Seasonal shifts in vegetation, soil properties, and microbial communities in Western Himalyan forests

Background and aims The Western Himalayan Forest ecosystem faces unprecedented pressure of climate change and anthropogenic activities. To enhance the resilience of high-altitude forests, improved conservation and management programs are a key. For the programs to be effective, knowledge on the seasonal effects on vegetation, soil properties and microbial communities in high altitude forests is needed, but this information is uncertain across high altitude forest types. Methods To fill the gap, we examined the seasonal variation in vegetation, soil and microbial communities by determining vegetation diversity indices, soil properties, soil metagenomic analysis across 10 distinct forest types during winter, 2023, and summer, 2024 respectively. Results Summer showed greater species richness ( p  < 0.001), Shannon ( p  < 0.001), and Simpson diversity ( p  < 0.008), while winter had greater evenness ( p  < 0.005) and community maturity ( p  < 0.02). Soil pH was 2–3% greater ( p  < 0.05) in summer (winter:6.04–7.5; summer:5.9–7.9), with 125–130% greater ( p  < 0.05) microbial biomass carbon (MBC) but 30–35% lesser ( p  < 0.05) soil moisture and 20–25% lesser ( p  < 0.05) soil organic carbon (SOC). Microbial α-diversity was greater in summer (Shannon: p  < 0.006; richness: p  < 0.006) while functional profile was stable ( p  > 0.05). Beta diversity showed high dissimilarity in conifers (0.509) versus MWB (Mix Mekha Wali Burmi Forest, Surgan) and OQMF ( Olea and Quercus Mix Forest, Baandi) (0.035). Conclusions Structural Equation Modelling (SEM) showed stronger summer plant-soil-microbe linkages (summer R²=0.78 vs winter 0.71), demonstrating microbial resilience and the need for seasonal forest management.