Belowground Wood Stake Decomposition from Research Sites Across the Northeastern United States: First Year Results.

In 2012 and 2013, researchers from a variety of institutions initiated a study to evaluate belowground decomposition with the goal of improving our understanding of belowground carbon cycling, in order to advance belowground components of global carbon models. Wood stakes of 2 species (Pinus taeda L. and Populus tremuloides), carefully prepared to assure uniformity, were installed in the mineral soil and on the surface of the soil at 8 sites, utilizing on-going studies. These 2 species of wood serve as an index species, which can be compared among NRS sites, and with other study sites across the world. Five of the sites are Long Term Soil Productivity sites in Michigan, Minnesota, Missouri, and West Virginia. We have also established sites on the Baltimore Ecosystem Study (BES) (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. Finally, these locations were chosen because each hosts an ongoing experiment and the site characteristics have been sufficiently well-quantified, such that extensive site characterization sampling is not required. On 2 sites, additional local wood species (Acer saccharum in WV, and Acer rubrum in Somerset, MD) were added to the study in order to investigated belowground dynamics of local species. In all, almost 8500 wood stakes were placed in these 8 sites. Wood stakes were extracted from the mineral soil and surface after a year in the soil, and every year thereafter for 5 years. Decomposition is measured as mass loss, and change in penetrometer resistance. Termites were recorded in some sites, but not all of them. The relationships of decomposition with climatic and soil variables are presented.