title: The effect of exotic grass Urochloa decumbens (Stapf) R.D.Webster (Poaceae) in the reduction of species richness and change of floristic composition of natural regeneration in the Floresta Nacional de Carajás, Brazil.
abstract: The introduction of exotic species is considered as one of the major causes of biodiversity loss. The National Forest of Carajás is one of the largest mineral provinces in the world. Mining activities caused changes of the natural habitats, leaving degraded areas after the mineral exploitation. One of the mining areas within FLONA Carajás was used for the extraction of gold. In the process of exploitation, a huge depression was formed by the removal of soil which was mounded up nearby. To prevent soil erosion of these mounds, an exotic grass, Urochloa decumbens (Stapf) R.D.Webster (Poaceae) was planted. The objective of this study was to compare the impact of this non-native grass on species richness and species composition of the natural regeneration in the degraded areas. Four areas were compared, two with and two without presence of U. decumbens. In each area, twenty four 1m²/plots were established. Species richness of the regeneration areas and population sizes were significantly lower in the plots where the exotic grass was present. Our study shows that U. decumbens had a negative effect on species richness and population density, and its presence changed the species composition and distribution of life forms of the natural regeneration.
authors.affiliation: Museu Paraense Emílio Goeldi, Coordenação de Botânica, Av. Perimetral, 1901, Terra Firme, 66077 530 Belém, PA, Brasil, Museu Paraense Emílio Goeldi, Coordenação de Botânica, Belém PA , Brasil.
authors.forename: Leandro V
authors.initials: LV
authors.lastname: Ferreira
authors.affiliation: INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France, Université de Nice Sophia-Antipolis, Univ. Nice Sophia Antipolis, Institut Sophia Agrobiotech, Sophia Antipolis , France.|Dept. Biodiversity, Evolution and Ecology of Plants, Biocentre Klein Flottbek, University of Hamburg, Ohnhorststrasse 18, D-22609 Hamburg Germany , Universität Hamburg, Dept. Biodiversity, Evolution and Ecology of Plants, Biocentre Klein Flottbek, University of Hamburg, Hamburg , Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Parolin
authors.affiliation: Museu Paraense Emílio Goeldi, Coordenação de Botânica, Av. Perimetral, 1901, Terra Firme, 66077 530 Belém, PA, Brasil, Museu Paraense Emílio Goeldi, Coordenação de Botânica, Belém PA , Brasil.
authors.forename: Darley C L
authors.initials: DC
authors.lastname: Matos
authors.affiliation: Museu Paraense Emílio Goeldi, Coordenação de Botânica, Av. Perimetral, 1901, Terra Firme, 66077 530 Belém, PA, Brasil, Museu Paraense Emílio Goeldi, Coordenação de Botânica, Belém PA , Brasil.
authors.forename: Denise A
authors.initials: DA
authors.lastname: Cunha
authors.affiliation: Museu Paraense Emílio Goeldi, Coordenação de Botânica, Av. Perimetral, 1901, Terra Firme, 66077 530 Belém, PA, Brasil, Museu Paraense Emílio Goeldi, Coordenação de Botânica, Belém PA , Brasil.
authors.forename: Priscilla P
authors.initials: PP
authors.lastname: Chaves
authors.affiliation: Universidade Federal de Santa Caratina, Laboratório de Ecologia de Anfíbios e Répteis, Campus Universitário, s/n, Sala 219B, Bloco B, 2°andar, Córrego Grande, 88040-900 Florianópolis, SC, Brasil, Universidade Federal de Santa Catarina, Universidade Federal de Santa Caratina, Laboratório de Ecologia de Anfíbios e Répteis, Florianópolis SC , Brazil.
authors.forename: Selvino O
authors.initials: SO
authors.lastname: Neckel
mesh_terms: D044822:Biodiversity; D001938:Brazil; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006046:Gold; D058865:Introduced Species; D008906:Mining; D006109:Poaceae / Q000009:adverse effects* / Q000254:growth & development; D012038:Regeneration; D013045:Species Specificity
chemical_list: D006046:Gold