Isolated canopy gaps involving one to several trees occur continuously and frequently in many moist and wet neotropical forests (sensu Holdridge et al.1971), shaping tree community structure through a shifting mosaic of patches of high resource availability for small and young trees (Denslow 1980). Though there are few relevant data (Jans et al. 1993), forests with significant seasonal drought are expected to have lower rates of canopy-gap formation (gaps ha-1 γ-1), smaller gap sizes, and, thus, lower rates of canopy disturbance (%γ-1, see review in Whigham et al. 1999). At the extreme, very dry tropical forests do not appear to fit the gap-phase dynamics concept (Swaine et al. 1990).
