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

Abstract

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.

Prediction model for sap flow in cacao trees under different radiation intensities in the western Colombian Amazon

“…Diurnal sap flow measurements are costly, both in terms of equipment and data post-processing 30 , 31 . Thus, some efforts have been made to model diurnal sap flow, such as the Jarvis-type model 32 , which predicts sap flow by using non-linear models that depend on a single environmental factor (e.g., photosynthetically active radiation or vapor pressure deficit 16 , 18 ) or a group of environmental variables 33 .…”