Perte de masse anhydre et dynamique des elements chimiques du bois rameal fragmente de tremble

Fresh ramial wood chips from aspen (Populus tremuloides Michx.) were applied to the forest floor surface of a recently clear-cut site for a 2-year study of decomposition. Chips enclosed in mesh bags were installed on control and amended treatments (300 or 600 m$\sp3$ ha$\sp{-1}),$ and weight loss and changes in carbon fractions and macro-nutrients were measured during about 2 years. During this period, the substrate lost 38% of its initial mass, was an important source of bases cations, and became a sink for nitrogen (N) and phosphorus. Substrate N dynamics were dominated by immobilization during this 2-year field incubation, however net N release was initiated earlier in the amended treatments than in the control treatments. While the application of ramial chipped wood at the forest floor surface may greatly contribute to the resilience of the ecosystem following harvest, the labor and cost requirements of branch transformation remain a major limitation to such amendment.