Ecological Restoration

Ecological restoration is the process of assisting the recovery of a degraded ecosystem so that its biodiversity, ecological functions and capacity for self-renewal are restored. Tree plantation is the deliberate establishment of trees; it may increase tree cover but does not by itself recreate a functioning forest ecosystem.

Difference in objective and scope

A forest is more than a collection of trees. Restoration addresses the ecosystem as a whole, whereas plantation primarily concerns the establishment and survival of planted trees.

• Restoration seeks recovery of native species composition, vegetation structure, soil processes, water regulation and wildlife habitat.
• Plantations may be single-species, even-aged and production-oriented; therefore, higher tree density alone is not evidence of ecological recovery.
• Restoration aims to rebuild resilience so that the ecosystem can persist and regenerate with progressively less human assistance.

How degraded forests are restored

Restoration begins by identifying and reducing the drivers of degradation. The appropriate method depends on the site's ecological condition, past land use and remaining sources of natural regeneration.

• Protection from repeated fire, excessive grazing, felling and other pressures may permit natural regeneration from surviving trees, seed banks and nearby forests.
• Active measures can include controlling invasive species, conserving soil and moisture, restoring drainage, and reintroducing locally suitable native species.
• Where natural recovery is inadequate, assisted natural regeneration or mixed native planting may accelerate recovery.
• Progress is assessed through survival and regeneration as well as biodiversity, soil condition, habitat complexity and ecosystem functions.

Role and limits of tree plantation

Planting is one possible tool within restoration, not a substitute for it. Its ecological value depends on species choice, site suitability, diversity, spatial design and subsequent management.

• Mixed plantations of locally appropriate native species can help restore severely degraded sites where seed sources are absent.
• Monocultures or unsuitable exotic species may provide timber, biomass or rapid canopy cover without restoring the original forest community.
• Planting trees in naturally non-forest ecosystems can damage their characteristic biodiversity; restoration must respect the appropriate ecosystem type.