Mangroves concentrate highest amounts of CO2 in the Amazon, says research

Translation of Report Posted at 11:50 on June, 2nd 2011 (jc/Recife) VIEW ORIGINAL

RIO - A new research released on Wednesday (1st) by the Brazilian Institute of Geography and Statistics (IBGE) reveals that the highest concentrations of soil carbon in the Amazon are in mangrove areas, currently threatened by changes of preservation rules in the Forest Code, which have already passed by the Chamber. In these locations the concentration of carbon by up to one meter depth reaches 205 tons per hectare. The average for the soil in the Amazon is of 95 t/ha.

The result surprised IBGE technicians, who predicted a higher concentration of carbon in areas covered by dense forests. "It was a surprise", said geographer Rosa Garrido. For her, the study underscores the strategic importance of mangrove conservation and its fundamental role for the climate equilibrium.

It was also found a high concentration of carbon in campinarana areas, a typical vegetation from the upper Negro River. Today, there is no legal protection for campinaranas. The mangroves are classified as Permanent Preservation Areas (PPAs), but they would be completely unprotected if the changes in the Forest Code are allowed. During the presentation of the geo-statistical publication of Natural Resources of the Amazon, the president of IBGE, Eduardo Nunes, said that this study occurred at an "appropriate time".

It is estimated that in 2002, the reference year of the study, there were approximately 48 billion tons of soil carbon and 45 billion tons of carbon in the remaining vegetation in the region. In the specific case of mangroves, which have higher concentrations of carbon, but occupy a relatively small portion of the area, the stock was of 280 million tons in the soil.

"On average, the world emits 10 billion tons of carbon derived from CO₂ per year.", says forester André Almeida. One of the main merits of the study, he says, is the reconstitution of the original stocks (pre-colonization) of the Amazon natural resources. "The stock of carbon that we originally would have in vegetation, of 51 billions of tons, is equivalent to five years of what is being delivered around the world", added André. By 2002, six billions of tons of carbon were removed from that stock by deforestation. In this country, it is estimated that 75% of the CO₂ emissions are derived from changes in land use. According to André, the model used in the study is consistent with the emission inventories of greenhouse gases in Brazil. "The stock of carbon can be transformed into carbon credits. Big money is traded in the international market. And a question remains. What is it worth? What do we have in terms of carbon credits in the Amazon? It is important to keep the forest standing", says Trento Natali Filho, another IBGE technician.

Deforestation

According to the publication, at least 2.6 billion trees have been eliminated from the beginning of the occupation of the Amazon by non-indigenous peoples until 2002. In wood volume, it means 4.7 billion cubic meters. Almost half of that loss (1.2 billion trees) occurred in Pará state, The area deforestated by man's action represents 15.3% of the original vegetation of the biome. The losses of trees are concentrated in the east (Pará, Maranhão and Tocantins) and south (Mato Grosso and Rondônia).

Livestock appears as the main responsible for the alteration of the original soil coverage, representing 51.7% of the deforested area. Secondary vegetation (which arises naturally after the abandonment of deforested areas) accounted for 32.1%, and agriculture, to 15.2%. The Amazon Forest is divided into four formation types: Tropical Rain Forests (Dense and Open), and Seasonal Forests (Deciduous and Semideciduous). The Semidecidual Forests, concentrated in the states of Maranhão and Mato Grosso, the so-called arc of deforestation, were the most proportionately affected: It had changed 27.2% of its original area, which places them in situation of high risk. They occur in only 5.4% of the region.

The IBGE adds that "any program to protect the diversity of Amazonian forests should pay particular attention to the seasonal forests, especially when they are in areas of expanding agrosilvipasture. "In absolute terms, the devastation is concentrated in the Dense Rain Forest: 60% of the removed trees in 2002, the highest concentration was in the Amazonas state (7.4 billion), followed by Pará (5.2 billion) and Mato Grosso (1.7 billion).

By Felipe Werneck (Agência Estado)