Reforestation is the practice of replanting or naturally regenerating trees in areas where forests have been cut down or degraded. It is a type of forestation employed in areas that have been affected by natural disasters such as wildfires or droughts, as well as man-made disturbances like logging, mining, and agricultural clearing.

There are two primary types of reforestation:

• Urban reforestation: The planting of trees in urban environments. Urban reforestation is typically used to increase shady areas, protect against heat, improve air quality through CO₂ capture, and transform the urban landscape.
• Rural reforestation: The large-scale planting of trees to restore deforested areas. Rural reforestation can have a variety of aims, including preserving species native to the area, fertilising the soil, protecting the area against erosion, and recovering forested areas destroyed by natural disaster.

By replanting trees where forests once stood, reforestation helps to heal damaged ecosystems and supports climate goals. It takes thoughtful planning and management to ensure the success and sustainability of these new forests.

Many countries and organisations are committing to large-scale reforestation efforts.

Alongside the primary benefit of helping to offset emissions and mitigate climate change, reforestation efforts offer a wide range of co-benefits. However, reforestation also comes with certain challenges that are important to consider.

Co-benefits of reforestation

Reforestation offers both environmental, economic, and social co-benefits, including:

• Biodiversity restoration: Replanting native tree species creates habitats for wildlife and restores ecosystems that support a wide range of plant and animal species.
• Soil protection: By stabilising the ground with their roots, trees help prevent soil erosion. This is particularly important in areas prone to landslides or desertification.
• Water cycle regulation: Trees help filter water, reduce runoff, and maintain groundwater levels, making forests crucial for maintaining local and global water cycles.
• Sustainable resources: Because forests provide timber, non-timber products, and other resources that can be sustainably harvested, reforestation can contribute to livelihoods in rural areas.
• Job creation: Reforestation projects often create jobs in planting, forest management, and conservation activities, benefiting local economies.
• Community well-being: Healthy forests improve the overall life quality of their surrounding communities by contributing to clean air and water and providing spaces for recreation and cultural activities.

Challenges of reforestation

The challenges surrounding reforestation projects include:

• Tree species selection: Non-native or monoculture plantations can lead to poor ecological outcomes, making it important to choose the right species of trees for the specific environment.
• Maintenance: Until they are properly established, newly planted trees require care and protection from threats such as pests, fire, and logging.
• Land use conflicts: In some areas, reforestation projects may conflict with agricultural, industrial, or residential land uses. This makes it important to balance local communities, land users, and land owners. 

These challenges emphasise the importance of ensuring that reforestation projects are planned carefully to contribute towards combating climate change.

It should also be noted that older trees generally sequester more carbon per year than younger trees. This means that avoiding deforestation is just as important for reaching our climate goals as replanting degraded forests or planting new ones.

Reforestation vs afforestation: What is the difference?

The term reforestation is often confused with ‘afforestation’. Both reforestation and afforestation contribute to increasing forest cover and can therefore benefit climate goals, but take place in different ecological contexts which affect the strategies used and the potential outcomes for the ecosystems involved.

• ‍Reforestation involves planting trees in areas where forests previously existed, but were removed or degraded due to activities such as logging, agriculture, wildfires, or urbanisation. These areas typically still have soil conditions, microclimates, and remnants of the previous forest ecosystem that support regrowth.‍
• Afforestation is the practice of planting trees in areas that were not previously forested, such as grasslands, savannas, deserts, or former agricultural land. These areas may have been naturally unforested for centuries or millennia due to climate, soil conditions, or natural ecosystems.

Both reforestation and afforestation are valuable strategies for combating climate change. However, their ecological outcomes are context dependent. Reforestation tends to be more ecologically beneficial in restoring degraded forests, while afforestation requires more careful planning to avoid negative impacts on the existing environment.

Overall, by helping to restore biodiversity, preventing soil erosion, and providing resources to local communities, reforestation is a crucial resource on the road towards net zero.