Merging Urban Soil Research Networks to Develop a More Comprehensive Understanding of Decomposition Rates Across Scales.

Urban soils provide ecosystem services such as decomposition which affects greenhouse gas fluxes, organic matter transformation rates, and nutrient cycling.  Leveraging insights from research networks may significantly improve our understanding of organic matter decomposition in ever-evolving urban soils.  Multi-city data are collected with standardized protocols, sample collection and lab resources are shared, and citizen scientists are involved.  Initial collaboration is focused on two emerging networks: 1) the Global Urban Soil Ecological Education Network (GLUSEEN) and 2) community of researchers focused on coarse woody debris decomposition.  This collaboration can provide worldwide multi-city comparisons improving our understanding of the effects of urban environments on decomposition and soil community structure.  Research topics include: 1) response of soil biodiversity and decay rates in urban soils at local, regional and global scales, 2) how differences in soil biodiversity among urban habitats relate to functional changes in the decomposer subsystem, and 3) the effects of abiotic soil properties on decomposition.  GLUSEEN uses pre-soaked teabags, where the mass loss of tea leaves is primarily caused by microbial activity, whereas coarse woody debris, i.e. wood stakes, follows the decay of wood, which is accessible by fungi and xylophagous macrofauna.  One of the working hypotheses in both studies is that in urban disturbed soils the decomposer food web shifts from fungal dominated to a bacterial dominated system. We will present results from field experiments already ongoing in several cities. This information will allow us to evaluate soil ecosystem services in urban environments.