Graduation Year

2023

Graduation Month

May

Document Type

Thesis

Degree Name

Bachelor of Science

School or Department

Systems Ecology

Major

Environmental Science and Sustainability

Faculty Mentor Department

Systems Ecology

Faculty Mentor

Ben Colman

Keywords

willows, BDA, restoration, recruitment, SACS

Subject Categories

Terrestrial and Aquatic Ecology

Abstract

Willow establishment is a necessary objective of stream restoration due to their role in bank stabilization, stream shading, and enhancement of biodiversity across the riparian zone. However, anecdotal observation indicated that establishment on beaver dam analogue (BDA) restored streams may be lacking. BDA’s mimic the pooling effects of natural beaver structures and are intended to help recreate historic conditions that existed before beaver extirpation. When working as intended, ecosystem function is restored, and a major aspect of this is willow presence. Because of these observations, as well as limited information on willow recruitment following restoration, we ask the following questions. First, after BDA restoration, what is the abundance of willows in these restored sites? And, what is the abundance of willow recruits? Finally, to what extent do the environmental factors of water access, soil compaction, and abundance of competitor species impact the recruitment of willow? To answer this, we measured the density of willow and collected environmental data across 6 sites. We found willow density to be lower than expected with densities ranging from 1.6 stems/m2 to less than 0.1 stems/m2. Root sprout presence was limited, aside from two study sites that had additional restoration treatments. Although the two sites with root sprouts cannot paint a full picture of the correlation between our measurements and recruitment density, it is clear that willow regeneration is limited, if not nonexistent, without further interference. These findings contribute insight into the factors influencing willow recruitment and highlight a need to develop practices to improve willow establishment after restoration.

Honors College Research Project

No

GLI Capstone Project

no

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