Harvesting intensity affects forest structure and composition in an upland Amazonian forest

• Published in: Forest ecology and management Vol. 169; no. 3; pp. 243 - 255
• Main Authors: Parrotta, John A, Francis, John K, Knowles, Oliver H
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2002; Elsevier
• Subjects: Biological and medical sciences; Brazil; Floristic diversity; Forest harvesting and working in forest; Forest management; Forestry; Fundamental and applied biological sciences. Psychology; Productivity; Regeneration; South America; Brazil; Amazon Basin; America; Productivity; Brazil; Floristic diversity; Regeneration; Forest management; Floristic composition; Upland area; Silviculture; Growth; Tropical zone; Forest tree; Natural forest regeneration; Tropical forest; Vegetation dynamics; Forest logging; Sandy soil; Biodiversity; LOGGING; Environment impact; Harvesting intensity; Silvicultural systems; Vegetation structure
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(01)00758-7

Forest structure and floristic composition were studied in a series of 0.5 ha natural forest plots at four sites near Porto Trombetas in Pará State, Brazil, 11–12 years after being subjected to differing levels of above-ground biomass harvest and removal. In addition to undisturbed control plots, experimental treatments included: removal of most trees ≥45 cm DBH (low intensity harvest); removal of trees <20 and ≥60 cm DBH (moderate intensity harvest); clear-cutting (100% above-ground biomass removal). Post-harvest basal area growth generally increased with harvest intensity, and total basal areas for trees ≥5 cm DBH were, at the time of our study, 60% (in the clear-cut) to about 80% of those in the control plots. Biomass harvests stimulated recruitment and growth of residual trees, particularly in the smaller diameter classes, but had little effect on species richness for small trees, seedlings, vine, herbs, and grasses. Species richness for trees ≥15 cm DBH was greater in the control and low-intensity (74–75 species) than in the moderate intensity (47 species) and clear-cut (26 species) treatment plots. While the tree flora within all harvest treatments was broadly similar to the undisturbed (control) plots and included similar numbers of species of the major plant families typical of the surrounding forests, the more intensive harvest treatments, especially the clear-cut, were dominated by a higher proportion of short-lived, early successional tree species.