Survival Strategies of Specialists and Generalists in Maintaining Ecological Networks of the eastern Himalayan river basin

Microeukaryote generalists and specialists are vital for community dynamics and ecosystem functioning, but their distribution patterns, assembly mechanisms, and mutual transformation are poorly studied in the extreme Tibetan Plateau environment. This investigation examines diversity patterns, community assembly, species interactions, and evolutionary dynamics of microeukaryotic communities, including subcommunities (of generalists and specialists, across seasonal gradients in the eastern Himalayan river basin. Generalist and specialist subcommunities exhibited distinct seasonal distribution patterns and ecological functions. Contrary to predictions, specialists had higher abundance and richness in both seasons. Diversity indices (Shannon, Simpson, richness) were elevated in dry season, while phylogenetic diversity fluctuated. β-diversity was primarily driven by species replacement, with specialists showing higher turnover. Community assembly became more stochastic from dry to wet season, especially for specialists, whereas deterministic forces dominated for generalists. Geographic factors, particularly latitudinal gradients, were key drivers of seasonal composition differences. Co-occurrence networks revealed that while both subcommunities are crucial for stability, specialists were disproportionately responsible for complexity and robustness. These findings expand understanding of specialists’ and generalists’ survival strategies in ecological networks. Specialists create intricate, fragile networks and drive microeukaryotic diversification by transforming into generalists. This distinct mechanism in plateau river ecosystems highlights specialists’ pivotal role in maintaining ecosystem stability and resilience amid harsh environments.