Estimating gap lifetime and memory from a simple model of forest canopy dynamics.

Gap formation and closure represent important disturbance events in forests, but the processes involved are still poorly understood. We use models, which we and others previously developed, to make long-term predictions of tropical forest gap dynamics based on Barro Colorado Island data. We first fit the models to the data by comparing their discrete Fourier transforms, and we propose a definition for the lifetime of a gap and predict a large-gap lifetime typically to be less than 50 years. We find that the gap lifetime diverges logarithmically for large-gap sizes. We examine the 'memory' of spatial gap patterns via spatiotemporal correlations and find a correlation time of about 160 years, suggesting that present gap patterns could have long-lasting effects on forest spatial patterns.