Much of my research focuses on the ecophysiology of maple sugaring, including the effects of tapping and carbohydrate extraction on tree growth and health, the physiology of stem pressure and carbohydrates in xylem sap, and ultimately on helping to develop management practices and tapping guidelines to ensure the long-term sustainability of maple syrup production. Recently, my work expanded to include studying the physiology of stem pressure development in birch trees, and investigating sap yields and the potential profitability of adding birch syrup production to existing maple operations in the Northeastern US.

Another area of my research focuses on the chemical composition and flavor of maple syrup, particularly on gaining a better understanding of the compounds important to its flavor profile, and on how factors such as the environment, processing technologies, and management practices might affect its composition and flavor. Most recently, we have studied the impacts of modern sap processing technologies, such as reverse osmosis, on the composition and flavor of the maple syrup produced.

I also study the ecophysiology of anthocyanin pigments, particularly the potential effects of climate change on the development of the anthocyanin pigments in autumn senescing leaves that are responsible for the highly-prized display of autumn coloration in the mountains.

• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Haynes, B.M., and Bosley, W.T. Nonconductive wood associated with taphole wounds in sugar maple (In preparation)
• Perkins, T.D. and A.K. van den Berg. 2022. Ask Proctor: Why does the sap stop running after a few days if it doesn’t freeze again? The Maple Digest (In press).
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Haynes, B.M., and Bosley, W.T. 2022. Total yields from red maple trees. CDL’s Way Spring 2022 (2) 22-23.
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Haynes, B.M., and Bosley, W.T. 2022. Rendement total des érables rouges. La Technique CDL (2) 22-23.
• Perkins, T.D., Bosley, W.T., van den Berg, A.K., and Abair, S.J. 2022. Early spout deployment doesn’t impact sap yield. The Maple News July 2022: 10.
• Stockie, J.M., van den Berg, A.K., Perkins, T.D., and Wilmot, T.R. 2022. Exudation pressure in maple trees: Comparing simulations with experiments. Maple Digest 61(2): 9-17.
• Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K. (Editors). 2022. North American Maple Syrup Producers Manual. Third Edition. University of Vermont and the North American Maple Syrup Council, Burlington, VT. 434 p. https://mapleresearch.org/pub/manual/
• van den Berg, A.K., Boutin, J., and Perkins, T.D. 2022. Chapter 7: Sap and Syrup Processing. In North American Maple Syrup Producers Manual., 3rd ed. Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K., Eds. University of Vermont and the North American Maple Syrup Council, Burlington, VT.
• Hopkins, K., Graham, G., Bailey, P., van den Berg, A.K., and Wightman, A. 2022. Food Safety for maple Producers. In North American Maple Syrup Producers Manual., 3rd ed. Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K., Eds. University of Vermont and the North American Maple Syrup Council, Burlington, VT.
• Perkins, T.D., van den Berg, A.K., Boutin, J., Childs, S., Wilmot, T.W. 2022. Chapter 6: Sap Collection. In North American Maple Syrup Producers Manual., 3rd ed. Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K., Eds. University of Vermont and the North American Maple Syrup Council, Burlington, VT.
• Isselhardt, M.L., Marckres, H., Perkins, T.D., and van den Berg, A.K. 2022. Chapter 8: Syrup Filtration and Grading. In North American Maple Syrup Producers Manual., 3rd ed. Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K., Eds. University of Vermont and the North American Maple Syrup Council, Burlington, VT.
• Smallidge, P.J., Isselhardt, M.L., D’Amato, A., Graham, G., Heiligmann, R.B., and Perkins, T.D., and van den Berg, A.K. 2022. Chapter 5: Sugarbush Management for Syrup Production and Forest Health. In North American Maple Syrup Producers Manual., 3rd ed.
• Perkins, T.D., Heiligmann, R.B., Koelling, M.R. and van den Berg, A.K., Eds. University of Vermont and the North American Maple Syrup Council, Burlington, VT.
• Perkins, T.D. and A.K. van den Berg. 2021. Ask Proctor – Defoamer. The Maple Digest 60(3): 36.
• van den Berg, A.K., Perkins, T.D., Larsen, M.D., Bosley, W.T., and Haynes, B.M. 2021. Yields from early tapping and taphole “rejuvenation” strategies. The Maple Digest 60(4): 13-26.
• Perkins, T.D., van den Berg, A.K., and Bosley, W.T. 2021. Timing of spout and dropline deployment has no effect on sap yield. The Maple Digest 60(3): 9-12.
• van den Berg, A.K., Perkins, T.D., Bosley, W.T., Haynes, B.M., and Isselhardt, M.L. 2021. Wound response to taphole rejuvenation practices. The Maple Digest 60(2): 9-17.
• Perkins, T.D., van den Berg, A.K., and Haynes, B.M. 2021. Why the sap may not always flow well in the early season. The Maple News May: 6-7.
• Perkins, T.D., van den Berg, A.K., and Bosley, W.T. 2021. Effects of tapping depth on sap volume, sap sugar content, and syrup yield under high vacuum. The Maple Digest 60(1): 8-12.
• Cannella, M., Isselhardt, M., van den Berg, A.K., D’Amato, A., and Lindgren, C. 2021. The Northeast Maple Economy: Crop Distribution and Outlook. The Maple Digest 60(1): 19-26.
