Use of Eucalytpus mixed with native species for initial reforestation in the Atlantic Forest

Aim of study: With increasing pressure to restore degraded environments, mixed plantations composed of exotic species with economic interest and native species have been identified as an important strategy to attract the interest of farmers. However, knowledge regarding the interactions among and impacts of species in these areas is still lacking. We investigated the effect of introducing Eucalyptus combined with high native species diversity to restore an Atlantic Forest region in Brazil 42 months after planting. Area of study: Restoration of an Atlantic Forest area in Santo Antonio do Amparo, Brazil. We evaluated different proportions of Eucalyptus and native species and the effect of the biodiversity of species on tree growth. Material and Methods: The experiment followed a completely randomised block design with four replicates using a 3 × 19 factorial scheme. The first factor corresponded to the percentage of Eucalyptus plants relative to native species (25%, 33%, and 50%), and the second factor was the species composition. Height, diameter at breast height, biomass, and total carbon were measured at 42 months. We performed an analysis of variance (ANOVA), and when significant differences were detected, the means were compared using the Tukey’s test (5%) for models and the Scott-Knott test (5%) for species. Main results: We observed that with the increase in Eucalyptus density, there was an increase in biomass and carbon stock in the evaluated areas due to the rapid growth of the species. Furthermore, lower Eucalyptus density (33%) reduced intraspecific competition between the individuals, which benefited greater individual growth of Eucalyptus trees. In addition, the development of fast-growing native species was reduced with the increase in Eucalyptus density. Research highlights: Increasing the proportion of Eucalyptus to 25-33% can reduce the costs of restoring Atlantic Forest areas in Brazil while enhancing the financial viability of reforestation through Eucalyptus wood production.