The soil contamination legacy of postindustrial sites has become an issue of increasing ecological and public health concern. This study examines the ectomycorrhizal and above-ground plant relationships in the metaliferous soil of an urban brownfield. Ectomycorrhizal fungi (EMF) were microscopically identified by physical morphotyping followed by sequencing of ribosomal DNA. Plant productivity was assessed through Leaf Area Index (LAI) measurements taken from May through July 2012 and 2013. Results indicate that there were significant changes in EMF community composition and plant productivity based on their position along a total soil metal load gradient. Cenococcum geophilum was the dominant species in the soils where total soil metal load was below previously established threshold values, and Russula species were the dominant genera in soils where the total soil metal load was above the threshold value. Higher LAI values are seen in environments with higher soil metal levels. However, higher LAI could be due to multiple factors such as increased moisture and the dominance of metal-tolerant tree species. This study suggests that soil metal contamination affects plant productivity and EMF community composition and supports the idea that EMF species have varying levels of tolerance for metals.