Temporal change of tree biomass, productivity, and carbon pool in the dominant forests of Western Himalaya: Insights from repeated vegetation sampling

This research examines the changes in biomass, productivity, and carbon pools within dominant forests (Sal, Chir-pine, Banj-oak and Mixed oak forest) of the Indian Western Himalaya, employing repeated vegetation sampling over a period of 36 year. These forests cover approximate 63 % forest cover of the state. This result revealed that the tree density increased across all stands, with significant gains in basal area except in Mixed-oak forests. Temporal analysis of biomass over 36 years reveals a significant increase in total tree biomass in Sal (26.84 %), Chir-pine (43.80 %), and Banj-oak (4.74 %) forests, while Mixed-oak forests experienced a 21 % decrease. The Net primary productivity (NPP) increased, within by Banj-oak forest (26.42 %) followed by Mixed-oak (15.14 %) and Chir-pine forest (10.97 %). Sal forests exhibited a slight decrease (0.75 %) in NPP. The annual rate of change in NPP has been increased across all forests sites. The Sal and Chir-pine forests showed substantial increases in carbon stock (26.85 % and 43 %, respectively), while Mixed-oak forests saw a decline of 21 %. Carbon sequestration increased in Chir-pine, Banj-oak, and Mixed-oak forests, however, slightly decreased in the Sal forest. These findings highlight complex ecological dynamics, emphasizing the role of forest type in species composition, productivity, and carbon sequestration. The research underscores the significance of ongoing monitoring efforts in comprehending the enduring ecological shifts and their ramifications for strategies in forest management and conservation.