Improvement of the trunk heat balance method including measurement of zero and reverse sap flows

Features of Scots Pine Mortality Due to Incursion of Pine Bark Beetles in Symbiosis with Ophiostomatoid Fungi in the Forest-Steppe of Central Siberia

“…Further, all initial data were preprocessed in a few steps, including verification, correction of errors, and noise reduction by averaging to hourly mean values. Preprocessing raw sap flow data also included correction of Q values considering heat losses from the point of measurements to the environment, known as sap flow baseline [31], and averaging to hourly time series. In 2020, after the death of tree PP1, monitoring instruments were installed in tree PP10.…”

In situ observation of thermal and hydraulic responses of sunflower stem to cold water irrigation using embedded thermocouples

“…On the other hand, the hydraulic connectivity between the soil water reservoir and the plant water pathway relies on a negative water potential gradient created by leaves water transpiration. For comprehensively investigating the plant-water relation, various sensing techniques have been developed, such as those for leaf stomatal conductance (Friend et al, 1989;Steppe et al, 2006;Blonquist et al, 2009), leaf water potential (Turner and Long, 1980;Zimmermann et al, 2008), leaf temperature (Hashimoto et al, 1984;Rahkonen and Jokela, 2003;Gontia and Tiwari, 2008), leaf thickness (Li et al, 2009;Seelig et al, 2012), stem water potential (Choné et al, 2001;Yang et al, 2012), stem diameter variation (Fernández and Cuevas, 2010), stem sap flow rate (Č ermák et al, 1973;Bakfr and Van Bavel, 1987;Smith and Allen, 1996;Trcala and Č ermák, 2012), stem water content (Wullschleger et al, 1990;Irvine and Grace, 1997) and root water potential/pressure (Fiscus, 1972;De Swaef et al, 2013). However, even though these sensors provide different physiological information to support insights into plant water status, none provides a single measure that is well correlated with the numerous factors influencing plant water stress (Kramer, 1988).…”

Finite element analysis of the sap flow measurement method with continuous needle heating in the sapwood of trees

“…These simulations were obtained by COMSOL Multiphysics with MATLAB and are based on solving partial differential equation by the finite element method. The partial differential equation is the following [23,24]:…”

“…This is why several methods for field measurement of the ascending water flow (sap flow) through a plant stem were developed (presented in chronological order): (1) heat pulse velocity [2, 5, 6, 8-10, 11, 14, 15, 21, 25]; (2) trunk segment heat balance [3,4,23,24]; (3) stem heat balance [1,19,20]; (4) heat dissipation [7]; and (5) heat field deformation [16][17][18]. These methods are thermodynamic (in practice only thermodynamic methods for sap flow measurement are used) and are based on the same physical principle.…”