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Date Permissions Signed


Date of Award

Summer 2018

Document Type

Masters Thesis

Degree Name

Master of Arts (MA)


Environmental Studies

First Advisor

Flower, Aquila

Second Advisor

Bach, Andrew J.

Third Advisor

Helfield, James M.


Seaside juniper (Juniperus maritima) is a recently discovered tree species endemic to the Salish Sea region and is an as yet unutilized dendrochronological resource. This study reports the first dendrochronological investigation of the species. We sought to determine if Seaside junipers are capable of crossdating, a requirement for consideration as a dendrochronology study species, and to identify correlations between instrumental climate records and radial growth to determine climate-growth response. We collected tree core samples from Seaside juniper in five sites throughout the San Juan Islands and nearby mainland. Samples collected from one of five sites successfully crossdated. Bootstrapped correlation function analysis found the dominant growth-limiting factor of Seaside junipers is growing season minimum temperatures in the prior year (r = 0.547) and in the current year (r = 0.524), potentially indicating a common growth-limiting factor of either temperature or solar irradiance. Understanding this climate-growth relationship will aid in development of a conservation strategy for this rare and endemic species.




dendrochronology, juniper, salish sea, ecology, washington state, wa, seaside juniper, maritima, dendroecology, san juan islands, gulf islands



Western Washington University

OCLC Number


Subject – LCSH

Junipers--Salish Sea Region (B.C. and Wash.); Junipers--Climatic factors--Salish Sea Region (B.C. and Wash.); Dendrochronology; Tree-rings

Geographic Coverage

Salish Sea Region (B.C. and Wash.)




masters theses




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Creative Commons License

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