Climate warming reshapes seasonal flowering but stabilizes species interactions in a Tibetan alpine grassland.

Climate warming commonly drives asymmetric shifts in flowering phenology among species, potentially disrupting plant-plant interactions and threatening ecosystem stability. However, the mechanisms driving these species-specific phenological responses, and the extent to which resulting asynchrony destabilizes interspecific interactions, remain poorly understood. Using a 3-yr in situ warming experiment in a Tibetan alpine grassland, we monitored seasonal flowering patterns of 29 species and quantified interaction potentials across 812 species pairs from their flowering-time overlap. Warming advanced the start of the flowering season in 75.9% of species and the end of the flowering season in 69.0%, with greater phenological shifts in late- than early-flowering species, in insect- than wind-pollinated species, and with more similar shifts in closely related species than in distantly related species. By contrast, warming significantly altered the interaction potential in only 6.8% of species pairs (55/812), independent of the pairwise phylogenetic distance. Our results advance understanding of species-specific phenological shifts in alpine grasslands and reveal that warming may induce substantial phenological reassembly without necessarily disrupting plant-plant interactions, suggesting resilience of ecological networks to phenological change.