Impact Of Natural And Anthropogenic Disturbances On The Microbial Diversity In The Critical Zone Of Pranmati Basin In North-West Himalaya, Uttarakhand

Abstract

Bacterial community, an indispensable component of the soil in the critical zones, plays a significant role in maintaining soil health and ecological balance. This study focuses on assessing soil health by utilizing the bacterial diversity and enzymatic activity of the bacterial community in natural environments such as forest land, disturbed environments like flood zone land, and human-managed environments like agricultural fields in the unexplored Himalayan region. The activity of acid phosphatase and β-glucosidase was consistently high in soils from all landforms, the highest being in slightly acidic (pH 6.39 - 6.87) forest soil. Actinobacteriota was the dominant phylum in agriculture (28.97%) and flood zone lands (34.37%), whereas Proteobacteria (29.44%) was predominant in forest land. The beta diversity analysis indicated similarity in the species composition of forest and agricultural land, while differential abundance analysis showed maximum species abundance in forest land. Phylogenetic studies based on 16S rRNA sequences revealed lipopolysaccharide biosynthesis as a major metabolic function among all land covers. Principal component analysis shows that forest soil and agricultural soil are connected in terms of abiotic and biotic parameters. However, these parameters are not the same in flood zone soil, even though the soil is physically connected. The present work provides valuable insights into soil health and environmental management in different natural and human-managed settings by understanding how the native bacteria interact and function with respect to their surroundings, aiding landscape restoration and terrestrial ecosystem functioning of the Pranmati Basin, a critical zone in the Himalayas, Uttarakhand.