Ecological divergence in the silver moss Bryum argenteum: developmental, ontogenetic and life-history trait variations across contrasting tropical ecosystems

This study investigates the reproductive and vegetative development of Bryum argenteum in two contrasting tropical environments: the Seasonal Tropical Dry Forest (SDTF) and the Brazilian Atlantic Forest (BAF). By comparing ecotypes from these regions, we aimed to understand how environmental variation influences sex-specific traits, reproductive strategies and potential trade-offs between sexual and asexual reproduction. We conducted temporal analyses of protonema growth, shoot production, sex expression, bulbil formation and gametangia development in laboratory-grown samples representing male and female ecotypes from both environments. Significant differences were found between ecotypes and sexes. Male BAF ecotypes showed lower protonema growth and delayed shoot production compared to other groups. SDTF males exhibited the highest sex expression at Week 8. A negative relationship between sex expression and bulbil production was detected only in SDTF males. Gametangia development also varied, with male BAF ecotypes requiring more time to initiate sexual expression and mature phases revealing further distinctions. The observed differences across ecotypes and sexes reflect adaptive strategies shaped by the ecological conditions of each habitat. In particular, the delayed or reduced reproductive investment in male BAF ecotypes and the trade-offs in females suggest context-dependent allocation of resources. These patterns highlight the complex interplay between environment, sex and reproductive timing in tropical mosses.