From flames to recovery: ecosystem resilience in Uttarakhand’s 2022 forest fires

Abstract

Foothills of the Himalaya are one of the major hotspots of forest fire in India. Forest fire in the hot-dry summer season (March-June) often causes significant damage to the Himalayan Forest ecosystem – one of such caused in Uttarakhand state of India in 2022. Despite the 2022 forest fire heavily destroyed the natural vegetation and caused significant economic losses, it’s drivers, impact on vegetation, and vegetation resilience are not well understood. Using several hydroclimatic, vegetation, and fire datasets, we thoroughly examined the spatial and temporal variation of burnt vegetation and its recovery during the 2022 forest fire in Uttarakhand. Differential normalized burnt ratio (dNBR) indicated that high-severity burns were concentrated in the southern regions of Uttarakhand, with widespread moderate to low-severity areas (early stages of regrowth). The fire caused a 16.75% loss in biomass, followed by a 40.85% post-fire recovery, resulting in a net 14.35% gain, highlighting strong but uneven ecosystem resilience. Extreme heat and dryness from February to June, marked by high VPD and low soil moisture, intensified fire risk across Uttarakhand. Monsoon onset and possible fire-induced rainfall helped restore soil moisture and reduce VPD, supporting early vegetation recovery. The satellite observation indices observed dynamic restoration immediately after the fire event, showing SAVI (~0.23 – 0.43) and VCI (~40 - 80), indicating secondary succession. Later, during the monsoon season, the greenness gradually restored was identified over different vegetation indices. Moreover, this variation was also evidently observed in the carbon pools. The long-term assessment was performed using GPP and ET, which are crucial for vegetation restoration. This study highlights the importance of assessing and understanding the vegetation dynamics. Providing key insights into the supporting atmospheric conditions and internal characteristics of vegetation recovery offers guidance for adapting to forest fire impacts.