According to IGN, the National Institute of Geographic and Forestry Information, the “forest watchdog”, it covers 17.5 million hectares, or one-third of the metropolitan area: it’s growing, but its condition is affecting its character. It is getting worse. As a green lung.
Tree mortality increased from 7.4 million cubic meters per year to 15.2 mm between 2005 and 2013.3 For the period 2014-2022, 0.5% VolumeVolume Total trees in the forest are due to increasingly unfavorable conditions for trees, which favor the proliferation of “bioaggressors” (fungi, insects, BacteriaBacteria). Added to this is “water stress”: “lack of water” or, conversely, “too much water, as it is now”, of the inventory servicing service during a press conference at IGN headquarters. Chief Stephanie Verplot emphasized that. In St. Mandy’s
Reduced tree growth and reduced CO2 absorption
Published annually based on data collected over the past five years, the inventory shows a 4% reduction in tree growth (between 2005-2013 and 2014-2022) and therefore also a reduction in their CO absorption. has been noted.2.
Metropolitan forests absorbed 39 million tons of CO.2 An average of 63 per year in the 2014-2022 period, according to the inventory, compared to 63 in the 2005-2013 period.
Evolution of carbon stocks in forests
Despite this slowdown, CO’s stock2 That which is in, and thus out of, the atmosphere increased by 17% between 2009 and 2023. The 11.3 billion trees calculated by IGN in 2023 represent a reserve of 1.3 billion tons. CarbonCarbon.
” Today, each hectare of forest holds an average of 81 tons of carbon in its living trees. compared to an average of 73 in 2009, according to IGN. The increase in function is actually very old and can be explained by forest densification in recent decades. According to IGN, in 1981 the average was 58 tons of carbon per hectare.
According to data published in May by IGN and FCBA Technological Institute, the potential ofAbsorptionAbsorption Within a decade, the forests have been reduced to half. And a projection for 2050 estimates that “ In the majority of (…)) Scenarios “Study,” Carbon sequestration in forests continues during the 2020-2050 projection period ».
A disturbing projection for the coming years
gave get tiredget tiredan organization obliged to carry out the French inventory. BroadcastingBroadcasting For its part, an average decline in storage of “2.1% per year” between 2019 and 2022 is noted. According to a forecast from the National Low Carbon Strategy, a trend that will accelerate with a reduction of -4% annually between 2029 and 2033.
Last month, experts at the High Council ClimateClimate (HCC) were concerned about the low absorption of CO.2 In natural sinks, such as forests, after France, which is intended. Carbon neutralityCarbon neutrality by 2050, has failed to meet its 2019-2023 climate targets, mainly due to lower-than-expected absorption by forests and soils.
By counting the carbon in dead trees and The matterThe matter The total organic, forest ecosystem stocks in topsoil are estimated at 2.8 billion tons of carbon according to IGN.
New indicators for measuring forest health
The institute also introduced a new indicator, called “Deperis”, which aimed to measure the health status of trees by taking into account the presence of dead branches in the upper part of trees. According to this indicator, 8% of forest trees are replaced.
Another indicator is to gather the presence of large ungulates – deer, antelope and other bighorn sheep – which can damage trees by grazing on trunks or bark or by rubbing against each other. Such marks are present on 29% of young trees.