Repeated disturbances and canopy disturbance regime in a tropical semi-deciduous forest

• Published in: Journal of tropical ecology 2008-01, Vol.24 (1), p.85-93
• Main Authors: de Lima, Renato A. Ferreira, Martini, Adriana M. Zanforlin, Gandolfi, Sérgius, Rodrigues, Ricardo Ribeiro
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Canopies; Canopy gaps; complex gaps; Deciduous forests; Dry season; Forest canopy; Forest ecology; Forest regeneration; Fundamental and applied biological sciences. Psychology; gap size; Methods; Mortality; Old growth forests; Plant ecology; south-eastern Brazil; Synecology; Terrestrial ecosystems; treefalls; Trees; Tropical forests; Tropical rain forests; turnover rate
• ISSN: 0266-4674; 1469-7831
• DOI: 10.1017/S0266467407004658

The canopy disturbance regime and the influence of gap methods on the interpretation of forest structure and dynamics were evaluated in a tropical semi-deciduous forest in south-eastern Brazil. We encountered a gap density of 11.2 gaps ha−1 and an average size which varied from 121 to 333 m2 depending on the gap delimitation method considered (minimum gap size was 10 m2). Although average size was slightly higher, the median value obtained (78 m2) was comparable to other tropical forest sites and the gap size-class distribution found supported the pattern described for such forest sites. Among 297 gap makers, snapping and uprooting were the most common modes of disturbance. The number and basal area of gap makers were good predictors of gap size. Almost 25% of all gaps suffered from repeated disturbance events that brought about larger gap sizes. Such processes, along with delimitation methods, strongly influenced the estimation of turnover rate and therefore the interpretation of forest dynamics. These results demonstrated the importance of further studies on repeated disturbances, which is often neglected in forest studies.