Himalayan Forests Use Dual Approach to Capture and Store More Carbon

A new study in the Garhwal Himalayas shows that how forests store carbon is not uniform—it shifts systematically with altitude and forest composition. As atmospheric CO₂ rises, identifying where natural ecosystems lock away carbon for the long term has become central to climate mitigation planning.

Researchers compared three forest types spanning distinct elevation bands: Deodar forest at higher altitudes, pine forest at mid-elevations, and mixed forest at lower elevations. They quantified carbon in both living biomass and soils, focusing on tree biomass carbon density and soil organic carbon across two soil layers (0–15 cm and 15–30 cm).

The results reveal a clear division of labor. At higher elevations, conifer-dominated Deodar stands accumulated the most carbon in biomass. Their large, long-lived trees create sustained aboveground carbon reservoirs, producing the highest tree biomass carbon density reported in this study.

Mid-elevation pine forests showed comparatively lower biomass carbon density than Deodar forests. Even so, they still contribute meaningfully to regional carbon sequestration, indicating that altitude-driven productivity and stand structure influence how much carbon remains in woody tissues.

Soil carbon patterns told a different story. Lower-elevation mixed forests, dominated by broadleaf species, stored more stable soil organic carbon than the conifer systems. Their soils contained higher very labile and non-labile carbon fractions in topsoil, suggesting faster conversion of plant-derived inputs into forms that resist rapid decomposition.

To connect composition to stabilization, the team evaluated active and passive soil carbon pools. Mixed forests exhibited the largest active and passive pools, consistent with a microbial and chemical environment that favors long-term sequestration.

Overall, the work supports a “portfolio” perspective for Himalayan climate strategies: conifer forests can maximize biomass retention, while mixed broadleaf forests strengthen soil carbon stability. This approach can improve both mitigation potential and ecosystem resilience under changing climate conditions.

The authors also caution that elevation is tightly coupled to microclimate, making it difficult to fully separate forest-type effects from climatic drivers. They recommend expanded temporal monitoring, microbial community analyses, and improved species-specific biomass equations to refine estimates.

For policymakers, the findings argue for altitude-specific forest management rather than one-size-fits-all interventions. Conserving high-biomass Deodar stands and protecting or restoring mixed broadleaf systems could strengthen India’s carbon sink capacity in the Himalayas.