Research shows that macaúba plants aged between 1.6 and 9 years have the potential to sequester 28.73 tons of CO2 per hectare annually.

The consequences of climate change are becoming more apparent with each passing year. In December 2021, more than 20 tornadoes swept through six states in the Southeast and Midwest regions of the US outside the traditional tornado season. In Brazil, in the same month, an extra-tropical cyclone caused heavy rains and flooding in the South of Bahia and North of Minas Gerais. For Brazilians, 2021 was a year of weather extremes: many regions recorded prolonged periods of drought followed by frosts, which led to a sharp rise in the price of food.

According to the most recent report by the UN’s Intergovernmental Panel on Climate Change (IPCC), events such as these will become increasingly more frequent. The temperature of the planet has already risen by 1.2°C and the forecast is for a continued rise of at least 1.5°C over the next 20 years, unless there is a drastic reduction in greenhouse gas (GHG) emissions.

Within this context, the macaúba - a palm tree native to the tropical regions of the American continent - seems to be a promising species, providing, as it does, a range of ecosystemic services. But this is not just a promise, but the subject of scientific research explored in the article “Above-and below-ground carbon accumulation in cultivated macauba palm and potential to generate carbon credits” published in the “Journal of Cleaner Production” and authored by the researchers: Sandro Lucio Silva Moreira, Hewlley Maria Acioli Imbuzeiro, Colby Silvert, Otto Herbert Schuhmacher Dietrich, Leonardo Duarte Pimentel and Raphael Bragança Alves Fernandes. 

Hewlley is one of the researchers. She is a professor with the Department of Agricultural Engineering at the Federal University of Viçosa (UFV) and leader of a micro-meteorology research group (MICROMET) “When I created the MICROMET group, I wasn’t too excited about focusing the studies on more traditional farming (soy, corn, sorghum, etc.), because many of my colleagues had researched these crops for a long time within the area of applied meteorology. So I started reading what had been published in Brazil about the native crops and the macaúba really stood out,” she says.

She started researching the effects of the macaúba on the use of the earth, on the environmental aspects (carbon sequestering) and in relation to the mitigation of climate change. This palm tree attracted Hewlley’s attention because it was a source of raw material for the production of oils and bioenergy. In the study that was the subject of the abovementioned article, the group of researchers of which the professor is a member studied the macaúba’s potential for carbon sequestering, since through until then nothing had yet been published on the subject.

The group’s studies involved measurement of the accumulation of carbon in the biomass (above and below-ground) of macaúba palms of different ages being farmed commercially. According to the article’s abstract, “the samples were fully harvested by complete removal (including roots and above ground structures), followed by separation, quantification and carbon analysis of the different plant biomass components”. 

With the data obtained, the group estimated the carbon credits and the resulting annual yield. The expected generation of carbon credits of palms from 1.6 to 9 years was 28.73 t CO2eq. ha−1 per year, which could result in an annual gross income of € 761.06 per hectare.  Significant amounts of stored carbon were found in both the above and below-ground biomass, suggesting that the macauba has significant potential to generate carbon credits and contribute to the mitigation of the effects of climate change,” stated the article.

And the studies continue. The MICROMET group is directing its studies of the macaúba towards obtaining the information and the parameters necessary for developing a robust model for a simulation of the interaction between the earth, the macaúba and the atmosphere. “We are currently using the model to price the carbon sequestering for the farming of macaúba in damaged areas in Brazil and starting field experiments to find a model that touches on aspects of the water cycle within macaúba crops, such as evapotranspiration, interception of rainwater by the canopy, infiltration of water into the earth, surface drainage, etc.”, explains Hewlley.

According to the scientist, considering the forecasts established in the IPCC’s most recent reports, the macaúba could be an important alternative for the global plant oils market due to its low hydro-related demands, or, in other words, it needs less water when compared to the world’s leading and most productive oleaginous species, the African palm. “In the Brazilian Southeastern and Central Western regions, the species is found in nature in regions with an average annual rainfall of around 700 to 1,880 mm, which confirms its suitability to the Brazilian Cerrado and means it can be planted in damaged areas and, within the present scenario of climate change, it is more resilient, or in other words, it is more resistant to periods of water shortage or wildfires,” summarizes Hewlley.

Fonte: S.OLEUM