowground decomposition of wood in a variety of forest soils. Wood stakes of 2 species (Pinus taeda L. and Populus tremuloides) were installed in the mineral soil and on the surface of the soil at 8 sites across the Northeast and Midwest, utilizing on-going studies. These 2 species of wood serve as index species, which can be compared among sites, and with other study sites across the world. Five of the sites are Long Term Soil Productivity (LTSP) sites in Michigan, Minnesota, Missouri, and West Virginia. We have also established sites on the Baltimore Ecosystem Study (urban forested, and a non-urban (rural) forest), on a series of hydrologically restored forested wetlands near Somerset, MD, and in an afforestation experiment in Kissena Corridor Park in Queens, NY. These sites were selected because they cumulatively represent a broad gradient of soil type, temperature, and moisture. Also, they represent a variety of forest types, including sites undergoing restoration activities. On 2 sites, local wood species (Acer saccharum in WV, and Acer rubrum in Somerset, MD) were added to the study in order to investigate belowground dynamics of local species. In total, almost 8500 wood stakes were placed in these 8 sites. The microbial communities of the soil were characterized at the time wood stakes were installed. Wood stakes have been extracted from the mineral soil and surface annually. Decomposition varied among the sites, and the community composition of the microbiota also varied. In this presentation we explore the results after 3 years, and the relationships between decomposition, climatic variables and microbial communities.