The objective of this study was to investigate the impact of forest fires on tree diversity and their regeneration in three fire-prone forests of Uttarakhand, India. We used Landsat 5, 7, and 8 satellite imagery to prepare fire frequency maps and the study area was divided into four fire frequency classes. Ten plots were marked in each fire frequency class to assess diversity and regeneration pattern of tree species. A total of 14 tree species belonging to 14 genera and 13 families were sampled during the study period. We found that tree species diversity was higher in areas with low fire frequencies in comparison to the areas with no fire frequency class. We also observed that regeneration of tree species varied significantly across all fire frequency classes and forest types, with increasing dominance of certain fire-tolerant species in areas with frequent fires. Of the 33,678 individuals (tree, sapling, and seedling) recorded in all the fire frequency classes, 12,630 were in Sal Forest, 8,033 were in Chir-pine Forest, and 13,015 were in Mixed Forest. The study suggests that if forest fire incidences continue at current levels, the forests could experience a decline in tree diversity. Although forest fire is a natural occurrence in many ecosystems, the increasing frequency and intensity of fires due to human activities such as land-use change and climate change have disrupted the natural fire regime.

Unprecedented seasonal forest fires pose a significant threat to the carbon stocks of diverse ecosystems, particularly in regions like Uttarakhand, west Himalaya. Understanding the impact of varying fire frequencies on different forest types is crucial for effective conservation and management strategies. This study aims to assess the loss of carbon stock in three distinct forest types—Sal, Pine, and Mixed across an elevation gradient in Uttarakhand, facing unprecedented seasonal forest fires. By investigating pre- and post-fire conditions, analyzing biomass dynamics, and mapping fire frequencies, the research aims to provide insights into the complex interplay of fire regimes and forest resilience. The investigation covers vegetation analysis, biomass assessment, and fire frequency mapping. Biomass and carbon stock calculations were carried out using a non-destructive sampling method. Fire frequency maps were generated using Landsat satellite imagery spanning a decade, integrating MODIS hotspot data for classification. The study reveals distinct patterns in biomass changes across Sal, Pine, and Mixed forests in response to varying fire frequencies. Sal forests exhibit resilience to low-intensity fires, while Pine forests show higher sensitivity. Carbon stock contributions of dominant species varied significantly, with Sal and Chir-Pine forests emerging as crucial contributors. High fire frequencies lead to substantial carbon stock reduction in all forest types. The findings emphasize the sensitivity of aboveground biomass to fire frequency, with significant carbon stock loss observed in higher fire frequency classes. The study underscores the importance of nuanced conservation strategies tailored to distinct forest types and species characteristics. This research provides valuable insights for policymakers, forest managers, and conservationists in formulating targeted conservation and management approaches.