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Pollination Dynamics In Two Subalpine Flower Meadows, Peter Andrew Beedlow Iii

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant-pollinator interactions were studied in two subalpine meadows to determine the role of pollination in structuring the herbaceous flower communities. The majority of the entomophilous plant species set significantly less seed when caged to prevent visitation than when exposed to flower visitors. Visitation rate was directly related to temperature and radiation. The number of animal species visiting flowers each week was directly related to the number of plant species in bloom. Most visitor species used ≤3 species of plants, while most plant species hosted ≤8 species of flower visitors. Floral niche breadth increased with increasing animal species diversity, but animal …

Changes In Spider Community Attributes Along A Subalpine Successional Gradient, Gerald Norman Waagen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The spider communities of four stages of a successional sere leading to and including spruce forests were studied in northern Utah. Four seral stages were recognized. These include: meadows, aspen (Populus tremuloides) stands, subalpine fir (Abies lasiocarpa) forest, and the climax Engelmann spruce (Pica engelmanii) forests.

During the snow-free periods of 1976, 1977 and 1978, 15,987 spiders were collected by three methods including: pitfall traps, by beating vegetation, and with sweep-net samples. Additionally, 1600 15-second intervals of behavioral observations, and measurements of 182 web locations were made.

Of 99 species collected, 44 were considered …