A single-probe heat pulse method for estimating sap velocity in trees

Available sap flow methods are still far from being simple, cheap and reliable enough to be used beyond very specific research purposes. This study presents and tests a new single-probe heat pulse (SPHP) method for monitoring sap velocity in trees using a single-probe sensor, rather than the multi-probe arrangements used up to now. Based on the fundamental conduction−convection principles of heat transport in sapwood, convective velocity (Vh) is estimated from the temperature increase in the heater after the application of a heat pulse (ΔT). The method was validated against measurements performed with the compensation heat pulse (CHP) technique in field trees of six different species. To do so, a dedicated three-probe sensor capable of simultaneously applying both methods was produced and used. Experimental measurements in the six species showed an excellent agreement between SPHP and CHP outputs for moderate to high flow rates, confirming the applicability of the method. In relation to other sap flow methods, SPHP presents several significant advantages: it requires low power inputs, it uses technically simpler and potentially cheaper instrumentation, the physical damage to the tree is minimal and artefacts caused by incorrect probe spacing and alignment are removed.

Saved in:
Bibliographic Details
Main Authors: López-Bernal, Álvaro, Testi, Luca, Villalobos, Francisco J.
Other Authors: Ministerio de Economía y Competitividad (España)
Format: artículo biblioteca
Language:English
Published: John Wiley & Sons 2017-10
Subjects:Convective velocity, Sap flow, Sensor, Single probe, Thermal diffusivity, Water use,
Online Access:http://hdl.handle.net/10261/160054
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100003329
Tags: Add Tag
No Tags, Be the first to tag this record!