The effects of habitat complexity on periphyton biomass accumulation and taxonomic structure during colonization.

Habitat complexity plays a significant role in biological communities, but its effect on periphyton is still poorly understood. For example, the response of periphyton to changes in habitat relative to colonization time remains to be elucidated. Our hypothesis was that habitat complexity positively affects periphyton biomass, algal diversity, and change in species composition, while the response of periphyton to habitat complexity depends on colonization time. To test this hypothesis, we evaluated periphyton on artificial substrate distinct levels of habitat complexity at the intermediate (15 days) and advanced phases of colonization (30 days). Biomass, species richness, and diversity increased with level of structural complexity, but these attributes present significant difference only at the 15th day of colonization. In contrast, species composition changed with the increase of fractal dimension at both colonization times. Algal community response to distinct levels of structural habitat complexity was most significant at the 15th day of colonization. Our results showed that biomass, adaptive strategies groups, and taxonomic structure in periphyton were affected by habitat complexity, but that response was dependent on colonization time. Therefore, we concluded that colonization time is a factor that should be considered in assessing the effects of habitat complexity on periphyton. [ABSTRACT FROM AUTHOR]