Presentation Type
Poster Presentation
Category
STEM (science, technology, engineering, mathematics)
Abstract/Artist Statement
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 microclimatic 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 growth were collected at 27 Douglas-fir (Psuedotsuga menziesii) sites within the Lubrecht Experimental Forest, MT. Using these data, we assessed the influences of topographic position, elevation, and aspect on hillslope-scale microclimates. These landscape and microclimatic predictors were then compared to the observed timing of tree growth cessation. Trees located in convergent topographic positions, high elevations, and north-facing aspects were correlated with decreased temperature and greater moisture, which generally led to later growth cessation. However, we also observed that perennially saturated soil conditions in some hillslope hollows resulted in earlier cessation. Overall, average microclimatic measures predicted the complex timing of growth cessation across the watershed better than static landscape proxies. 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.
Mentor Name
Kelsey Jencso
Landscape Influences on Microclimate and Tree Growth Cessation in a Semi-arid Montane Forest
UC North Ballroom
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 microclimatic 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 growth were collected at 27 Douglas-fir (Psuedotsuga menziesii) sites within the Lubrecht Experimental Forest, MT. Using these data, we assessed the influences of topographic position, elevation, and aspect on hillslope-scale microclimates. These landscape and microclimatic predictors were then compared to the observed timing of tree growth cessation. Trees located in convergent topographic positions, high elevations, and north-facing aspects were correlated with decreased temperature and greater moisture, which generally led to later growth cessation. However, we also observed that perennially saturated soil conditions in some hillslope hollows resulted in earlier cessation. Overall, average microclimatic measures predicted the complex timing of growth cessation across the watershed better than static landscape proxies. 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.