Survival, seedlings growth and natural regeneration in areas under ecological restoration in a sandy coastal plain (restinga) of southeastern Brazil

Abstract

AbstractRestinga is an ecosystem associated mainly with the Atlantic Forest that can be defined as vegetation of the coastal plain established on sandy soil. This study was carried out in degraded areas of restinga in a Conservation Unit in São João da Barra, Rio de Janeiro, Brazil. In 2012, a restoration project was initiated in the area, with implementation of plantings in hexagonal rings and artificial perches. Seedlings were planted in two contrasting situations: sandbanks (dry areas) and depression zones (areas prone to seasonal flooding). The objective of this study was to evaluate the performance of seedlings planted in both areas and accompany natural regeneration. We hypothesised that species planted and recruited in depressions should have better survival rates and increments in height (H) and diameter at the ground level (DGL) than the ones planted in sandbanks. Monitoring of planted seedlings was carried out in November 2016. Both communities had similar mortality (c. 50%). Greater increments in H were found for Inga laurina and Schinus terebinthifolia in depressions. Higher increments in DGL were observed especially for I. laurina, Inga vera and S. terebinthifolia with good performance in both areas. In general, seedlings planted in depressions showed greater performances, which can be related to higher water and nutrient availability. The most abundant natural regenerant species were Scoparia dulcis in sandbanks and S. terebinthifolia in depressions. A high number of regenerants was found associated with artificial perches, especially Cynophalla flexuosa, which demonstrates that the technique facilitated regeneration in the area.