Year of Award

2024

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Resource Conservation

Department or School/College

W.A. Franke College of Forestry and Conservation

Committee Chair

Akasha Faist

Commitee Members

Anna Sala, Daniel Winkler

Keywords

Dryland restoration, native plant materials, perennial grass, germination, legacy effect

Subject Categories

Natural Resources and Conservation

Abstract

Globally, many drylands are in need of restoration due to anthropogenic land use changes, climate change-related biodiversity loss, and broad scale degradation. Within this degradation framework, many perennial grass species and populations have been lost from drylands. A common method of restoring vital perennial grass populations is through seed-based restoration. Using seed-based restoration, or the act of adding desirable seed to a system to restore plant populations, requires a depth of knowledge on species level responses, as well as seed sources within those species. My research examines three workhorse perennial grass species and associated seed sources for dryland restoration, especially in the face of changing climates. This work focuses on three species (Sporobolus cryptandrus, Bouteloua curtipendula, and Bouteloua gracilis) and three seed sources (Wild-collected, Cultivars, and Novel-composites). While Wild-collected and Cultivars have been previously used in seed-based restoration, Novel-composites are a recently emerging seed source that are developed by mixing seed from several wild populations, planting this mix, and then collecting the seed from this first generation. In the first chapter, I evaluate the germination characteristics of these species and seed sources in different environmental conditions. In the second chapter, I evaluate the evidence of a legacy effect due to emergence conditions within B. gracilis by associated seed source and environmental conditions. I found that the studied species and seed sources differ in their germination characteristics, such as germination proportion, time-to-germination, and seedling biomass, while warmer and wetter environmental conditions generally resulted in larger biomass and faster time-to-germination. I found that Cultivars generally germinated in greater proportions, had faster time-to-germination, and larger seedling biomass compared to the Wild-collected and Novel-composite seed sources. I did not find evidence of a legacy effect due to emergence conditions influencing biomass or leaf count in B. gracilis, but rather generally greater biomass in drier grow-out conditions. Overall, Cultivars generally out-performed Wild-collected and Novel-composite seeds in terms of greater germination proportion, faster time-to-germination, and biomass, as well as overall biomass at 3-months. With drylands inherently difficult to restore, my work showed species-specific and source-specific differences in germination that will aid in land managers plans.

Available for download on Wednesday, July 15, 2026

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