Inversion of gap frequency data in forest stands

The inversion of gap proportion data for canopy structure variables has bee n widely used in plant canopy analysers. However, the results for most fore st canopies tend to be biased, due to the foliage clustering at different s tructural levels. To invert the gap frequency data in forest stands for the canopy leaf area index, new gap fraction formulas are proposed capable of taking explicitly into account the clustering of foliage into crowns as one of the most important clustering levels. The formulas are based on the giv en mathematical expressions for the crown shape and on the Poisson or binom ial tree distribution patterns. (C) 1999 Elsevier Science B.V. All rights r eserved.