• van den Berg, A.K., Isselhardt, M.L., and D’Amato, A. 2021. Red maple as crop trees for maple syrup production. Web resource: https://blog.uvm.edu/farmvia/files/2021/01/Red-maple-as-crop-trees-for-maple-production.pdf
• Perkins, T.D., van den Berg, A.K., and Isselhardt, M.L. 2021. Sap flow, wounding and compartmentalization in maple The Maple News 20(3): 10-11.
• Perkins, T.D. and van den Berg, A.K. 2020. Taking care of the woods. Leader Evaporator 2021 Catalog.
• Perkins, T.D., van den Berg, A.K., and Bosley, W.T. 2020. Sap sugar within, between seasons at UVM PMRC. The Maple News 19(10): 25.
• Perkins, T.D. and van den Berg, A.K. 2020. Quick Tips to Achieve High Sap Yield. The Maple News 19(8): 8.
• Perkins, T.D., van den Berg, A.K., and Isselhardt, M.L. 2020. UVM PMRC & Extension Update. Vermont Maple Sugar Makers Association Newsletter. August 2020.
• Perkins, T.D. van den Berg, A.K. and Bosley, W.T. 2020. The Goldilocks Touch — Overdriving Spouts Reduces Sap Yield. The Maple Digest 18(9): 1,26.
• van den Berg, A.K. and Perkins, T.D. 2020. Identifying an Effective Defoamer for Certified Organic Maple Production. The Maple Digest 59(1): 8-23.
• Perkins, T.D. and van den Berg, A.K. 2019. Sanitation, Clogging, or Both: A Comparison Study of 3/16” and 5/16” Maple Tubing. The Maple Digest 58(4): 8-13.
• Perkins, T.D. and van den Berg, A.K. 2019. Ask Proctor: The North American Maple Syrup Producers Manual. The Maple Digest 58(3): 26.
• Perkins, T.D., van den Berg, A.K., and Childs, S.L. 2019. A Decade of Spout and Tubing Sanitation Research Summarized. The Maple Digest 58(3): 8-15.
• Perkins, T.D. and van den Berg, A.K. 2019. Comparison of 3/16” and 5/16” tubing sanitation. The Maple News 18(10): 1,24-25.
• Perkins, T.D., Bosley, W.T., and van den Berg, A.K. 2019. The Goldilocks Touch – Overdriving Spouts Reduces Sap Yield. The Maple News 18(9): 1, 29.
• Perkins, T.D. and van den Berg, A.K. 2019. Effect of spout diameter on sap yield. The Maple News August: 5.
• Perkins, T.D., van den Berg, A.K., and Childs, S.L. 2018. Assessing strategies for spout and drop sanitation in 5/16” tubing: Sap yield, cost, and net profit. The Maple Digest 57(3): 9-13.
• Isselhardt, M.L., Perkins, T.D., and van den Berg, A.K. 2018. Tree size and maple production. New England Soc. Amer. Foresters News Quarterly 79(2): 5-6.
• Perkins, T.D., van den Berg, A.K., Stowe, B., and Bosely, W. 2018. Check-Valve Spouts vs Standard Clear Spouts: A Multi-Year Comparison of Yield in 5/16” Tubing. The Maple News Aug-Sept: 10-11.
• Perkins, T.D., van den Berg, A.K., Stowe, B., and Bosely, W.T. 2018. High brix syrup processing – first two seasons with Lapierre HyperBrix. Maple Syrup Digest 57(2):8-13.
• Perkins, T.D., van den Berg, A.K., Isselhardt, M.L., Stowe, B., and Bosely, W. 2018. Does color matter? The Maple News June-July: 9.
• Perkins, T.D. and van den Berg, A.K. 2018. Relationship between slope position, vacuum, and potential yield in 3/16” tubing systems. The Maple News March: 20-21.
• Isselhardt, M.L., Perkins, T.D., and van den Berg, A.K. 2018. Tree size matters. Maple Syrup Digest 57(1):36-38.
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Godshall, M.A. and Lloyd, S.W. 2012. Maple syrup production with sap concentrated to high levels by membrane separation: effects on syrup chemical composition and flavor. International Sugar Journal 114:572-576.
• van den Berg, A.K. 2012. Defining modern, sustainable tapping guidelines for maple syrup production. Northeastern States Research Cooperative, www.nsrcforest.org. 22p.
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Godshall, M.A. and Lloyd, S.W. 2011. Effects of producing maple syrup from concentrated and reconstituted sap of different sugar concentrations. International Sugar Journal 113:35-44.
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Godshall, M.A. and Lloyd, S.W. 2009. Air injection into concentrated maple sap during processing: impact on syrup composition and flavor. Journal of the Science of Food and Agriculture 89:1770-1774.
• van den Berg, A.K., Vogelmann, T.C. and Perkins, T.D. 2009. Anthocyanin influence on light absorption within juvenile and senescing sugar maple leaves – do anthocyanins function as photoprotective visible light screens? Functional Plant Biology 36:793-800.
• Perkins, T.D. and van den Berg, A.K. 2009. Maple syrup – production, composition, chemistry, and sensory characteristics. In Advances in Food and Nutrition Research (Ed. S.L. Taylor), 56:103-144. Academic Press, San Diego, CA, USA.
• van den Berg, A.K., Perkins, T.D., Isselhardt, M.L., Godshall, M.A. and Lloyd, S.W. 2009. Effects of air injection during sap processing on maple syrup color, chemical composition and flavor volatiles. International Sugar Journal 111(1321):37-42.
• van den Berg, A.K. and Perkins, T.D. 2007. Contribution of anthocyanins to the antioxidant capacity of juvenile and senescing sugar maple (Acer saccharum) leaves. Functional Plant Biology 34:714-719.
• Perkins, T.D., Morselli, M.F., van den Berg, A.K. and Wilmot, T.R. 2006. Maple chemistry and quality. In North American Maple Syrup Producers Manual (R.B. Heiligmann, M.R. Koelling, T.D. Perkins, Eds.) pp 294-300. The Ohio State University, Columbus, OH.