ABSTRACT

Species variation in relation to habitat differences may offer valuable insights into understanding population divergence and speciation itself. In central Amazonia, phenotypic and phenological variation of four bryophytes - Octoblepharum albidum, Octoblepharum pulvinatum, Leucobryum martianum and Pilosium chlorophyllum - were investigated among white-sands and terra-firme plateaus to examine whether habitat differences relate to trait variation. In three of the four species, sexual expression was significantly more restricted temporally in the drier habitat type (white-sands forest) than that observed in more mesic, terra-firme plateau forests. Contrary to global patterns of reproductive behavior for bryophytes, male expression was notably more prevalent than female expression for three of the four species. Furthermore, significant infra-specific phenotypic variation among habitat types associated with multiple measured traits (e.g., total leaf length, apex length, base width) illustrate the evolutionary potential of Amazonian bryophytes in the framework of habitat differentiation. Future priorities should focus on resource allocation dynamics and ecophysiology in a phylogenetic context to better understand the role of habitat differentiation in speciation processes among Amazonian bryophytes.

Keywords:
adaptation; bryophytes; habitat heterogeneity; morphometry; speciation