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Date of Award

Spring 2024

Document Type

Masters Thesis

Department or Program Affiliation

College of the Environment

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Bauman, Jenise

Second Advisor

Flower, Aquila

Third Advisor

Lawrence, Amy Paulson


Rapid climate change alters the conditions for which tree species can migrate successfully. Restoration efforts are vital for our future forests to ensure healthy and sustainable forests. Assisted migration is a restoration practice that can speed up trees' slow migration process, promoting resilient forests. This study assessed how genotypes from California, Oregon, and Washington nursery stock plants would succeed in a Western Washington-assisted population migration project. Additionally, we want to evaluate how transfer to new soil microbiomes will affect ectomycorrhizal (ECM), a fungus that forms symbiotic relationships with certain plant root tips. To achieve this, in January 2022, 900 plants (75 per species or 25 per genotype) of Douglas-fir (P. menziesii ssp.menziesii), Shore pine (Pinus contorta var. contorta), and Garry oak (Quercus garryana) were divided into four 0.2 hectare plots, three with irrigation and one without irrigation. ECM presence was assessed via root tip collection before planting. Upon planting, height and basal diameter were taken. In May 2023, height, basal diameter, and survival were recorded. In November 2022, ECM presence was assessed by collecting root tips from 10 trees per genotype, followed by DNA sequencing of the fungal internal transcribed spacer (ITS) region. The results of this study provide baseline data for a project that will be followed over the next decade. Initial findings suggest that some tree genotypes performed better than others. This study also confirmed that most ECM could maintain functional mycorrhizas in Washington restoration soils for an assisted population migration project when migrated from California and Oregon.




Assisted migration, Assisted population migration, climate change, ectomycorrhiza, ECM, Douglas-fir (P. menziesii ssp.menziesii), Shore pine (Pinus contorta var. contorta), Garry oak (Quercus garryana)


Western Washington University

OCLC Number


Subject – LCSH

Assisted migration (Plant colonization)--United States; Climatic changes--United States; Ectomycorrhizas; Douglas fir; Lodgepole pine; Oregon oak; Trees--United States; Forests and forestry--United States

Geographic Coverage

United States; Washington (State); Oregon; California




masters theses




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