par Masumbuko Ndabaga, Céphas ;Muhashy, Céphas Habiyaremye;Meerts, Pierre
Référence Mountains: Geology, Topography and Environmental Concerns, Nova Science Publishers, Inc., page (251-262)
Publication Publié, 2014-04
Partie d'ouvrage collectif
Résumé : The density of lianas in the mountainous rainforest was examined with reference to the topography in the Kahuzi-Biega National Park, in the East of the DR Congo. The studied area was subjected to disturbance assumed to be at the basis of the reduction in the density of trees and a better manifestation of lianas, particularly Sericostachys scandens, in the forest's canopy. The inventory of the trees of dbh (diameter at breast height) ≥ 10 cm was carried out in plots of 20 m × 50 m, whereas all species of lianas of dbh ≥ 1 cm were recorded on squares of 20 m × 20 m along nine different mountains, where the research and monitoring team of the park observed major disturbances in the ecosystem. The mechanisms used by the lianas to climb up the trees were described. The proportion of trees with lianas was determined. The canopy cover was assessed. The results of the inventory include 45 species lianas belonging to 35 genera and 25 families. The twining species are dominant and constitute 40 % of the lianas inventoried. The highest densities of lianas were found more on the slopes of the mountains and less on the peaks and the feet covered by a semi-open canopy. However, the highest proportion of trees with lianas was observed in plots with more open canopies, particularly on the peaks and the feet. This shows that the habitus of the lianas varies visibly with the type of canopy. In dense and closed forests, they tend to crawl on the ground. Otherwise, they adopt a climbing habit within open canopies. Sericostachys scandens, which lacks special anchorage mechanism, seems to benefit from an effect of facilitation by other creepers. Knowledge of the conditions in which this liana develops rapidly in ecosystems appears to be important for the understanding of the dynamics of its expansion.