A Comparison Between Deterministic and Stochastic Evapotranspiration Models for Container Grown Acer Rubrum

Abstract

A lysimeter study was conducted to determine evapotranspiration (ET) rates of Red Maple (Acer Rubrum) under field conditions in Columbus-OH, USA. The average daily measured ET for the plant for two months including all night time data was 998.75 g. This measured ET was compared against Fynn, Stanghellini and Penman’s evapotranspiration models. Fynn and Stanghellini ET model underestimated actual ET rates by 16.32 and 19.74% respectively but Penman model overestimated actual ET rate by 30.99% when excluding night time data and/or data less than 50 g/tree h. R2 values of Fynn, Stanghellini and Penman ET model were 0.644, 0.645 and 0.582 respectively. Simple linear regression analyses showed that a solar radiation or a VPD based stochastic ET model could be successfully used to predict ET in terms of R2 value of 0.758 and 0.647 respectively.