Date of Award:

5-2016

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Watershed Sciences

Committee Chair(s)

Karin M. Kettenring

Committee

Karin M. Kettenring

Committee

Karen E. Mock

Committee

Thomas A. Jones

Abstract

A primary goal of ecological restoration is to establish desirable plant species. This goal is particularly important following the removal of invasive plants. Understanding biological characteristics of plant species important to revegetation is crucial to plant establishment. In the globally important Great Salt Lake (GSL) wetlands, native habitat-forming bulrushes Bolboschoenus maritimus, Schoenoplectus acutus, and S. americanus are frequently displaced by the invasive grass Phragmites australis. Bulrush seeds require very specific germination conditions and are also dormant, therefore they do not germinate consistently even when exposed to appropriate germination conditions. Additionally, wetland environments are often associated with water level fluctuations, high salinities, and nutrient loading, which may affect bulrush establishment from planted material such as rhizomes. Successful revegetation of bulrushes relies on improving our understanding of seed dormancy break, seed germination requirements, and the environmental factors affecting rhizome emergence and growth. We used a series of germination chamber and greenhouse experiments to examine effective seed dormancy break treatments and germination conditions for multiple collection sites of bulrushes B. maritimus, S. acutus, and S. americanus. We also performed a greenhouse experiment to investigate how water depth, nutrient, and salinity levels affect B. maritimus and S. acutus emergence and growth from rhizomes. Cold, moist storage and bleach treatments were effective dormancy break treatments for all species, though the effect varied by species and site. Soaking the seeds in water after application of dormancy break treatments improved germination for all species. Rhizome emergence of S. acutus was negatively affected by high water depth, likely due to oxygen limitation. Bolboschoenus maritimus was salinity tolerant relative to S. acutus. GSL wetland managers can use these findings to improve revegetation projects via seeding and planting.

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