Document Type

Thesis - Open Access

Award Date

1978

Degree Name

Master of Science (MS)

Department

Wildlife and Fisheries Science

Abstract

Effects of grazing systems on sharp-tailed grouse (Pedioecetes phasianellus jamesi) nesting and brooding habitats in the Little Missouri National Grasslands of southwestern North Dakota were evaluated. Three grazing allotments with deferred-rotation grazing systems and three allotments with season-long grazing systems were randomly selected for study. Fifty measurements of vegetation were taken using the height-density pole on line transects in each of three range sites; rolling grasslands, upland grasslands and lowland draws. Vegetation was sampled in late spring, summer and fall of 1976 and early spring of 1977. Average height-density of vegetation for the season-long grazing system was significantly greater than vegetation in the deferred-rotation system (P<0.01). Average visual obstruction readings (VOR) were 1.10 ± .02 for the season-long systems and 0.75±.02 for deferred-rotation systems. Grazing allotments utilizing the season-long grazing system had consistently higher VOR averages than allotments with the deferred-rotation system in all four sampling periods. Visual obstruction readings increased form late spring (1.15±.03) to summer (1.32±.03) and decreased in the fall (0.69±.03). The following early spring, VOR average decreased to 0.55±.03. Vegetation around six stock ponds each grazing system was measured on three line transects radiating from each pond. Fifty measurements of vegetation were taken in six 91.4 m segments during the summer and fall 1976. Visual obstruction readings of vegetation around ponds in season-long systems were significantly higher (P<0.05) than VOR of vegetation around ponds in deferred-rotation systems. Height and density of vegetation became uniform beyond 182.8 m from each pond edge. The use of the deferred-rotation grazing system may be detrimental to vegetation cover types used by sharptails for nesting and brooding. A re-evaluation of the range capacity ratings and land management techniques on the grasslands will benefit sharp-tailed grouse habitat in southwestern North Dakota.

Library of Congress Subject Headings

Sharp-tailed grouse
Grazing -- Environamental aspects -- North Dakota

Description

Includes bibliographical references (pages 31-33)

Format

application/pdf

Number of Pages

54

Publisher

South Dakota State University

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