A validation, comparison and error analysis of two heat-pulse methods for measuring sap flow in Eucalyptus marginata saplings

2004 ◽  
Vol 31 (6) ◽  
pp. 645 ◽  
Author(s):  
Timothy M. Bleby ◽  
Stephen S. O. Burgess ◽  
Mark A. Adams
Keyword(s):  
Sap Flow ◽  
Woody Species ◽  
Pulse Method ◽  
Heat Pulse ◽  
Random Fluctuation ◽  
Ratio Method ◽  
Threshold Velocity ◽  
Sapwood Area ◽  
Eucalyptus Marginata ◽  
Significant Difference

We validated and compared two heat-pulse methods for measuring sap flow in potted Eucalyptus marginata Donn ex. Smith (jarrah) saplings. During daylight hours and under well-watered conditions, rates of sap flow (0.1–0.5 kg h–1) measured by the established compensation heat-pulse method (CHPM) and the newly developed heat-ratio method (HRM) were similar to rates measured with a weighing lysimeter, and most of the time there was no significant difference (P<0.001) between methods. The HRM accurately described sap flow at night when rates of flow were low (< 0.1 kg h–1) or near zero, but the CHPM was unable to measure low rates of sap flow due to its inability to distinguish heat-pulse velocities below a threshold velocity of 0.1 kg h–1 (3–4 cm h–1). The greatest potential for error in the calculation of daily sap flow was associated with the misalignment of temperature sensors, the estimation of sapwood area and the method used to acquire total sap flow from point measurements of sap velocity. A direct comparison of the two heat-pulse methods (applied synchronously) revealed that the HRM had a more convincing mechanism for correcting spacing errors and was more resistant to random fluctuation in measurements than the CHPM. While we view the HRM more favourably than the CHPM in some key areas, both methods are valid and useful, within their constraints, for measuring transpiration in jarrah and other woody species.

Improvement of the heat pulse method for determining sap flow in trees

1981 ◽  
Vol 4 (5) ◽  
pp. 391-397 ◽  
Author(s):  
Y. COHEN ◽  
M. FUCHS ◽  
G. C. GREEN
Keyword(s):  
Sap Flow ◽  
Pulse Method ◽  
Heat Pulse

A laser-diode-based system for measuring sap flow by the heat-pulse method

2002 ◽  
Vol 110 (4) ◽  
pp. 275-284 ◽  
Author(s):  
William L. Bauerle ◽  
Thomas H. Whitlow ◽  
Clifford R. Pollock ◽  
Edward A. Frongillo
Keyword(s):  
Laser Diode ◽  
Sap Flow ◽  
Pulse Method ◽  
Heat Pulse

HEAT PULSE METHOD AND SAP FLOW FOR MEASURING TRANSPIRATION IN CACAO

2013 ◽  
Vol XII (2) ◽  
pp. 85-96 ◽  
Author(s):  
Rutilo López-López ◽  
◽  
Waldo Ojeda-Bustamante ◽  
Alejandro P. López Andrade ◽  
Ernesto A. Catalán-Valencia
Keyword(s):  
Sap Flow ◽  
Pulse Method ◽  
Heat Pulse

Improved theory for calculating sap flow with the heat pulse method

2004 ◽  
Vol 126 (1-2) ◽  
pp. 169-173 ◽  
Author(s):  
Gerard J. Kluitenberg ◽  
Jay M. Ham
Keyword(s):  
Sap Flow ◽  
Pulse Method ◽  
Heat Pulse

scholarly journals Calibration of sap flow estimated by the compensation heat pulse method in olive, plum and orange trees: relationships with xylem anatomy

2006 ◽  
Vol 26 (6) ◽  
pp. 719-728 ◽  
Author(s):  
J. E. Fernandez ◽  
P. J. Duran ◽  
M. J. Palomo ◽  
A. Diaz-Espejo ◽  
V. Chamorro ◽  
...  
Keyword(s):  
Sap Flow ◽  
Pulse Method ◽  
Heat Pulse ◽  
Xylem Anatomy ◽  
Orange Trees

scholarly journals Design and implementation of a low-cost device for measuring sap flow in woody species

DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 214-220
Author(s):  
María Fernanda Cárdenas ◽  
Cristina López Ramírez ◽  
Juan Diego Mejía ◽  
Jhon Fredy Escobar
Keyword(s):  
Sap Flow ◽  
Flow Measurement ◽  
Electronic Circuit ◽  
Low Cost ◽  
Storage System ◽  
Woody Species ◽  
Ratio Method ◽  
Ecosystem Level ◽  
Plant Level ◽  
And Storage

Transpiration is a key variable in water balance. Sap flow measurement methods allow to estimate transpiration at plant level, but scalable at the stand, river basin or ecosystem level. This requires recording data continuously, for which there are commercial devices, but they are specialized and expensive. This document shows that it is possible to integrate a data capture, management and storage system, as a counterpart to a commercial system such as Campbell's CR-100, for measuring and recording environmental variables, with a notable reduction in costs. The methodology used to develop a device for the estimation of sap flow using the heat ratio method, the design of the Arduino-based  electronic circuit and the software, with register 13-64-171 of the Dirección Nacional de Derechos de Autor, is presented.

scholarly journals An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems

2009 ◽  
Vol 32 (12) ◽  
pp. 1652-1663 ◽  
Author(s):  
MICHAEL J. CLEARWATER ◽  
ZHIWEI LUO ◽  
MARIAROSARIA MAZZEO ◽  
BARTOLOMEO DICHIO
Keyword(s):  
Sap Flow ◽  
Small Diameter ◽  
Pulse Method ◽  
Heat Pulse ◽  
External Heat ◽  
Flow Through

Evaluating the potential of a novel dual heat-pulse sensor to measure volumetric water use in grapevines under a range of flow conditions

2014 ◽  
Vol 41 (8) ◽  
pp. 874 ◽  
Author(s):  
Kyle R. Pearsall ◽  
Larry E. Williams ◽  
Sean Castorani ◽  
Tim M. Bleby ◽  
Andrew J. McElrone
Keyword(s):  
Water Use ◽  
Sap Flow ◽  
Heat Pulse ◽  
Low Flow ◽  
Ratio Method ◽  
Flow Conditions ◽  
Thompson Seedless ◽  
Flow Measurements ◽  
Highly Correlated ◽  
Weighing Lysimeter

The aim of this study was to validate a novel, dual sap-flow sensor that combines two heat-pulse techniques in a single set of sensor probes to measure volumetric water use over the full range of sap flows found in grapevines. The heat ratio method (HRM), which works well at measuring low and reverse flows, was combined with the compensation heat-pulse method (CHPM) that captures moderate to high flows. Sap-flow measurements were performed on Vitis vinifera L. (cvv. Thompson seedless, Chardonnay and Cabernet Sauvignon) grapevines growing in a greenhouse and in three different vineyards, one of which contained a field weighing lysimeter. The combined heat-pulse techniques closely tracked diurnal grapevine water use determined through lysimetry in two growing seasons, and this was true even at very high flow rates (>6 L vine–1 h–1 for Thompson seedless vines in the weighing lysimeter). Measurements made with the HRM technique under low flow conditions were highly correlated (R2 ~ 0.90) with those calculated using the compensated average gradient method that is used to resolve low flow with the CHPM method. Volumetric water use determined with the dual heat-pulse sensors was highly correlated with hourly lysimeter water use in both years (R2 = 0.92 and 0.94 in 2008 and 2009 respectively), but the nature of the relationship was inconsistent among replicate sensors. Similar results were obtained when comparing grapevine water use determined from sap-flow sensors to miniaturised weighing lysimetry of 2-year-old potted vines and to meteorological estimates for field-grown vines in two additional vineyards. The robust nature of all of the correlations demonstrates that the dual heat-pulse sensors can be used to effectively track relative changes in plant water use, but variability of flow around stems makes it difficult to accurately convert to sap-flow volumes.

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