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Below check out our active projects in the lab. We are thankful to IANRE, our partners, and our funding sources for the support to do this important work.

The main tools we use in our research include leaf and soil-level gas exchange, stable isotopes, plant and soil hydraulic properties, plant water stress, pigment concentration, automated measurements of tree water content/stress/flux and growth, UAVs (multispectral camera, Lidar), dendrochronology & xylem anatomy, Bayesian data modeling, and R for data processing.

tree canopy
Boreal forest
Boreal forest

Boreal Forest Carbon and Water Cycling: Response to Climate and Insect Infestation Using Field Measurements, Dendrochronology, & Remote sensing

Funded by: USDA NIFA McIntire Stennis Program, PI Dr. Jessie Young-Robertson & co-I Dr. Dave Valentine

This project explores the impact of intra- and inter-annual environmental variability on Interior Alaska’s boreal forest and the consequences for forest health, including the response to drought and shifts in the timing of snowmelt. Specifically, we are focusing on the response of forest carbon and water cycling processes to changes in daily, seasonal, and annual climate and soil conditions across the highly heterogeneous ecotypes that compose the boreal landscape, including permafrost and permafrost-free soils. We are exploring the consequences of increased deciduous vegetation cover for boreal ecosystem water and carbon cycling. This project also evaluates plant stress and water content across scales using field, UAV, and remote sensing with Dr. Simon Zwieback (Geophysical Institute, UAF). This work initiates a forward-looking research focus in scale-bridging forestry research that tightly integrates fieldwork with remote sensing. 

Click on the tabs to learn more about the project.


Data from this and our other studies will be used to parameterize a Bayesian-based plant ecophysiological model that integrates plant water and carbon cycling processes. The model will: (1) include the impact of environmental drivers on ecophysiological processes and contribute to a better understanding of the impact of beetle infestation on spruce function as the tree dies, forest stress indicators, and forest health. (2) Be used to analyze and integrate diverse datasets, with a framework that will allow for the prediction of ecophysiological responses, water balance, and growth in response to future environmental conditions. (3) Be calibrated and validated for significant boreal tree species (white spruce, black spruce, birch, and aspen), shrubs (alder), and agricultural species grown as part of variety trials at conducted at AFES.

boreal forest

Spruce Response to Beetle Infestation in Alaska: An Evaluation of Tree Ecophysiology Using an Integrated Field and Modeling Approach

Funded by: USDA NIFA Hatch Program, PI Dr. Jessie Young-Robertson & co-I Glenna Gannon and Dr. Jan Dawe

The overall goal of this project is to quantify the ecophysiological response of white spruce to bark beetle infestation in Alaska’s boreal forest, including the characteristics of the early “green attack” phase. To evaluate the ecophysiological response, this study also quantifies the roles of landscape characteristics, climate conditions, and stand composition in affecting the vulnerability of white spruce stands to attack. This project focuses on intensive field campaigns, UAV data collection, continuous measurements of tree stress/growth/water use/water content (as part of our 20-site network), and remote sensing (with Dr. Simon Zwieback). Data will be used to calibrate the aforementioned plant ecophysiological model.

We will share the results with the OneTree citizen science community through 2 seminars, a poster for the STEAM studio, a video produced for the UAF Extension Channel, and a short workshop for citizen scientists on collecting basic ecophysiological data and simple model parameterization activities. 

This project could not happen without our partnerships with Ahtna Native Corporation (Vernon Carlson) and Jason Moan (Alaska Division of Forestry). 

boreal forest
microscopic view of tree ring
microscopic view of tree ring

Quantifying Boreal Forest Tree Health, Growth, and Resilience in Response to Climate Change and Pathogens Using Plant Physiology-Informed Dendrochronology

Funded by: USDA NIFA Hatch Program, PI Dr. Jessie Young-Robertson & co-I Dr. Glenn Juday

To predict how the boreal forest will respond to climate change in the future, it is imperative to integrate our understanding of how forests responded to environmental stressors in the past with how forests are responding to current environmental stressors. This can be accomplished by integrating the reconstruction of past patterns inferred through tree rings (i.e., dendrochronology) with information about current relationships between plant physiology and environment. We refer to this integration of dendrochronology, xylem anatomy, and contemporary plant physiology as plant physiology-informed tree ring analyses.

The goal of this study is to examine the long-term climate dynamics and the impact on long-term Interior Alaskan boreal forest tree health, growth, resilience, and water use using an integrated research approach that combines sub-seasonal measurements of tree physiology, tree structure, and long-term records of dendrochronology. We will address this goal by: (a) by collecting tree cores near the long-term field sites that have been established by the lab for analysis of wood anatomy, isotope composition, and ring widths, (b) reanalyzing a large collection of tree cores for stable isotope composition and integrating these data with prior ring width analyses, and (c) continuing measurements of tree growth and health at Dr. Juday's long-term monitoring sites in the boreal forest.

wood stack

Firewood Harvesting Based on Tree Water Content

Funded by: USDA NIFA McIntire Stennis Program, PI - Dr. Young-Robertson, co-I - Dr. Joe Little

We are applying our data and knowledge about tree water content to inform people as to when they should harvest trees for firewood. Since the amount of water in trees varies over the year, the better times to harvest are those when the tree is naturally dry. This reduces the amount of time needed to dry the split and stacked wood before burning it to heat their homes. Click here to learn more.

boreal forest

Cooperative Alaska Forest Inventory

Funded by: USDA NIFA McIntire Stennis Program, with match provided by Alaska State Division of Forestry

This project is in partnership with Dr. Miho Welton at the Alaska State Division of Forestry. 

The Cooperative Alaska Forest Inventory (CAFI) was launched in 1994 and continued until 2015. The CAFI is the most extensive forest monitoring program, both in spatial and temporal scale, in Interior and southcentral Alaska today. The national Forest Inventory and Analysis (FIA) program began in the Interior and southcentral Alaska in 2016 that covers the entire boreal forest, but the second measurements will likely not occur for 10-20 years.

One of the essential pieces of information for decision making in forest management is growth and yield models, but reliable models do not exist for the Alaskan boreal forest. Climate of boreal Alaska is changing more rapidly than most other forest regions. Warmer and drier weather might have caused slower growth or mortality of trees in the region. The repeated long-term measurements done by CAFI enables us to develop growth and yield models under changing climate. The CAFI was a repeated forest measurement conducted by University of Alaska Fairbanks (UAF) between 1994 and 2015. During this time, 205 plots consisting of three 66’ × 66’ (0.1 acre) subplots were sampled. All plots are road accessible. Repeated measurements were done at a 5-year interval. Each plot was sampled up to five times during the 1994-2015 period. In an effort to reinitiate the program, State of Alaska Division of Forestry (AKDOF) remeasured five plots in 2020. Over the last 25 years, 63,831 trees have been sampled. The CAFI plots encompass a wide range of forest types and age classes, but age data are only available for 100 plots. ​ This project provides jobs for 3-4 people over the summer, including technicians who are new to forestry research.

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