The influence of air pollution on moss-dwelling animals: 1. Aquatic fauna with emphasis on Nematoda and Tardigrada

The influence of air pollution on moss-dwelling animals: 2. Aquatic fauna with emphasis on Nematoda and Tardigrada.-The effects of gaseous air pollutants on the moss-dwelling aquatic fauna were studied along an urban-rural gradient in the region of Zurich (Switzerland).Moss samples from 12 study sites, representing different air quality conditions, were taken in October 1984.Close to 49'000 individuals were extracted.Nematodes and tardigrades were analysed to species level; rotifers were treated as a group.Community structure (species composition and abundance) was related to air pollution.The abundance of nematodes increased with increasing air pollution, while species richness was not significantly affected.In contrast, the number of tardigrade species decreased with increasing levels of SO».The abundance of tardigrades and rotifers varied independently of SO, and NO».Classification and ordination techniques were used to investigate the similarity between .samples or study sites based on environmental characteristics, pollution, flora and fauna.Results suggest that air pollution represents an important factor controlling the composition of nematode and tardigrade communities.At the species level, the abundances of four nematodes (Chiloplectus cf.andrassyi, Aphelenchoides sp. 4, Paratripyla intermedia and Mononchidae sp.) and two tardigrades (Macrobiotus persimilis and Isohypsibius prosostomus) were significantly correlated with air pollution.Thus, the aquatic fauna of epilithic moss cushions could serve as an indicator of air pollution.