Christopher A. Monz, David N. Cole, Lisa A. Johnson, and David R. Spildie

Abstract
The response of five native vegetation types to two years of applied trampling was investigated. Sites were located between an elevation of 2800 and 3200m in the Wind River Range in central Wyoming, USA. Plant communities included both woody and herbaceous forest understories, a subalpine meadow dominated by graminoids, an alpine grass community and an alpine fellfield. Experimental plots (0.5m x 1.5m) were subjected to trampling mid growing season at the rate of 25, 75, 200 and 500 passes, with the exception of the alpine fellfield and the alpine grass community that, instead of 25 passes, received 800 and 1000 passes respectively. Alpine communities exhibited the least decrease in plant cover while both forest understory communities showed significant decreases with as little as 25 passes. Intense trampling (500 passes) resulted in nearly 100% vegetation loss in some forest understory plots. Soil penetration resistance increased significantly with 200 passes in both forest understory sites, but did not respond to trampling at the other sites. Species richness tended to decrease in all plots with increasing trampling intensity. Canonical discriminant analysis revealed significant changes in plant community structure in all vegetation types, with low levels of trampling (75-200 passes) affecting forest understory communities and higher levels affecting the subalpine meadow and alpine communities.

Citation
Monz, C.A., D.N. Cole, L.A. Johnson and D.R. Spildie. 1994. Vegetation response to trampling in five native plant communities in the Wind River Range, Wyoming, USA. Bull. Ecological Society of America 75 (2): 158.