COMPARATIVE STUDY ON THE DRAINAGE REQUIREMENTS AND GROWTH PATTERN OF THREE NEOTROPICAL PIONEER SPECIES

Abstract

The spatial pattern, diameter distribution and height growth pattern of Heliocarpus popayanensis, Ochroma lagopus and Cecropia peltata were studied in logged stands of different ages along a drainage gradient in the Forest Reserve of Caparo, Venezuela. Heliocarpus popayanensis and O. lagopus were rare in the periodically flooded depressions but occurred commonly on well-drained levee sites. In contrast, C. peltata was equally abundant in both drainage types. Heliocarpus popayanensis and O. lagopus occurred only in large disturbed areas (> 300 m²) and hence showed a clumped pattern, whereas C. peltata was found in a wide range of gap sizes, leading to a random distribution in both drainage types. Recruitment as well as height growth in H. popayanensis and O. lagopus ended earlier than in C. peltata. Overall, C. peltata showed a 'generalist' behaviour, while the other species were 'specialists' confined to a narrower ecological niche.