Influence of ecological group composition, plantation spacing and arrangement in the restoration of riparian forest on reservoir shores/Influencia da composicao de grupos ecologicos, espacamento e arranjo de plantio na recuperacao de matas ciliares em margem de reservatorio

This work aimed to assess the effect of spacing, arrangement and ecological group composition of planted seedlings on the restoration process of artificial reservoir shores in southeastern Brazil. The assessments were performed 12 years after the settlement of the experiment in which five mixed stand models were tested. First, a general evaluation of the stand was performed when we surveyed the overstory and understory, seed bank and soil for chemical analysis.Then, the restoration indicators survival of planted trees, basal area and density of the tree community, litter accumulated on the soil and canopy closure index were utilized to compare the plantation models and to assess the influence the experimental factors on these parameters. In the general analysis, we found that the studied stand presents low diversity, poor regeneration, and seed bank dominated mostly by one planted exotic tree species and weeds, which may jeopardize the selfmaintenance of the stand in the future. The factor that most influenced the models was the ecological group composition with the best performance found for models in which both pioneer and non-pioneer groups were used. Probably, the plantation arrangement and spacing did not have greater influence due to both plant mortality and natural regeneration that has developed to this age. Hence, it is not recommended the use of only pioneer species in the implantation of riparian forest and the proportion of 50% pioneers and 50% non-pioneers using as much species as possible is indicated for areas that might present constraints for the natural regeneration. Keywords: Environmental afforestation; restoration indicators; hydroelectric power plants. Este trabalho teve como objetivo avaliar o efeito do espacamento, arranjo e composicao de grupos ecologicos das mudas plantadas no processo de restauracao de margem de reservatorio artificial no sudeste do Brasil. As avaliacoes foram realizadas 12 anos apos a implantacao do experimento em que cinco modelos de plantios mistos foram testados. Primeiramente, fez-se uma avalicao geral do povoamento por meio de levantamentos do estrato arboreo, regenerante, banco de sementes e de analise quimica e textural do solo. Em seguida, lancou-se mao dos indicadores de recuperacao sobrevivencia das arvores plantadas, area basal e densidade da comunidade arborea, acumulo de serapilheira sobre o solo e indice de fechamento do dossel para comparar os modelos e checar a influencia dos fatores experimentai