Effect of the invasive liana Sericostachys scandens Gilg and Lopr. (Amaranthaceae) on the spatial structure and recruitment of woody plant species within Kibira National Park in Burundi

Lianas play an important role in several aspects of forest dynamics. This study aims to (1) compare the spatial distribution of woody species between invaded and non-invaded areas by Sericostachy scandens and (2) assess the effect of the density of adult trees of a given species and woody regeneration and young tree stages of other species on the recruitment of the target woody species in both invaded and non-invaded areas by S. scandens within Kibira National Park (KNP) in Burundi. The abundance of woody species (regeneration, young trees, adult trees) was measured in 100 plots of 50 m × 50 m each, evenly distributed in the invaded areas and the non-invaded ones. The analysis of the spatial distribution of woody species was carried out through the computation of the Green index. A multiple regression was performed to test the effect of conspecific adults trees density and the average density of heterospecific woody regeneration and young tree on recruitment of woody species. The Green index values showed that all woody species had a random spatial distribution, regardless of S. scandens invasion. Overall, the density conspecific adults’ trees have a positive or insignificant effect on regenerations and young trees in both invaded and non-invaded areas. New studies focused on the influence of abiotic and biotic factors of the areas are essential for a thorough understanding of the distribution of KNP woody species and the mechanisms of their coexistence.