Aquatic insects of the Bohemian Forest glacial lakes: Diversity, long-term changes, and influence of acidification
Abstract
Aquatic insects have been studied in five Czech (Černé, Čertovo, Prášilské, Plešné, and Laka) and three German (Grosser Arbersee, Kleiner Arbersee, and Rachelsee) lakes and their inlets and outlets in the Bohemian Forest. All available historical and present records, as well as many unpublished data were summarised.
Of nine insect orders, 70 families, 214 genera, and 373 species/taxa were found in total (Ephemeroptera 20, Odonata 22, Plecoptera 37, Heteroptera 35, Megaloptera and aquatic Neuroptera 3, Trichoptera 46, Coleoptera 58, Chironomidae 113, other Diptera 39). All aquatic insect groups are discussed from the point of view of species richness, influence of acidification, ecological requirements, distributional ranges of species, and species protection.
The lakes were classified into four groups which primarily reflect characteristics of the lake littoral and water chemistry. Available data on Ephemeroptera, Plecoptera, Trichoptera, and Heteroptera from the past two decades were analysed in order to repeal possible biological recovery from acid stress.
A certain degree of recovery has been documented by the increase in species richness of Ephemeroptera and Heteroptera. Yet the lakes have not been colonised by any acid-sensitive species.