Impact of three aquatic invasive species on native plants and macroinvertebrates in temperate ponds

Biological plant invasions pose a serious threat to native biodiversity and have received much attention, especially in terrestrial habitats whereas in freshwater ecosystems impacts of invasive plant species are less studied. We hypothesize an impact on organisms from the water column, but also from the sediment and assessed the impact of three aquatic invasive species Hydrocotyle ranunculoides, Ludwigia grandiflora and Myriophyllum aquaticum on plants and macroinvertebrates. Our results in 32 ponds in Belgium indicate that the reduction in native plant species richness was a common pattern to invasion. However, the magnitude of impacts were species specific. A strong negative relationship to invasive species cover was found, with submerged vegetation the most vulnerable to the invasion. Invertebrate richness, diversity and abundance were measured in sediments of uninvaded ponds and in invaded ponds along a gradient of H. ranunculoides, L. grandiflora, and M. aquaticum species cover. We found a strong negative relationship between invasive species cover and invertebrate abundance, probably due to unsuitable conditions of the detritus for invertebrate colonization. Taxonomic compositions of aquatic invertebrate assemblages in invaded ponds differed from uninvaded ponds. Sensitive benthos such as mayflies were completely absent in invaded ponds. The introduction of H. ranunculoides, L. grandiflora, and M. aquaticum in Belgian ponds has caused significant ecological alterations in the aquatic vegetation and the detritus community of ponds.

Jaar van publicatie:2011

Trefwoorden:aquatic ecology, biological invasions, impact, biodiversity