Elevational Filtering Drives Pollinator Community Disassembly in the Mountain Orchards of Doda, Indian Himalayas

Pollinators are indispensable for the productivity of temperate fruit crops like apple and apricot, yet their diversity and drivers remain critically understudied in the complex topography of the Himalayan region. This study presents the first comprehensive assessment of pollinator communities in the agroecosystems of Doda District, Jammu and Kashmir, India, a region of global agricultural significance. We sampled insect pollinators across a steep elevational gradient (1073–2302 m ASL) in six orchard sites during the 2024 bloom period. Using standardized protocols of pan trapping and timed observations, we documented species composition, abundance, and diversity. The impact of abiotic factors (elevation, temperature) was analyzed using Pearson correlation, linear regression, and multivariate statistics (NMDS, PERMANOVA). We recorded 662 individuals from 14 species across 10 families. A dramatic decline in pollinator diversity and abundance was observed with increasing elevation: total abundance fell by 75.7% and species richness dropped from 9 to 3 species. Elevation alone explained a remarkable 94.7% of the variance in Shannon diversity (H' = 3.12–0.00095 × Elevation; R² = 0.947, p < 0.001). Multivariate analysis revealed a significant compositional shift (PERMANOVA: Pseudo-F = 8.91, p = 0.002), driven by a major taxonomic restructuring: the relative abundance of Halictidae increased from 19.8% at low elevations to 41.5% at high elevations, effectively replacing Apidae as the dominant family. Furthermore, a fine-scale comparison at a single site showed significant partitioning between crops, with apple attracting more Apidae (46.8% of visits) and apricot attracting more Syrphidae (44.7% of visits). This study establishes that elevation acts as a master environmental filter, overwhelming local factors to structure pollinator communities in Himalayan orchards. The documented patterns and the unique baseline data provide critical insights for crafting elevation-specific conservation strategies to safeguard pollination services and the resilience of mountain agriculture in a warming climate.