ICOM1 Abstract

talk session 3 CRIPPS, CATHY L. Dept. of Plant Pathology, Montana State University, Bozeman, MT 59717. -Ectomycorrhizal communities with aspen on smelter-impacted sites: how ecosystems recover from airborne pollution Airborne pollution from copper smelters denuded vast acreages in western Montana in the early 1900's, and left a legacy of acidified soil laced with heavy metals. Aspen are colonizing these areas and provide an opportunity to examine the role of ectomycorrhizal fungi in the natural recovery of smelter-impacted sites. This study examined the species of ectomycorrhizal fungi which can survive in, and are important to, these stressed systems. The long range goal is to incorporate this information into reclamation strategies to accelerate successional processes with appropriate fungal inoculum for a specific set of conditions. Aspen stands in smelter-impacted areas near Butte and Anaconda hosted a subset of the ectomycorrhizal fungi which occur with aspen in Montana. Some stands were dominated by a few tolerant species such as Inocybe lacera, Paxillus vernalis, and Laccaria proxima. Other aspen- covered areas displayed a greater diversity of ectomycorrhizal fungi which are discussed. Over 14 species of Inocybe were associated with aspen on these stressed sites. Ectomycorrhizae were examined in one stressed aspen stand to determine if sporocarps are a reliable measure of the (inferred) importance of fungal species in stressed systems where fruiting may be limited. Only half of the fungal species in the aspen stand fruited in 4 years. Only one fruiting body of Paxillus vernalis appeared in 4 years, yet 25% of the ectomycorrhizae sampled were this type. In addition, a majority of the ectomycorrhizae occurred deep in the soil of the aspen stand, from 16 to 48 cm.