Analysis of macroinvertebrate assemblages in natural and artificial wetlands: implications for restoration efforts

The introduction of artificial ponds is a restoration measure to compensate for wetland habitat loss, but a deeper knowledge of the ecological relationships in these environments is needed. Aim of this work has been to enlighten the differences in macroinvertebrate assemblages in artificial and natural ponds, and to consider the relative importance of several variables in explaining the functional and trophic patterns in each ecosystem. The ultimate purpose has been to gain information about the potential role of artificial ponds in ecological networks. Within Parco Pineta, a regional park in Lombardia, numerous ponds and wetlands are present. 24 of them have been chosen to analyse differences in invertebrate biodiversity. They are natural (16) and artificial (8) ecosystems, two of the latter being part of a constructed wetland system created for wastewater treatment. Environmental characteristics of each pond and taxonomic composition of macroinvertebrates have been monitored. Significant (a=0.05) differences were not found in biodiversity among different wetland typologies. Univariate and multivariate statistics showed that the most significant environmental factors related to community composition were water body area and microhabitat heterogeneity, while water quality seemed to have scarce influence. The presence of fish could be identified as a limiting factor. Further analyses have been carried out involving macroinvertebrate dispersion strategies and functional feeding groups in order to evaluate ecological behaviours and trophic web organization in the different kinds of wetlands