Notícia

News Bulletin 247

Study quantifies human impact on the carbon retention capacity of the Atlantic Forest (23 notícias)

Publicado em 21 de junho de 2022

Por Robert

Among the many benefits of native forests is the great potential to store carbon in the biomass of their trees, which can counterbalance greenhouse gas emissions into the atmosphere. Study published Friday (17) in the journal Science Advances brings new subsidies to understand the concept of “carbon sequestration”, a strategic aspect in the debate on global climate change.

“We still know little about the factors that can lead forests to store more or less carbon”, says Renato Augusto Ferreira de Lima, a researcher at the Department of Ecology at the Institute of Biosciences at the University of São Paulo (IB-USP), currently at the Center for the Synthesis and Analysis of Biodiversity (Cesab, based in Montpellier, France), and one of the ten scientists who signed the article.

“In this work, we used a large database of forest inventories to assess which factors have the greatest weight to explain current carbon stocks in the Atlantic Forest. We found that factors linked to different types of human impacts on the forest have the weight, which is two to six times greater than factors such as climate, soil and characteristics of the tree species that make up the forest”, he explains.

Therefore, reversing the effects of human impacts on Atlantic Forest remnants would be the best strategy to increase forest carbon stocks. Currently, about 50% of the Brazilian population resides in areas originally occupied by the biome.

According to Marcela Venelli Pyles, a doctoral student in applied ecology at the Department of Ecology and Conservation at the Federal University of Lavras (UFLA), who is leading the study, the conservation of carbon stocks in the Atlantic Forest is highly dependent on forest degradation, which can lead to losses at least 30% higher than any future climate change.

Furthermore, emissions from forest degradation can compromise conservation efforts under climate change mitigation agreements, for example REDD+ targets (an instrument developed under the United Nations Framework Convention on Climate Change to financially reward developing countries for its results related to the recovery and conservation of its forests) and Aichi (20 proposals aimed at reducing the loss of biodiversity approved at the 10th Conference of the Parties to the Convention on Biological Diversity).

For example, the intensification of disturbances within an Atlantic Forest fragment can lead to carbon losses of up to 10.50 tons per hectare, corresponding to the emission of 15.24% of the carbon stored in 1 hectare, while protection can achieve gains of carbon in the amount of 12.02 tons per hectare (+17.44% of storage).

warmer weather

In addition to degradation by human action, the research found how much the Atlantic Forest’s carbon stocks are threatened by climate change, more specifically temperature increase and water stress. If global warming is restricted to 1.5°C above pre-industrial levels, as suggested by the United Nations Intergovernmental Panel on Climate Change (IPCC), 3.53 tonnes per hectare (+5.12%) of carbon would be released only from the Atlantic Forest. “But if global warming continues at its current rate, carbon emissions could exceed 9.03 tonnes per hectare [+13,11% em emissões de carbono]”, adds Pyles.

The article also indicates that initiatives aimed at mitigating climate change through forest restoration could benefit from the inclusion of species with higher wood density, heavier seeds and larger leaves. The group of researchers warns that carbon conservation policies must take into account methodological aspects used to quantify carbon stocks. “Differences between methodologies used in the field can lead to errors in carbon estimation and, consequently, to misinterpretation and inefficiency of climate mitigation actions”, explains Pyles.

The study also points out that the relationship between biodiversity and carbon stocks is weak in the Atlantic Forest. This reveals that conservation policies focused only on carbon can fail to protect biodiversity and highlights the importance of implementing complementary and separate incentive mechanisms that also aim to achieve species conservation.

According to Lima, the results found for the Atlantic Forest can serve as a lesson for other forests in the world – in the face of increasing human interventions in tropical forests around the planet, offering nature-based solutions to combat climate change.

The article is also signed by Luiz Fernando Silva Magnago (Federal University of Southern Bahia), Bruno X. Pinho (Federal University of Pernambuco), Gregory Pitta (USP), André L. De Gasper and Alexander C. Vibrans (Regional University of Blumenau), Vinícius Andrade Maia, Rubens Manoel dos Santos and Eduardo van den Berg (UFLA). The research received support from FAPESP, which financed Lima’s postdoctoral studies.