Un article vient de paraître dans la revue « Science of The Total Environment » sur l’importance de différents facteurs sur les stocks de carbone et d’azote en forêts composées de chêne sessile et de pin sylvestre. L’importance de l’identité de l’espèce d’arbre, de la composition du peuplement et du sous-étage sur ces stocks ont été évalués:
Korboulewsky, N., Javoy, T., Pérot, T., Ouimet, R., 2025. Importance of species identity, species mixing and understory on carbon and nitrogen stocks in sessile oak and Scots pine stands. Science of The Total Environment 1000, 180410. https://doi.org/10.1016/j.scitotenv.2025.180410
Les points forts :
- L’identité de l’espèce d’arbre a un effet plus fort sur les stocks d’azote et de carbone que la composition du peuplement ;
- L’effet de la composition du peuplement est limité ;
- Le sous-étage contribue entre 29 et 49% aux stocks d’azote et de carbone contenus dans la végétation ;
- La biomasse racinaire est la principale source d’incertitude dans l’estimation des stocks ;
- Le principal défi pour les gestionnaires est de maintenir les stocks plutôt que de les augmenter.
Résumé :
Forests contribute the most to the carbon stocks of the terrestrial biosphere. Estimates are available at different scales, though a large degree of uncertainty remains. In particular, the understory is seldom taken into account. In this study, we measured the carbon and nitrogen stocks of all ecosystem compartments, including trees, understory, deadwood, and soil, in pure sessile oak, pure Scots pine and mixed stands of the two species. We studied the importance of different compartment stocks and the effects of stand composition. We also evaluated different sources of uncertainty related to the calculation parameters of the estimates.
We found that species identity affected ecosystem C and N stocks more than stand composition did. The effects were primarily observed in the forest floor (mainly the organic layer) and the understory. No stand composition effects were observed for either soil C stability or C and N stocks in the mineral horizons, indicating that physicochemical processes dominate. Our results show that the understory can account for more than a quarter of vegetation C stocks and up to one-half of vegetation N stocks in pine low density stands. This importance of the understory was most significant in low-density pure pine stands. The root biomass of the trees and understory vegetation were the primary sources of uncertainty in stock estimations
Résumé graphique :
