Dissertations and Theses @ UNI

Availability

Open Access Thesis

Keywords

Prairie plants--Seeds--Predators of--Control--Middle West; Granivores--Control--Middle West;

Abstract

Restoration efforts in the tallgrass prairie ecosystem are inhibited by high seed cost and as little as 10% emergence of planted, pure live seed. This study examined the portion of loss due to seed predation and sought to reduce this predation in new roadside prairie plantings. Studies document the occurrence of predation in several plant communities and across all plant families, but little is known about how to reduce the impact of seed predators, especially in a restoration setting. On three sites where native prairie seed was recently drilled, we attempted to satiate seed predators by broadcasting a supplemental food source—birdseed at ten times the rate of the prairie seed. The goal of this method was to capitalize on the evolutionary principals of optimal diet theory and masting in order to protect seed from predation. We quantified seed predation through the use of a buffet experiment during the same fall as the planting, and by monitoring early seedling establishment the following summer. We predicted a reduced loss of prairie seed in the supplemental seed treatment of the buffet experiment. During the growing season, we expected to find increased seedling establishment in the supplemental seed treatment. Results of the buffet experiment show limited seed predation, with no significant effect of the supplemental seed treatment and temporal variation at each of the sites. As this data was collected after a frost, lack of invertebrate seed predators could have influenced the low rates of predation. Results from the growing season showed that the supplemental seed treatment increased early seedling establishment, yielding 37% more seedlings than in control plots. Detecting a treatment effect in the summer, but not in the fall may suggest that these plantings did not face high predation pressure this late in the fall, but that predators found the seeds sometime over the winter or in the spring. Further studies should test the most optimal time of year to apply the treatment and look at the effect of the treatment on sites with different disturbance characteristics. It is also important to use the treatment along with the recommended management guidelines for the site. Reducing predation on prairie seed through the use of supplemental seed could provide a practical, inexpensive strategy to improve prairie restorations across the Midwest.

Year of Submission

2016

Degree Name

Master of Science

Department

Department of Biology

Department

Tallgrass Prairie Center

First Advisor

Laura L. Jackson, Chair

Date Original

5-2016

Object Description

1 PDF file (vi, 61 pages)

Language

en

File Format

application/pdf

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