Document Type

Thesis - Open Access

Award Date

2023

Degree Name

Master of Science (MS)

Department / School

Natural Resource Management

First Advisor

Lora Perkins

Second Advisor

A. Joshua Leffler

Abstract

Failures in seed-based restoration can be partially attributed to a lack of knowledge on seed dormancy. Dormancy is beneficial for plant establishment in unpredictable environmental conditions, but a lack of uniform germination can hinder restoration efforts. The purpose of this research was to gain a better understanding of dormancy displayed by select forbs of the northern Great Plains. The first data chapter attempted to identify and break dormancy class. Seeds were treated with scarification, smoke, and fertilizer pretreatments in an attempt to break seed dormancy. Seeds were also placed in spring and summer temperatures to identify how seasonal phenology influenced final germination and germination rate. The second data chapter attempted to identify how dormancy percentage varies between different seed sources of the same species. This chapter also investigates how short-term storage temperature and seed cleaning methods may influence physical dormancy levels. From the first data chapter, I determined that Erysimum asperum, Gaillardia aristata, and Ipomopsis aggregata all display physiological dormancy. Although the remaining species were nondormant, temperature did influence germination. From the second data chapter, I determined that levels of dormancy can vary drastically between different sources for the same species. Although I could not conclude why dormancy varied, I determined that short-term storage temperature and cleaning methods likely did not influence dormancy levels. From a management perspective, Dalea villosa seeds can be stored at room temperature or refrigerated, and can be dehulled with a hand debearder without concern of impacting dormancy levels. Temperatures and pretreatments found to be influential can be used to effect final germination and germination rate of these native species prior to seeding in restoration. Breaking dormancy of E. asperum, G. aristata, and I. aggregata before seeding will increase final germination of these species in the field, and increase restoration success in the northern Great Plains.

Library of Congress Subject Headings

Restoration ecology -- Great Plains.
Grasslands -- Great Plains.
Seeds -- Dormancy.
Dormancy in plants.
Germination.

Publisher

South Dakota State University

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Rights Statement

In Copyright