A Method to Assess Plant Behavior in Green Stormwater Infrastructure

Abstract

There has been a rise in interest to quantify evapotranspiration (ET) in green stormwater infrastructure (GSI), and to do so in easier and cheaper ways than full-scale research sites. This study evaluated using a leaf porometer to estimate ET from plants associated with GSI. The porometer measured water vapor as it transpired from a small portion of a leaf’s surface, which was compared to lysimeter-scale ET calculated via a mass balance method. Twelve vegetated lysimeters planted with black chokeberry, seaside goldenrod, or switchgrass were measured over time for stomatal conductance and lysimeter weight. Fairly strong and statistically significant correlations were observed between ET and stomatal conductance in the lysimeters growing black chokeberry and seaside goldenrod between June 12 and August 28, 2018 [r(15)=0.85, p<0.01]. This study demonstrates the utility of stomatal conductance in describing plant performance in GSI. Conveniently taken stomatal conductance measurements have the capability of being scaled up to describe ET at the GSI scale if they are paired with an approximation of total leaf area.