Landscape Influences on Microclimate and Forest Growth Cessation in a Semiarid Montane Forest

Author

Fin A. Malone, University of Montana, Missoula

Graduation Year

2023

Graduation Month

May

Document Type

Thesis

Degree Name

Bachelor of Science

School or Department

Forestry and Conservation

Major

Wildland Restoration – Terrestrial

Faculty Mentor Department

Forestry and Conservation, College of

Faculty Mentor

Kelsey Jencso

Faculty Reader(s)

Ben Colman; Cara Nelson

Keywords

pseudotsuga menziesii, growth, microclimate, landscape, soil, SPAC

Subject Categories

Forest Biology | Hydrology

Abstract

As climate change impacts the severity and frequency of drought, knowledge of hillslope-to-watershed scale ecohydrology is becoming increasingly necessary to inform appropriate conservation, restoration, and management of forested ecosystems. In mountain environments, spatial patterns of water and energy organize forest productivity at plot, hillslope, and watershed scales. These hydrometeorological patterns are impacted by gradients in elevation, aspect, and local topographic convergence and divergence. In water-limited systems, such patterns of moisture may be first-order drivers of intra-annual tree growth. However, there is limited field-based research characterizing how seasonal limitations of forest growth may vary across complex terrain. In 2016, continuous soil moisture, vapor pressure deficit, temperature and radial Douglas-fir (Psuedotsuga menziesii) growth were collected across 27 sites within the Lubrecht Experimental Forest, MT. Using this data, we assessed the influences of topographic position, elevation, and aspect on local temperature and moisture conditions. These landscape and microclimatic predictors were then compared to the timing of tree growth cessation. Sites in convergent topographic positions, high elevations, and north-facing aspects were correlated with decreased temperature and greater moisture, which generally lead to later growth cessation. However, we also observed a nonlinear phenomenon where saturated soils contributed to early cessation at convergent topographic positions. Overall, average microclimatic measures predicted the complex timing of growth cessation across the watershed. These findings contribute to critical knowledge of landscape scale vegetation responses to changes in water availability, important for predicting the ramifications of climate change on forest growth.

Honors College Research Project

Yes

GLI Capstone Project

no

Recommended Citation

Malone, Fin A., "Landscape Influences on Microclimate and Forest Growth Cessation in a Semiarid Montane Forest" (2023). Undergraduate Theses, Professional Papers, and Capstone Artifacts. 438.
https://scholarworks.umt.edu/utpp/438