EXTENSION AND STRUCTURE OF MANGROVE FORESTS IN THE BAJA GUAJIRA, COLOMBIAN CARIBBEAN

Abstract

cover and structural attributes of mangrove forests in the Baja Guajira were estimated and identified. Forest cover was estimated from ASTER images and aerial photographs. The forest structure was evaluated along transects which were 10 m broad and as long as the width of the mangrove fringe. In each transect mangrove trees were identified and counted. The total height and the diameter at breast height (DBH) of the trees were measured and subsequently the basal area, density and Importance Value Index (IVI) calculated. The estimated mangrove cover of the Baja Guajira was 59.9 ha. The most frequent and dominant species was Laguncularia racemosa (0.54 m2.ha-1). Rhizophora mangle was present in 75 % of the stations, while Avicennia germinans was only found in the north of the study area. The highest average heights and diameters for R. mangle, L. racemosa and A. germinans were determined in Rincón Mosquito (12.9±2.3 m and 22.4±11.2 cm), Puerto Brisa (12.2±5.3 m and 20.8±9.8 cm) and La Enea (13.8± 4.3 m and 23.8±14.8 cm), sectors with a constant fresh water supply. The less developed forest, a monospecific forest of Conocarpus erectus, was observed in Dibulla station, with height and diameter averages of 2.8±0.6 m and 3.0±0.9 cm. In terms of natural regeneration, L. racemosa presented the highest proportion of seedlings in the study area, R. mangle was found in stations partly flooded and A. germinans had the highest density of seedlings and propagules at La Enea station.