OOS 53-4 - Manipulating plant assembly to improve restoration of Subtropical Forests

Abandoned pasture areas represent risks to the integrity of many global biomes. In subtropical forests, the scenario is no different, often demanding for active restoration interventions. Manipulating assembly can create positive priority effects that can be used to foster restoration. In this talk we present the results of an ongoing field experiment that aims to understand the effects of manipulating assembly of tree species on restoration success of an abandoned pasture in the Atlantic Forest biome. By establishing the first priority effect field experiment in subtropical forests we manipulated the planting of selected species, aiming to discover which functional group has the potential to promote restoration more effectively. The functional groups established were: Legume Species with Good Shading (LGS), Legume with Bad Shading (LBS), Non-Legume with Good Shading (NLGS), and Non-Legume with Bad Shading (NLBS). For each of these groups, two individuals of three native tree species were planted in a randomized distribution within each plot, in a total of six replications and two controls (first and second planting phases). The simultaneous and sequential treatments differed by a planting interval of one year. Preliminary results indicate that species differed in their relative growth rate (RGR of base diameter, total height and canopy volume) regardless of the functional group or the control group. After 24 months, the seedlings of the NLGS group had the highest RGR in almost all evaluated parameters when compared with other functional groups. Also, considering the effects of the first planting on the growth of seedlings from the second planting, the seedlings growing below the NLGS group had the highest RGR (height, diameter, canopy volume) and the seedlings growing below the LGS group the lowest growth. These preliminary results indicate possible positive priority effects of the NLGS and negative priority effects of the LGS functional group on the seedlings arriving later in the assembly. These results highlight that the manipulation of seedlings' arrival can affect the results of restoration projects.