A study published Thursday, September 1 in the journal Remote Sensing of Environment reveals that the terrible Australian fires, which destroyed more than eight million hectares of forest between September 2019 and February 2020, ultimately had no impact in terms of CO2 emissions. And this thanks to the vegetation, which by pushing back very quickly after the fires, has reabsorbed almost all of the carbon dioxide released into the atmosphere. A study that allows “draw lessons for the French forest”explains Wednesday, September 7 on franceino Jean-Pierre Wigneron, director of research at the National Institute for Research in Agriculture, Food and the Environment (Inrae) and co-author of the study.
franceinfo: Is this study a good surprise?
Jean-Pierre Wigneron: Yes, even if we expected it a little. We already knew that the Australian forest recovered very quickly after the fire. On the other hand, it is really one of the very first studies which makes it possible to quantify the fact that the recovery in terms of carbon has been total. On the other hand, the same conclusion cannot be drawn for biodiversity.
What is the link between fire and global warming?
Vegetation absorbs carbon to grow, which it captures directly from the atmosphere, which therefore reduces global warming. Conversely, when the forest burns it releases CO2, so the concentration of greenhouse gases increases and reinforces global warming. There is a very strong interaction between vegetation biomass and the impact on global warming.
In Australia, the year following the fires was particularly wet, which favored the regrowth of eucalyptus trees [ces essences sont majoritaires dans les forêts australiennes et connues pour repousser facilement après un feu]. The recovery was rapid and probably allowed this full recovery of carbon stocks.
Is this transposable to the French fires?
No, but we can learn from it. We know for example that the pine forest in the Landes has a very low diversity. It is almost exclusively composed of the same species of maritime pine. Perhaps we should consider diversifying these species and planting trees in the future that are better adapted to fires. In general: the more the forest has a high biodiversity, the more it is resilient to disasters. Including for storms.