Carbon ecosystem services and cellulose income from natural and commercial forests in the Brazilian savanna

Abstract

The history of deforestation within the Brazilian savanna shaped landscapes with anthropic matrices, and silviculture is one of them. Commercial forest management strongly acts on this biome, affecting natural areas of “cerradão”, a forest physiognomy. The loss of this ecosystem decreases the regional potential of carbon capturing and stocking by native plants, an ecological function that contributes to climate change mitigation, recognized as a regulating ecosystem service. On the other hand, human activities which guarantee the supply of provisioning services, such as commercial forests, are important for regional socioeconomic sustainability. Thus, keeping a balanced supply of both services without exceeding their thresholds brings benefits, avoiding irreversible losses for the human society. With this in mind, we aimed to evaluate the capacity of savanna landscapes in contributing to climate regulation by carbon sequestration from natural forests and generating financial incomes from silvicultural activity, in territories with different proportions of natural and commercial forest cover. We define thresholds and tradeoffs between the supply of ecosystem services and cellulose markets. Also, we assessed the role of compositional and structural attributes of the native forests on carbon stock results. The cerradão presents an average aboveground carbon (AGC) stock of 40 MgC.ha−1, while the carbon stock in Eucalyptus plantings with 6–8 years is almost twice this value, despite this contribution be temporary in the landscape. The benefits from native and commercial forests are equivalent in watersheds presenting at least 55% of their territories covered by native forests. The condition for sustaining carbon ecosystem services and still generating financial gains with the same relative value corresponds to CO2 sequestration equal to 90.6 Mg.ha−1 and a gross income of 20.8 × 103 US$ per hectare of Eucalyptus planted for cellulose pulp. The structural features of the native forest remnants on the AGC stock were more effective than compositional attributes, being strongly correlated with the dominance of certain species.