Hurricane effects on the understory light environment of three forest plots in east Texas

The light environment in the understory was characterized by hemispherical canopy photographs before and after a hurricane in three permanent study sites in SE Texas.  Photographs were taken at 1m intervals along two hundred meter transects in the summer of 1999, and the same transects (at 2m intervals) were revistited in late spring 2006, 9 months after Hurricane Rita passed over the area.  Damage levels varied widely by plot (the well-drained upland site was least damaged, and the mesic and bottomland sites were heavily damaged), by specific location in the plot (some areas within each plot were almost untouched and others nearly leveled), and very selectively by height stratum & species (in one area the tallest stems (Pinus taeda) were the only canopy trees left standing).  Understory light increased in most but not all locations, due to a variable combination of outright tree felling and partial canopy damage, the latter already partially offset in some locations by abundant epicormic sprouting of some species.  Overall, the spatial pattern of understory light changed from one with local patchiness comparable to the size of individual tree canopies, to a more coarsely patchy pattern with more spatial autocorrelation on broader spatial scales.