Natural Resources, School of

 

First Advisor

Larkin A. Powell

Second Advisor

Walter H. Schacht

Date of this Version

Spring 5-2017

Comments

A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Natural Resource Sciences (Applied Ecology), Under the Supervision of Professors Larkin A. Powell and Walter H. Schacht. Lincoln, Nebraska: May, 2017

Copyright (c) 2017 Maggi Sue Sliwinski

Abstract

Native rangelands in the Great Plains are largely privately owned and used for beef production. Vegetation heterogeneity is important for maintaining biodiversity, but private land may be more homogenous than desired. My research had two components: 1) to examine whether a variety of grazing strategies created vegetation heterogeneity in a large, intact rangeland, and 2) to understand beef producers’ attitudes about vegetation heterogeneity.

First, I sampled vegetation structure, composition, and bird abundance at multiple plots on eleven management units in Cherry County, Nebraska. Units were managed with commonly used grazing strategies (e.g., short-duration grazing and season-long continuous grazing). I examined the relationship of vegetation heterogeneity, bird abundance, and bird communities to grazing management variables using various analytical techniques. Grazing strategy had few relationships to vegetation structure or bird abundance and communities, but structure and birds were most often predicted by pasture-level grazing management variables, like stocking rate and season of use. Therefore, multiple grazing strategies on a landscape did not contribute to vegetation heterogeneity, and vegetation structure and bird communities were more homogenous than expected. The goal of ranchers to efficiently use their vegetation resource likely overwhelmed any effect of grazing strategy. Public land could be used to ensure that heterogeneity exists on the landscape for species that cannot find suitable habitat on private land.

Second, I interviewed 12 beef producers to explore their opinions of heterogeneity, and conducted a mail survey of producers in Nebraska, South Dakota, and North Dakota. Both indicated that beef producers’ main concern is sustainable beef production, and this likely contributes to homogenizing the rangeland landscape. My data confirm that producers appreciated wildlife and have positive views toward landscape management. Although fire and prairie dogs might enhance heterogeneity of vegetation, these were negatively viewed because they increased risk to the producer. Producers’ responses provided insights on how conservationists should engage them in biodiversity conservation. Importantly, “seeing is believing”. If conservationists can use existing resources, like university ranches, to show the benefits of managing for heterogeneity, they may be more likely to adopt those practices. I recommend engaging producers through Extension and field days.