Impacts of Cattle Grazing as a Tool to Control <i>Phragmites australis</i> in Wetlands on Nitrogen, Phosphorus, and Carbon

Phragmites australis is a plant that is causing problems in wetlands by outcompeting native plants that provide food and shelter for millions of migratory birds. Currently, managers try to control Phragmites australis by spraying herbicide, burning, and mowing, but these methods are costly, time con...

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Bibliographic Details
Main Author: Duncan, Brittany L.
Format: Others
Published: DigitalCommons@USU 2019
Subjects:
Online Access:https://digitalcommons.usu.edu/etd/7420
https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=8539&amp;context=etd
Description
Summary:Phragmites australis is a plant that is causing problems in wetlands by outcompeting native plants that provide food and shelter for millions of migratory birds. Currently, managers try to control Phragmites australis by spraying herbicide, burning, and mowing, but these methods are costly, time consuming, and have low levels of success. Adding grazing as a tool to control Phragmites australis provides a cheap and low labor alternative. However, there are many concerns regarding if grazing will cause nutrient loading in our wetlands that will decrease water quality and alter beneficial functions of wetlands. To better understand the effects of grazing in wetlands, we proposed a two-year study and received funding from many organizations including the Utah Department of Fire, Forestry, and State Lands, South Davis Sewer District, and the Utah Department of Environmental Quality and Water Quality. Also, the Utah Department of Natural Resources helped tremendously in allowing access to the sites, in the actual implementation of the project, coordinating with local ranchers who allowed for their cattle to be in the study, managed their cattle during the study, and assisted with fence installation, and many volunteers from Utah dedicated hunters helped with the fence installation. We collected water, manure, soil, and leaf samples over time to analyze nutrient changes and measured changes in the plants, water levels, soil cover, and litter cover over time. We then compiled and analyzed this information to better understand how grazing impacts our wetlands. As a result, we were able to make some recommendations for future research and how best to graze in wetlands with minimal impacts according to the information we found.