Fires threaten the ability of forests to store CO2

by Kelvin
Fires threaten the ability of forests to store CO2

A survey recently published in the scientific journal Nature Ecology and Evolution indicates that frequent fires threaten ecosystems and the ability of forests to store carbon dioxide. According to the results released, some regions do not recover from fires that occur frequently over the years.

The analysis, led by researcher Adam Pellegrini of the Department of Plant Sciences at Cambridge University, took into account evidence gathered over decades. Through the vast database, the team mapped the damage suffered by regions with annual fires and the changes over 50 years. Among them is an alarming reduction in the number of trees, which reached 72%. In regions with less frequent fires, this number was 63%.

Reduction in CO storagetwo

Record of fires in Brazil in 2020. (News R7/Reproduction)

As a result of this drastic reduction in the green area, there is the reduction in the forest’s carbon storage capacity, mentioned above. In this scenario, the immediate solution is to replant the lost trees. However, Pellegrini warns that some factors must be considered before taking action.

  

Although the wetter regions favor the growth of trees, they are more prone to fire, as are the drier ones. The zones that offer greater safety and resistance, highlights the researcher, are those with moderate temperatures. “Planting trees in areas where trees grow rapidly is widely promoted as a way to mitigate climate change. But, to be sustainable, the plans must consider the possibility of changes in the frequency and intensity of the fire in the long term”, pondered Pellegrini.

Fires reduce soil health

Amazon log on fire.

This is not the first study to address the long-term effects of forest fires. Previous analyzes have revealed that such events reduce the level of nutrients, including nitrogen, in the soil. Although it seems like something negative, the research published in the magazine Nature Ecology and Evolution points out that this may favor slower-growing trees, which are able to survive in poor soils.

However, these trees make the recovery of forests more difficult, as they retain nutrients, preventing the soil from enriching and allowing the growth of new seedlings after an intense fire.

Increased carbon in the atmosphere

Top view of part of the burnings in the Amazon.

Along with the increasing degradation of ecosystems, researchers have recorded an increase in the amount of carbon dioxide in the atmosphere, driven by fires that destroy 5% of the Earth’s surface each year, releasing COtwo equivalent to 20% of annual fossil fuel emissions.

This is a relatively new problem. In the past, most of the gas released by fires was recaptured once ecosystems were recovered. However, with the intensification of climate change, events became less spaced. As an example, we cite the Brazilian scenario in 2020, which had the highest number of burns in the decade, according to data from the National Institute for Space Research (Inpe).

“The most fire-tolerant tree species generally grow slower, reducing forest productivity. As climate change causes forest fires to become more intense and droughts more severe, the recovery capacity of forests is impaired, reducing their capacity to store carbon”, explains the researcher.

The study, which is funded by the US National Institute of Food and Agriculture and the Gordon and Betty More Foundation, is the broadest of its kind, with data from 29 sites in different ecosystems spanning Africa, Australia, Europe and North America. North.