Graduation Date
Spring 2026
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Forestry, Watershed, & Wildland Sciences
Committee Chair Name
Lucy Kerhoulas
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Rosemary Sherriff
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Erik Jules
Keywords
Glacier, Succession, Climate change, Refugium, Trinity Alps, Klamath Mountains
Subject Categories
Botany
Abstract
The recent extinction of the Salmon Glacier in the Trinity Alps, California, provides a rare opportunity to examine post-glacial succession in a region of high endemism experiencing climatic stress. Using a chronosequence spanning ~150 years since deglaciation, I investigated (1) vegetation successional trajectories in the foreland, (2) whether the foreland functions as a climate refugium for alpine specialists, and (3) whether facilitative interactions between the dominant vascular plant (DVP) and bryophytes occur and persist through succession. I surveyed 100 plots across 11 transects within the foreland and 40 randomized plots in adjacent ecosystems. Successional patterns and refugial potential were analyzed using Bayesian hierarchical models and multivariate approaches, and spatial interactions were assessed along two transects.
Species richness, growth-form diversity, and compositional turnover relative to the oldest communities increased with distance from the 2014 glacier margin (> 95% posterior probability). The proportion of alpine species declined with community age (> 95% posterior probability), suggesting that the foreland acts as a modest, ephemeral refugium. Plant community composition differed significantly among alpine, moraine, and foreland habitats (p < 0.0001), with the foreland supporting a distinct assemblage. Several rare alpine endemics remained absent after ~150 years of potential establishment. Spatial associations between bryophytes and the DVP indicated potential facilitation, though no consistent successional trend was detected. Overall, the Salmon Glacier foreland follows typical post-glacial successional patterns and appears to function as a transient rather than persistent refugium for alpine specialists under ongoing environmental change.
Citation Style
CSE (Northwest Scientific)
Recommended Citation
Evans, Sebastian, "Succession and alpine plant habitat of a recently deglaciated foreland in the Trinity Alps, California" (2026). Cal Poly Humboldt theses and projects. 2575.
https://digitalcommons.humboldt.edu/etd/2575
Included in
Biodiversity Commons, Botany Commons, Other Plant Sciences Commons, Plant Biology Commons