Atlantic Forest recovery after long-term eucalyptus plantations: The role of zoochoric and shade-tolerant tree species on carbon stock

Abstract

Currently, about a third of the world’s forest areas that have been deforested are regrowing. These second-growth forests (SGF) promote carbon stocks and tree species richness recovery (co-benefits recovery), which is central to mitigating the negative impact of climate change and loss of biodiversity. In Brazil’s Atlantic Forest, second-growth forests that are regrowing after long-term land use can recover diversity and carbon and can have important carbon-tree diversity co-benefits. Thus, we evaluate the recovery of tree species richness and above-ground carbon stock (AGC) in SGF that are regrowing after a long-period of eucalyptus plantations. For this we sampled 43 SGF with stand ages varying from 1−32 years after eucalyptus plantations cutting and three reference old-growth forests (OGF). We considered all individuals with more than 15 cm of circumference at breast height in one 20 × 50 m plot by patch. We identified all tree species, which were categorized into functional attributes, such as zoochoric and non-zoochoric, pioneer and shade-tolerant, and fleshy and dry fruits species. There were marked differences in species richness and AGC between OGF and SGF, but SGFs were not different between then. However, in 32 years these second-growth forests recovered ∼38% of species richness and ∼14% of carbon stock of old-growth forests. In addition, there was a carbon-biodiversity co-benefits mainly between zoochoric and shade-tolerant species richness. These results showed that these second-growth forests could naturally recover biodiversity and AGC. Possibly, this is due to the connectivity provided by land-use for eucalyptus plantations that induces favorable conditions for the recruitment of zoochoric and shade-tolerant species and thus for the recovery of biodiversity and AGC after eucalyptus cutting. Thus, this second-growth forest management can contribute to Atlantic Forest biodiversity conservation and carbon stock initiatives.