Impact of Bambusa tuldoides Munro (Poaceae) on forest regeneration

Abstract

Bamboo grove may cause changes in the structure and floristic composition of natural regeneration. This study evaluated the impact caused by Bambusa tuldoides Munro at natural regeneration, in riparian forest in Rio Grande do Sul, south of Brazil. Two areas were evaluated: riparian forest without bamboos (SB) as the reference area, and riparian forest dominated by Bambusa tuldoides (CB). In 2014, ten plots (10x10 m) were installed in each area. All individuals belonging to classes I (30≤ H <130 cm) and II (CBH≤5 cm) were measured and identified. Floristic composition, phytosociological indexes, Shannon diversity index, Margalef richness, Simpson dominance, Sorensen similarity, and cluster analysis by Twinspan were evaluated. Richness and absolute density decreased in CB compared to SB. The areas presented low floristic similarity, and high dominance of one or more species in both classes. Myrtaceae was the predominant botanic family in SB, especially Campomanesia xanthocarpa. In CB most species were secondary, as Myrsine umbellata, Cupania vernalis, and Ocotea puberula. Due to the large differences between SB and CB, the groups formed were restricted mostly to the species of each area. Species such as Myrsine umbellata (class I and II) and Strichnos brasiliensis (class II) appear as indicators and former of groups in CB. We concluded that high density of Bambusa tuldoides affect the richness and diversity of regeneration natural, changing the establishment and perpetuation of the species. Secondary species show greater potential for adaptation to these environments and can act as key species in management and recovery actions.