Measuring the vertical profile of leaf wetness in a forest canopy

Plant canopies are wet for substantial amounts of time and this influences physiological performance and fluxes of energy, carbon and water at the ecosystem level. Leaf wetness sensors enable us to quantify the duration of leaf wetness and spatially map this to canopy structure. However, manually analysing leaf wetness data from plot-level experiments can be time-consuming, and requires a degree of subjective judgement in delineating wetness events which can lead to inconsistencies in the analysis. Here we: Describe how to set up an array of leaf wetness sensors (Phytos 31, Meter) enabling the measurement of leaf wetness duration through the profile of a forest canopy, Present a method and R script to objectively identify and distinguish periods of rain and dew from the output of leaf wetness sensors, Provide a criteria for separating the leaf wetness sensor output into dew and rain events which may form a reference standard, or be modified for use, in future studies. (C) 2021 Published by Elsevier B.V.

Automated summary

Plant canopies being wet for extended periods affects physiological performance and ecosystem energy, carbon, and water fluxes. Leaf wetness sensors can quantify wetness duration and map it spatially to canopy structure. Manual analysis of data from plot-level experiments may be time-consuming and subjective, leading to inconsistencies.