INFLUENCE OF ECOLOGICAL GROUP COMPOSITION, PLANTATION SPACING AND ARRANGEMENT IN THE RESTORATION OF RIPARIAN FOREST ON RESERVOIR SHORES

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.Este trabalho teve como objetivo avaliar o efeito do espa\ue7amento, arranjo e composi\ue7\ue3o de grupos ecol\uf3gicos das mudas plantadas no processo de restaura\ue7\ue3o de margem de reservat\uf3rio artificial no sudeste do Brasil. As avalia\ue7\uf5es foram realizadas 12 anos ap\uf3s a implanta\ue7\ue3o do experimento em que cinco modelos de plantios mistos foram testados. Primeiramente, fez-se uma avali\ue7\ue3o geral do povoamento por meio de levantamentos do estrato arb\uf3reo, regenerante, banco de sementes e de an\ue1lise qu\uedmica e textural do solo. Em seguida, lan\ue7ou-se m\ue3o dos indicadores de recupera\ue7\ue3o sobreviv\ueancia das \ue1rvores plantadas, \ue1rea basal e densidade da comunidade arb\uf3rea, ac\ufamulo de serapilheira sobre o solo e \uedndice de fechamento do dossel para comparar os modelos e checar a influ\ueancia dos fatores experimentais nestes par\ue2metros. Como resultado da an\ue1lise geral, obteve-se que o povoamento encontra-se em situa\ue7\ue3o de baixa diversidade, com regenera\ue7\ue3o deficiente e banco de sementes dominado majoritariamente por uma esp\ue9cie arb\uf3rea ex\uf3tica utilizada no plantio e esp\ue9cies herb\ue1ceas invasoras, o que pode comprometer a automanuten\ue7\ue3o do povoamento no futuro. O fator que mais influenciou os modelos foi a composi\ue7\ue3o de grupos ecol\uf3gicos com os melhores resultados apresentados pelos modelos em que se usaram ambos os grupos das pioneiras e n\ue3o pioneiras. Provavelmente, o arranjo e o espa\ue7amento de plantio n\ue3o tiveram muita influ\ueancia devido \ue0 mortalidade das mudas e \ue0 regenera\ue7\ue3o natural que se desenvolveu at\ue9 esta idade. Assim, recomenda-se que na implanta\ue7\ue3o de povoamentos para reconstitui\ue7\ue3o de matas ciliares n\ue3o sejam utilizadas apenas esp\ue9cies pioneiras e sugere-se que a propor\ue7\ue3o de 50% de esp\ue9cies pioneiras e 50% de n\ue3o pioneiras, com o maior n\ufamero poss\uedvel de esp\ue9cies, seja utilizada em \ue1reas com defici\ueancia da regenera\ue7\ue3o natural