Relationships Between Va Mycorrhizal Fungi and Plant Cover Following Surface Mining in Wyoming

Abstract

Spoil spore counts of vesicular arbuscular mycorrhizal (VAM) fungi, VAM root infection, and percent cover of plants were assessed on reclaimed soil and spoil (1-6 years old), orphan spoil (10-31 years old), and undisturbed native sites. There was no relationship of site age with spore densities. Topsoiled sites almost always had significantly higher spore counts than spoil sites (reclaimed or orphan), indicating the importance of substrate on spore colonization and reproduction. Percent root infection of Agropyron smithii and A. dasystachyum showed no increasing trends with time in the mined sites (1-31 years), but the plants in the undisturbed site had greater infection than in any of the mined sites. There was also no correlation between percent cover of Agropyron and root infection or spore counts. These results suggest that time since disturbance is not an adequate explanation for the development of VAM infection and spore counts during the first 31 years, but that other factors such as the kind of substrate may be more important considerations.