Current state
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The mean growing-stock volume of the French forests is estimated at 2.9 billion cubic meters. [1]
This volume calculated by the French National Forest Inventory (NFI) represents the stem volume of live trees with a diameter at breast height greater than 7.5 cm, from the stump to a minimum top diameter of 7 cm over bark.
The growing-stock volume per hectare is 173 m³. |
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| Definition of the growing stock. |
For more information, see the article "More than 190 tree species inventoried in France"
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Broadleaves (hardwoods) account for almost 2/3 of the growing stock, which represents 1.9 billion m3. Oaks (including pedunculate, sessile, pubescent and evergreen oaks) make up more than a quarter (29%) of the total growing-stock and 44% of the hardwoods’ growing stock. Beech accounts for 10% of the total growing stock. Conifers (softwoods) account for 1 billion cubic meter. Norway spruce accounts for 6% of the growing stock and silver fir for 8%. Together, Norway spruce and silver fir represent 40% of the softwoods in terms of growing stock. |
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For broadleaves, trees with a diameter below 37.5 cm account for more than 50% of the growing stock volume. For conifers, 80% of the volume is composed of trees with diameters between 17.5 and 57.5 cm.
Growing-stock volume, depending on diameter classes and leaf type [2]. |
Evolution of the growing stock
Over the past 4 decades, a significant increase in growing stock has been observed, rising from 1.8 billion m3 in 1985 [3] to 2.9 billion m3 today, which represents a 50% increase.
This increase amounts to more than 1 billion m3, which corresponds to the current growing stock in the Grand Est, Bourgogne-Franche-Comté and Centre-Val de Loire regions combined.
During this period, the growing stock per hectare increased from 137 m3/ha to 173 m3/ha. Meanwhile, the number of trees per hectare slightly decreased. Stands are producing more because of larger and/or taller trees.
The increase in growing stock is higher for hardwoods (+67%, +750 Mm3) compared to softwoods (+41%, +290 Mm3).
Evolution of the growing stock of living trees between 1985 and 2024. |
Deadwood
In addition to measurements from live trees, data are also collected from standing and fallen deadwood. In 2024, the volume of standing deadwood represents 159 million m3, or 5% of the volume of all (live and dead) standing trees. Fallen deadwood accounts for 300 million m3. On average, one hectare of forest area contains 10 m3 of standing deadwood and 18 m3 of fallen deadwood.
