Mosaic forest silviculture

A mosaic forest is a stand made up of several species, often of different ages, planted or regenerated together. The goal is resilience: when drought, pests, or disease hit one species, the others continue to provide cover, soil protection, and economic value. It is the explicit alternative to the productivity-driven monoculture model that left European forests so exposed to bark beetles after 2018. The ONF (Office National des Forêts) promotes this concept across all French public forests as part of its climate adaptation strategy. In practice it means mixing oaks, cedars, hornbeams, lindens, and other candidate species into formerly pure beech, spruce, or fir stands, and accepting that the new forest will look and behave differently from the one it replaces. Mosaic silviculture is being applied opportunistically wherever clearings or replantings occur, but it cannot be retrofitted onto existing stands at scale — only the next generation of trees benefits. Foresters across the Grand Est use it where they can, and it is now embedded in management plans for communal forests.