Impact of Storm Water Runoff on tree Roots, Physiology and Rhizosphere Microbial Diversity in Urban Forests.

Urban forests are a critical component of modern infrastructure for maintaining natural environment, providing recreational areas, and reducing pollution. Social and medical benefits provided by urban forests in reducing stress of city life and renewing vital energy have been well documented. However urban forestry is challenged by poor soil quality, deficiency of nutrients, and widespread pollution from anthropogenic sources. Storm water runoff into urban forests carries large amounts of pollutants that include heavy metals, oils, pesticides, and poly aromatic hydrocarbons (PAHs). We collected water and soil from a urban forest which is periodically inundated by the adjoining creek and tested them for the impact of storm water pollutants. We also conducted a greenhouse experiment to evaluate the impact of storm water pollutants and measured root and shoot properties, photosynthetic efficiency, and microbial communities in the rhizosphere. We also measured pollutants in soil, plant roots and shoots. The results from this study indicate that pollutants influenced plant physiological functions as well as microbial communities in the rhizopsphere. The results from this study will be valuable in determining the source and extent of pollution because of storm water runoff. The knowledge gained from this study can be utilized to develop proper management strategies for storm water runoff in the urban ecosystem.