First Advisor

Mike Ghedotti


Regis College

Degree Name

MS Environmental Biology

Document Type

Thesis - Open Access

Number of Pages

66 pages


Recreational trails and the presence of invasive species such as Bromus inermis can both disturb grassland community composition. Trails can act as dispersal corridors for plant material, but can also be a source of trampling and compaction. Invasive grasses like Bromus inermis can easily establish in grasslands and decrease species richness by increasing competition. Understanding these effects, this study aims to understand how both the presence of recreational trails as well as the presence of Bromus inermis affect species richness and overall community composition at Two Ponds National Wildlife Refuge. Belt transect sampling took place in fall 2019 and again in 2021. I used generalized linear modelling and mixed effect modelling to understand how distance from trails affected species richness and percent cover of Bromus inermis. I used non-metric multidimensional scaling (NMDS) to assess overall species community composition. I found that species richness was negatively impacted by distance from trail while percent cover of Bromus inermis was positively impacted. Additionally, species composition varied according to distance from trail, with differing effects for individual species. This study concludes that walking trails may act as a dispersal corridor for species as indicated by higher species richness while trails may hinder the growth of Bromus inermis due to trampling and soil compaction. Furthermore, the variation in community composition may result from individual species being able to disperse and propagate more easily along the trails. My findings contribute to ongoing research into management and ecology of urban grasslands in the face of several anthropogenic disturbances.

Date of Award

Spring 2024

Location (Creation)

Denver, Colo.

Rights Statement

All content in this Collection is owned by and subject to the exclusive control of Regis University and the authors of the materials. It is available only for research purposes and may not be used in violation of copyright laws or for unlawful purposes. The materials may not be downloaded in whole or in part without permission of the copyright holder or as otherwise authorized in the “fair use” standards of the U.S. copyright laws and regulations.