This study aimed to test whether metaphyton and phytoplankton in shallow lakes represent
functionally distinct communities shaped by habitat-specific environmental filtering
or whether connectivity between them leads to functional overlap. We combined taxonomic
and trait-based approaches across multiple standing waters using diversity metrics,
multivariate analyses, and regression-based models to assess community differences
and the influence of shoreline development and vegetation cover. Taxonomic composition
differed clearly between communities, with higher richness in metaphyton, whereas
trait composition showed only weak separation. Functional richness and dispersion
were higher in phytoplankton, indicating greater functional space, while higher taxonomic
richness in metaphyton was consistent with functional redundancy. Differences in individual
traits were primarily morphological, with metaphyton characterized by more elongated
and structurally complex forms and phytoplankton by higher proportions of mobile taxa.
These differences are consistent with adaptations to contrasting habitat conditions.
Shoreline development and vegetation cover had limited influence on overall patterns,
although intermediate vegetation cover was associated with higher diversity and patterns
of functional richness suggested increased functional redundancy. The observed functional
overlap is consistent with a potential role of dispersal-driven connectivity or mass
effects between littoral and pelagic habitats, highlighting the importance of considering
both compartments in freshwater biodiversity assessments.
