Document Type

Thesis - Open Access

Award Date

2019

Degree Name

Master of Science (MS)

Department

Natural Resource Management

First Advisor

Lan Xu

Abstract

The Northern Great Plains (NGP) mixed-grass prairie developed under fire, grazing, and periodic droughts, which created a heterogeneous landscape. Since European settlement, heterogeneous landscapes have declined due to fire suppression and the maximization of livestock production, leading to the need for an alternative management practice. Our overall project objective was to determine if heavy winter grazing could be used as an alternative to patch-burn grazing for promoting heterogeneity and improving ecosystem services in the NGP. Fire has been used very effectively in patch-burn grazing management to create heterogeneity in pastures in some areas, however burning is not readily adopted in many regions such as the NGP. The objectives of this particular part of the project were to evaluate the effects of conventional continuous season-long summer grazing, heavy winter grazing, and wildfire on the 1) aboveground vegetation structural and compositional heterogeneity, 2) soil seed bank heterogeneity, and 3) clonal traits of Bouteloua dactyloides for two years post-treatments. Research was conducted at the South Dakota State University Cottonwood Range and Livestock Field Station. The experiment was a randomized block design with three treatments occurring in each of three pastures (blocks). Five exclosures were constructed within each treatment within each pasture (15 exclosures/pasture); three 0.25-m2 permanent plots were randomly established in each exclosure. In each plot, total vegetation cover, cover by species, percent bare ground, and litter cover were estimated and vegetation height, and litter depth were separately measured in June and July for both years. Biomass was estimated in July. Soil cores were collected within each exclosure in October of both years to evaluate the emergent seed bank. Bouteloua dactyloides soil cores were collected three times during the summer of the second year post-treatments. Results indicate that heavy winter grazing and wildfire provided structural heterogeneity, while only the wildfire reduced compositional heterogeneity aboveground and in the soil seed bank. Clonal traits of Bouteloua dactyloides, including crown and stolon tiller and bud production, were unaffected by treatments after the second year post-treatment. This thesis contributes to the literature, pertaining to alternative management practices for improving structural and compositional heterogeneity in the NGP mixed-grass prairie. The author recommends future research expanding on heavy winter grazing and methods described in this thesis.

Format

application/pdf

Number of Pages

193

Publisher

South Dakota State University

Rights

In Copyright - Educational Use Permitted
http://rightsstatements.org/vocab/InC-EDU/1.0/

Share

COinS