Gutierrez Lopez, Jose
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Abstract
Winter-dormant-season sap flow in deciduous, woody eudicots is important because it’s thought to aid in embolism repair and because sap harvesting for syrup production is carried out in some of these species during winter dormancy. Winter-dormant-season sap flow is largely understudied, though. To advance understanding of the patterns and drivers of winter-dormant-season sap flow, we measured time series of sap flow (sap-flux density) and wood temperature during winter dormancy over three years (2019-2021) in the northeastern USA in deciduous, woody eudicots, many of which are either economically important or promising for syrup production. The goal of this research was to identify critical wood temperatures, or temperatures at which the most sap flow occurs. We used bivariate plots to examine the relationships involving the predictor variables wood temperature and rate of wood temperature change over time and the response variables sap-flux density and rate of sap-flux density change over time. Some study species, such as Fagus grandifolia and Platanus spp., yield sap for syrup production during periods of freezing and thawing, whereas other study species, such as Betula papyrifera and Ostrya virginiana, yield sap for syrup production during times when temperatures are slightly warmer and freezes and thaws are uncommon. Despite these differences, we found that, in nearly all study species, both sap-flux density and rate of sap-flux density over time were largest in magnitude when wood temperatures were near 0°C and when instantaneous rates of wood temperature change over time were negligible. This anomaly leads us to speculate that sap flow may be strongly influenced by liquid-to-solid and solid-to-liquid phase changes, and that stem pressure may be a better predictor of sap yield than sap flow.
Keywords
dormancy; sapwood; sugaring; syrup; xylem
Published in
Acta Horticulturae
2025, volume: 1, number: 1419, pages: 95-104
Title: Proceedings of the XII International Workshop on Sap Flow
Publisher: International Society for Horticultural Science
Conference
XII International Workshop on Sap Flow, 2023, 31 October-3 November, Rotorua, Aotearoa, New Zealand
SLU Authors
UKÄ Subject classification
Forest Science
Wood Science
Publication identifier
- DOI: https://doi.org/10.17660/ActaHortic.2025.1419.13
- ISBN: 0567-7572
- eISBN: 2406-6168
Permanent link to this page (URI)
https://res.slu.se/id/publ/142908