Life Sciences Commons^™

Limitations On Canada Goose Production At Fish Springs National Wildlife Refuge, Utah, Dorie S. Stolley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Canada geese (Branta canadensis) recently have become management problems in some areas due to overpopulation. At Fish Springs National Wildlife Refuge (NWR), managers are concerned with the opposite situation. Despite attempts to boost production, only 18 to 34 goslings of the western Canada goose (B. c. moffitti) were produced per year, from 1989 to 1993. I studied the breeding population from March to July in 1996 and 1997. Results suggest that production is limited in 3 ways: low gosling survival, low nesting success for ground nests, and low number of breeding pairs.

Gosling survival to fledging …

Estimating Optimum Overstory Vegetation Reduction For Increasing Understory Production, John A. Tanaka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to investigate analytical approaches for estimating the optimum (profit maximizing) rate of initial overstory kill for increasing seasonal forage availability on a specific ranch. The models were developed using the big sagebrush (Artemisia tridentata) - crested wheatgrass (Agropyron cristatum, A. desertorum) vegetation type on a Utah cow-calf-yearling operation as an example. The models should be applicable on any ranching situation where understory forage production is constrained by the establishment and growth of undesirable overstory vegetation.

Three model forms were developed and compared for their applicability to on-the-ground investment decision …

Diversity And Production Of Herbaceous Vegetation In A Northern Utah Subalpine Chronosequence, Gary A. Reese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Successional trends in herbaceous plant production and diversity were studied in an age sequence of sites, i.e. chronosequence, inferred to represent a meadow to aspen to fir to spruce-fir sere. Primary production was observed to decrease in a linear fashion with successional development. Three components of diversity; richness, heterogeneity, and equitability or evenness, each had low early successional values, reaching maximum diversity in mid-succession, and declining to intermediate levels with maturity. The magnitude of these trends varied greatly, depending on the methods used to determine plant dominance. Characteristics of various dominance indices and their applicability to this study were examined. …