Climate and plant traits alter the relationship between seed dispersal and seed dormancy in alpine environment

Species employ seed dispersal and dormancy to mitigate competition and extinction risks in uncertain environments. Theoretical insights suggest a trade-off in that efficiently dispersed species tend to exhibit lower seed dormancy. This trade-off is hypothesized to be modified by life history traits and climatic factors. We collected data from 543 species, encompassing dormancy, dispersal capacities, climatic conditions (temperature and wind speed), plant height, seed mass, and shape from the Tibetan Plateau. We found that larger, non-spherical seeds favor strong dispersal and non-dormancy. Woody species demonstrate greater dispersal and lower dormancy compared to herbaceous species. A no-significant negative association between dispersal and dormancy was found, but the significance and magnitude of the trade-off depended on plant traits and climate. This trade-off amplifies with higher temperatures and non-spherical seed shapes. The trade-off strengthens as seed mass, plant height, and wind speed decrease in woody plants, but not in herbaceous plant. The interplay between climate factors and life-history traits affects the trade-off dynamics. Our results suggest that plants may not invest in a single dispersal or dormancy strategy to adapt to cold alpine environments. Distribution of species (herbaceous and woody), and plasticity of plant height, and seed traits are determined by environment and climate, which may limit the expression of dispersal or dormancy strategies. If dormancy is necessary under an altered climate, certain species that lack dormancy plasticity may face the risk of extinction, and thereby alter species coexistence status and community structure of alpine vegetation.