Soil Microbial Community Effects on Quercus Rubra Seedling Survival at Harvard Forest 2016-2017

Feedbacks between plants and their soil microbial communities often drive negative density dependence in tropical forests, but their importance for tree demographics in temperate forests remains unclear. Additionally, the relative contribution of intraspecific seedling competition and soil pathogens to density-dependent patterns has rarely been assessed. We assessed how the soil microbial community influenced Quercus rubra seedling survival by growing seedlings in a greenhouse inoculated with soil collected from beneath conspecific and heterospecific mature trees. We found that seedlings grown with soil from beneath conspecific adults had a higher mortality rate than seedlings grown with soil from beneath heterospecific adults; therefore adult plant-soil feedbacks decrease seedling survival in Q. rubra.