Effects of macrophyte architecture and leaf shape complexity on structural parameters of the epiphytic algal community in a Pampean stream

Abstract

Habitat heterogeneity is one of the main factors determining distribution of organisms, and vegetation is of primary importance in shaping the structural environment in aquatic systems. The effect of macrophyte complexity on macroinvertebrates has been well researched; however, much remains to be revealed about the influence of complexity on epiphytic algae. Here, we used fractal dimension to study the effect of complexity at two scales, macrophyte architecture and leaf shape, on several parameters of the epiphytic algal community (number of individuals, biomass, taxon richness and diversity) in a Pampean stream. Four submerged macrophyte species with different complexities and associated algae were sampled in late spring, summer and autumn. Important differences were found in fractal dimension of the whole plant and leaves among macrophyte species. The particulate organic matter and chlorophyll a associated positively to leaf fractal dimension, but not to plant fractal dimension, partially supporting the hypothesis of a positive effect of macrophyte complexity on periphyton biomass. No association was found in fractal dimension with algal abundance, taxon richness or diversity. Complementary, a mesocosm experiment was performed with plastic imitations of different plant fractal dimensions. After four weeks, there were differences in chlorophyll a and autotrophy index between treatments that suggested a positive effect of complexity on autotrophic periphyton biomass. These results indicate that the wellknown positive effect of macrophyte complexity on macroinvertebrates might be partially explained by a positive effect of complexity on periphyton biomass.

The role of annual macroalgal morphology in driving its epifaunal assemblages

“…A greater habitat complexity is related to a larger number of habitats that in turn are associated with a higher number of organisms and species (McAbendroth et al, 2005;Ferreiro et al, 2013). The second objective of this study was to explore the role of macroalgal morphology in shaping the epifaunal assemblages.…”

Morphological forms of two macrophytes (yellow water-lily and arrowhead) along velocity gradient

“…Previous literature emphasizes that hydrological conditions, mainly velocity of water, are a crucial factor in the spread of different macrophytes forms (Dijkstra & Uittenbogaard 2010;Kőrs et al 2012;Ferreiro et al 2013;Li et al 2013). Different emerged, floating and submerged morphological forms are adaptation to water movement (Kőrs et al 2012).…”

“…Contrarily, constraints resulting from hydrodynamic stress contribute to the development of new features and functions by the different submerged and emerged forms of macrophytes. Such features and functions include, for example, modifications in shape of leaves, spatial organization of plant biomass, type of clonal growth and offspring production (Puijalon & Bornette 2006;Ferreiro 2013). A good example of hydrodynamic stress tolerance can be mosses, which have small body size.…”

The disturbance-driven changes of periphytic algal communities in a Danubian floodplain lake

“…Giorgi et al, 2005;Ferreiro et al, 2013). This is particularly expressed in the wetland microhabitats where periphyton development can be totally 02p11 suppressed during the periods of massive development of floating macrophyte (McCormick et al, 1998).…”