Evaluating models of shortwave radiation below Eucalyptus canopies in SE Australia

Abstract

In this study we examine the performance of four models that simulate radiation under forest canopies. The models are different in terms of how transmittance of radiation is conceptualised and the data sources used to obtain parameters. Two models (PAIMS and PAINC models) use plant area index (PAI) to represent transmission. A third model (PL model) represents transmission as a function of the path length (L) of a directional beam as it crosses the canopy. The fourth model (LPI model) is based on a light penetration index obtained directly from lidar. The PAIMS and PL models were calibrated using 6 months of radiation data at 4 independent sites. The LPI and PAINC models are uncalibrated. Pe..