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פותח על ידי קלירמאש פתרונות בע"מ -
Inactive xylem can explain differences in calibration factors for thermal dissipation probe sap flow measurements
Year:
2013
Authors :
כהן, שבתאי
;
.
פאודל, אינדירה
;
.
קנטי, טל
;
.
Volume :
33
Co-Authors:
Paudel, I., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Kanety, T., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel, Tomato Category, Costa Exchange, 45 Elm Street, Guyra 2365, NSW, Australia
Cohen, S., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Facilitators :
From page:
986
To page:
1001
(
Total pages:
16
)
Abstract:
Thermal dissipation probes (TDPs) were calibrated in three diffuse porous fruit trees and one ornamental species in the field by comparison with heat pulse probes (nectarine and persimmon), in a greenhouse on lysimeters (apple and persimmon) and in the laboratory by pushing water through cut branches (apple, Peltophorum and nectarine). Two operational methods were used: continuous (constant thermal dissipation, CTD) and discontinuous, or transient, heating (transient thermal dissipation, TTD). Correction for the radial distribution of sap flux density was with an analytical function derived from a linear decrease in flux density with depth, as measured with a multi-depth 'Tmax' heat pulse system. When analyzed with previous calibration factors, the measured sap flow was <50% of actual value. The underestimations were consistent, and calibrations for each species in the field, greenhouse and laboratory gave approximately the same factors. Reasonable values of tree water use were obtained with the new calibration factors. Evidence is provided that even though the xylem was diffuse porous, the underestimations were caused by contact of the probes with inactive xylem along their length. The average portion of probe in contact with inactive xylem, measured in stained branches following laboratory calibrations, was 0.2-0.24. Using the measured fractions to correct temperature differentials between heated and unheated probes for CTD and TTD, based on Clearwater et al. (in Potential errors in measurement of nonuniform sap flow using heat dissipation probes. Tree Physiol 1999;19:681-687) almost completely compensated for the underestimations. Calibrations are given for each species both before and after corrections of temperature differentials, along with a multispecies calibration. These results should be an important step in reconciling many reports of different calibration factors for TDP probes. © 2013 The Author 2013.
Note:
Related Files :
calibration
Flow measurement
Heat pulse
lysimeter
plant exudate
Plant Exudates
sap flow
sweating
temperature
transpiration
עוד תגיות
תוכן קשור
More details
DOI :
10.1093/treephys/tpt070
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
18597
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:22
You may also be interested in
Scientific Publication
Inactive xylem can explain differences in calibration factors for thermal dissipation probe sap flow measurements
33
Paudel, I., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Kanety, T., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel, Tomato Category, Costa Exchange, 45 Elm Street, Guyra 2365, NSW, Australia
Cohen, S., Institute of Soil, Water and Environmental Sciences, A.R.O. Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Inactive xylem can explain differences in calibration factors for thermal dissipation probe sap flow measurements
Thermal dissipation probes (TDPs) were calibrated in three diffuse porous fruit trees and one ornamental species in the field by comparison with heat pulse probes (nectarine and persimmon), in a greenhouse on lysimeters (apple and persimmon) and in the laboratory by pushing water through cut branches (apple, Peltophorum and nectarine). Two operational methods were used: continuous (constant thermal dissipation, CTD) and discontinuous, or transient, heating (transient thermal dissipation, TTD). Correction for the radial distribution of sap flux density was with an analytical function derived from a linear decrease in flux density with depth, as measured with a multi-depth 'Tmax' heat pulse system. When analyzed with previous calibration factors, the measured sap flow was <50% of actual value. The underestimations were consistent, and calibrations for each species in the field, greenhouse and laboratory gave approximately the same factors. Reasonable values of tree water use were obtained with the new calibration factors. Evidence is provided that even though the xylem was diffuse porous, the underestimations were caused by contact of the probes with inactive xylem along their length. The average portion of probe in contact with inactive xylem, measured in stained branches following laboratory calibrations, was 0.2-0.24. Using the measured fractions to correct temperature differentials between heated and unheated probes for CTD and TTD, based on Clearwater et al. (in Potential errors in measurement of nonuniform sap flow using heat dissipation probes. Tree Physiol 1999;19:681-687) almost completely compensated for the underestimations. Calibrations are given for each species both before and after corrections of temperature differentials, along with a multispecies calibration. These results should be an important step in reconciling many reports of different calibration factors for TDP probes. © 2013 The Author 2013.
Scientific Publication
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