Arbuscular mycorrhizal fungi (AMF) form symbiotic connections with host-plant roots, providing nutrients, especially nitrogen (N) and phosphorous (P), in exchange for carbon, benefiting both members of the relationship. However, in phosphorous abundant soils, it is unclear whether host plants will benefit from AMF. It is also unclear whether competition-derived stress influences AMF colonization. Eastern redcedar (ERC; Juniperus virginiana), is a tree species that obligates AMF. We tested soil nutrient content (N and P) and intraspecific competition (no competitors vs. competition with four ERC’s), and harvested fine roots from three-year-old ERC’s from three field sites in Ohio. After staining AMF with trypan blue and quantifying colonization under a dissecting microscope, our results suggest that high interspecific competition and low nutrient availability correlate with stronger symbiotic reliance.