Maranthaceae overabundance decreases richness and abundance of regenerating woody plants in natural gaps

Abstract

Natural gaps are known to be one of the most common disturbance types in tropical forests. Maranthaceae is one of the most important herb families and some studies on gaps address the influence of herbs on the regeneration of shrubs and trees. Maranthaceae are common and sometimes dominant herbs in tropical forest gaps. In this study we investigated the impact of Maranthaceae overabundance on the regeneration of woody species in natural gaps in a bamboo-dominated (Guadua weberbaueri Pilg; Poaceae) forest fragment in southwestern Amazonia. We sampled 20 natural gaps, where Maranthaceae and woody plants with height ≥ 1 m and DBH ≤ 10 cm were counted, measured and identified. We used NMDS for species composition analyses and a GLM to test the influence of Maranthaceae overabundance on woody species richness and abundance. We also measured the similarity of woody species richness and abundance among Maranthaceae dominated and non-dominated gaps. The NMDS shows a distinction between Maranthaceae dominated and non-dominated gaps. The overabundance of Maranthaceae reduced significantly the richness and abundance of woody species. Species composition was also dissimilar among gaps and was influenced by Maranthaceae overabundance.