How Do Heatwaves Impact Pacific Northwest Forest Trees?
My PhD research aims to characterize species' vulnerability to extreme heat events such as the 2021 Western North America Heat Dome.
I am currently a PhD student at the University of British Columbia in the lab of Dr. Sean Michaletz where I seek to explore the physiological, anatomical, and morphological determinants of leaf thermoregulation and photosynthetic thermotolerance in maritime conifers of the Pacific Northwest. My interest was galvanized by the unprecended 2021 Pacific Northwest Heat Dome which exposed forests in the region to temperatures in excess of 15°C above historical averages - briefly converting this large terrestrial carbon sink to a net carbon source during one of the most extreme weather anomalies in recorded history.
Previously, I was a research associate at the University of Montana in the lab of Dr. Anna Sala where I managed a DOE-funded collaborative research project investigating the interactive impacts of drought, non-structural carbohydrate depletion, and common mycorrhizal network connectivity on water relations in ponderosa pine.
In addition to my PhD research, I contribute to ongoing investigations on fruit tree physiology and orchard management at Washington State University. There, I focus on developing near-infrared spectroscopy models for non-destructive fruit quality estimation, and attempt to disentangle the complex relationships between the fruit quality parameters we measure with instruments vs. the way consumers perceive flavor and make purchasing decisions. In addition, I help establish management recommendations for the new (and exceptionally tasty!) apple cultivar Cosmic Crisp®.
Current Projects
Mycorrhizal Networks and NSC Depletion Effects on Water Relations
Forest trees often form beneficial relationships with fungal networks by exchanging carbon for nutrients - but these associations may become unfavorable when carbon is limiting such as periods of drought when stomatal closure limits photosynthetic assimilation. By manipulating rainfall, light availability, and mycorrhizal network connectivity in the field, I am working to understand how non-structural carbohydrate (NSC) abundance interacts with mycorhizzal connectivity in influencing water relations, specifically turgor maintenance and hydraulic vulnerability to embolism in ponderosa pine forests of western Montana.
Improving Osmotic Potential Determinations in Conifers
Osmotic potential grants invaluable insight into water relations and turgor maintenance. However, several challenges exist in the precise and accurate determination of this key metric, including dilution of symplastic osmolality from the apoplast during tissue preparation - an issue compounded in conifers given the often-unavoidable sampling of leaf midveins and resin ducts. Additionally, rehydration techniques can introduce substantial errors in the determination of osmotic potential at full turgor - a metric that has been suggested as a suitable predictor of turgor loss point compared to time-intensive pressure-volume curves. By correlating osmotic potential determinations derived from traditional PV curves and direct observations via thermocouple osmometry, I will be able to estimate the degree of apoplastic dilution in conifer leaves as it varies among species and tissue preparation techniques, how the magnitude of this dilution effect scales with the degree of rehydration necessary to acheive full turgor, and if hysteresis during rehydration of tissues affects either osmotic potential or TLP estimation (preview - it does!).
Fruit Dry Matter & Consumer Acceptance
Ensuring a consistent eating experience across harvests, orchards, and even individual fruit is a challenge in the tree fruit industry given immense variability in growing and handling practices. Fruit dry matter is increasingly recognized as a reliable indicator of fruit quality. Using non-destructive near-infrared spectroscopy, I aim to develop models to assess fruit dry matter accurately and rapidly in both field and packhouse settings as a decision aid for growers and handlers. I also seek to establish correlations between fruit quality parameters (including dry matter) and consumer eating experiences in association with the Sensory Science Lab at Washington State University.
WA38/Cosmic Crisp® Apple
Cosmic Crisp® is the delicious result of a 1997 cross between cv. Honeycrisp and Enterprise apple developed at Washington State University. With over 12 million trees planted in 2019, it is the largest introduction of any horticultural commodity in history. I work to provide actionable management recommendations for growers to promote yield, fruit quality, and long-term orchard viability for this exciting new cultivar.
Publications
6. Goke, A., Martin, P.H. (2023). Drought-induced photosynthetic decline and recruitment losses are mediated by light microenvironment in Rocky Mountain subalpine forest tree seedlings. Forest Ecology and Management, 546.
5. McCulloh, K.A., Augustine, S.P., Goke, A., Jordan, R., Krieg, C.P., O'Keefe, K., & Smith, D.D. (2023). At least it's a dry cold: the global distribution of freeze-thaw and drought stress and the hydraulic traits that may impart tolerance in conifers. Tree Physiology, 43(1), 1-15.
4. Goke, A., Martin, P.H. (2022). Poor acclimation to experimental field drought in subalpine forest tree seedlings. AoB Plants, 14(1), plab077.
3. Goke, A., Serra, S., & Musacchi, S. (2020). Manipulation of fruit dry matter via seasonal pruning and its relationship to d’Anjou pear yield and fruit quality. Agronomy, 10(6), 897.
2. Serra, S., Goke, A., Diako, C., Vixie, B., Ross, C., & Musacchi, S. (2019). Consumer perception of d'Anjou pear classified by dry matter at harvest using near‐infrared spectroscopy. International Journal of Food Science & Technology, 54(6), 2256-2265.
1. Goke, A., Serra, S., & Musacchi, S. (2018). Postharvest dry matter and soluble solids content prediction in d’Anjou and Bartlett pear using near-infrared spectroscopy. HortScience, 53(5), 669-680.
News
Seeking Collaborators/Software Testers!
StickWatR is a graphical user interface I am developing for the measurement of plant hydraulic conductance based on the Sperry hydraulic apparatus. Powered by R/Shiny, StickWatR's point-and-click interface creates a user-friendly experience that streamlines and simplifies data collection - no coding knowledge required! Features include real-time visualization of flow rates, user-defined criteria for determining stability, data validation checks, and automatic calculation of specific conductance and conductivity that can be exported to easy-to-manage Excel files. StickWatR currently supports data inputs from Sensirion liquid flow sensors. I am seeking collaborators to expand StickWatR's functionality with different forms of data inputs (e.g., various models of analytical balances). If you use balances or other models of flow meters in your hydraulic apparatus and are interested in developing this program with me, let's connect!
Fungal Foray
I am thrilled to be joing the lab of Dr. Anna Sala, at the University of Montana to "dig" in to the rhizosphere and investigate the role of mycorrhizal networks on mediating drought responses in ponderosa pine forests!
I did the thing!
I succesfully defended my masters thesis titled "Drought Responses of Subalpine Forest Tree Seedlings in the Colorado Front Range". Thank you to my advisor, Dr. Patrick Martin, my committee, and all others who supported me along the way!
Christmas in the Dominican Republic
Happy Holidays from our field crew to yours!
Cosmic on TV
CBS Sunday Morning stopped by TFREC to record us running quality on Cosmic Crisp®. Watch the full segment here.
Contact Me
Alex Goke
Biodiversity Research Center, Room 3122212 Main MallVancouver, British Columbia, Canadaalex.goke~at~botany.ubc.ca
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