Restoration of degraded ecosystems in the Normandie-Maine Natural Regional Park by application of an alkaline amendment. An appraisal five years onwards.

摘要

Four experimental systems were set up in the Sarthe and Orne forests in partnership with the Normandie-Maine Natural Regional Park for the purpose of studying the effect of alkaline amendments on natural or artificial regeneration, on the development of humus forms and on the nutrient status of the acidic forest soils in western France. Five years after application, some improvements are observed: better nutrition of existing trees (both seed trees and seedlings), changes in vegetation that reflect improved biological activity (drop in C/N ratio), increased pH and soil saturation rate, sharp increase in stored nutrients. However, these enhancements are concentrated in the area were the amendment was applied and did not penetrate deeply. Conversely, there was no significant change in the volume of litter or the morphology of humus forms. This is in sharp contrast with the findings in the forests of eastern France. A caveat however: beneficial effects on forest soils materialize very slowly and a 5-year observation period is certainly too short.