Littoral species diversity and biomass: concordance among organismal groups and the effects of environmental variables

Abstract

Biomass and species diversity (richness and evenness) of littoral organisms were explored in 27 sites in three basins of the large Lake Saimaa system in eastern Finland. The basins differed in degree of nutrient loading and trophic status. Six organismal groups, i.e., phytoplankton, periphyton, macrophytes, crustacean zooplankton, benthic macroinvertebrates and fish were studied. Factors affecting the biomass and diversity of these groups were explored by multiple stepwise regression analysis. The biomass of different groups was explained by the same variables, mainly nutrients, while diversity was associated with different environmental factors among the studied groups. The biomass of periphyton, phytoplankton, zooplankton, and fish correlated significantly with each other. There was also an apparent association between the biomass of macrophytes and that of benthic invertebrates. However, no significant correlations were found among the diversity of the studied groups. In accordance with previous studies, our results did not support the existence of species-rich hotspots or the possibility of using any surrogate taxon to reveal overall biodiversity. Thus, for conservation planning, biological surveys should include extensive collection of taxonomic groups and organisms at all trophic levels.

A test of the association between Lake Habitat Quality Assessment and macroinvertebrate community structure

“…Both macrophyte PVI and extent of macrophytes lakewards were found to be associated with littoral macroinvertebrate abundance. Dense macrophyte stands support many species of macroinvertebrate, probably through increased habitat complexity, availability of food and refuge from predation (Weatherhead and James, 2001;Tolonen et al, 2003Tolonen et al, , 2005. While not surprising that metrics of littoral macroinvertebrate community richness increase with presence and diversity of macrophytes, it is important that the use of LHS is not weighted in such a way that it is effectively a surrogate for a survey of macrophytes.…”

“…Sampling was done in August 2006. Benthic sampling was carried out using a bilge pump suction sampler (Whale s Gusher 30) with a stiff 38 mm bore tube (after Tolonen et al, 2001Tolonen et al, , 2005. At each distance from shore, suctioning was carried out for 30 s in a transect across the habplot.…”

Effect of removal of free-floating macrophytes on zooplankton habitat in shallow wetland

“…Macrophytes can have dramatic effects on the physical structure of aquatic habitats (O'Hare et al, 2006;Smokorowski and Pratt, 2007) and create a heterogeneous mosaic at different scales. Some studies have suggested that structural heterogeneity of macrophytes mediates trophic interactions among various biota (Jeppesen et al, 1997;Pelicice and Agostinho, 2006) and significantly influences the biodiversity of the zooplankton community (Tolonen et al, 2005). Among animals that use aquatic macrophytes in freshwater ecosystems, zooplankton are located at an intermediate level of the food web and play a key role in transferring energy and materials within the food web (Wetzel and Likens, 2000).…”

Aquatic insects associated with two morphologically different submerged macrophytes, Lagarosiphon ilicifolius and Vallisneria aethiopica, in small fishless ponds

“…Invertebrate density and therefore biomass has been shown to be positively associated with macrophyte biomass aquatic environments (Hargeby et al 1994;Palomäki and Hellsten 1996;Tolonen et al 2005). Thus, in the current study, differences in macroinvertebrate abundances may have been partly due to differences macrophyte biomass among the ponds.…”