Why in news?
Environmental debates in August 2025 compared the carbon‑sequestering roles of younger forests and old‑growth forests. This discussion is important as countries pledge large‑scale tree planting while also confronting the loss of ancient forests.
Characteristics of younger forests
- Rapid growth: Trees under forty years grow quickly and absorb carbon dioxide at high rates because they are building trunks and leaves.
- Less biomass: Despite their speed, these forests store less total carbon because the trees have not yet accumulated large trunks and soils remain shallow.
- Vulnerability: Young plantations are more susceptible to pests, fires and storms. Monocultures provide limited habitat for wildlife.
Characteristics of older forests
- Massive carbon stores: Trees over a hundred years hold huge amounts of carbon in their wood and soils. Even though net annual growth is slower, they serve as long‑term reservoirs.
- Rich biodiversity: Old‑growth forests support complex webs of plants, fungi, insects, birds and mammals. Their layered canopies and rotting logs offer niches that younger stands lack.
- Stable hydrology: Mature root systems regulate groundwater, maintain soil moisture and reduce flood peaks.
Implications for policy
Both types of forests are valuable. Restoring degraded land with fast‑growing species can quickly remove carbon from the atmosphere, but protecting existing old‑growth forests prevents the release of centuries of stored carbon and preserves biodiversity. Afforestation efforts should prioritise native species and allow mixed‑age stands to develop. Sustainable forestry must combine planting with conservation.