The objective of this study was to evaluate three
techniques for quantifying canopy openness within
stands of tropical trees with diverse canopy architectures
and to compare the usefulness of canopy openness
or gap fraction thus measured as a predictor of
measured mid-day transmission of PAR. It was hypothesized
that an effective method should be able
to indicate that a managed canopy is transmitting between
40 and 60% PAR as currently indicated as optimal
for shade-tolerant crops under most conditions