Liming restores the benthic invertebrate community to ''pristine'' state

After liming of twelve acidified rivulets in central Sweden, the fauna increased its mean similarity to the fauna in unlimed non-acidified references. All species which were found after liming were also found in other waters north and south of the limed area The species composition after liming should thus be considered as typical of the limed geographical area. Before liming, the fauna was characterized by the acid tolerant mayfly Lep tophlebia spp. After liming the fauna was characterized by the acid sensitive mayfly genus Baetis, an important food organism for young brown trout; The restoration of the water quality by liming resulted in an apparently ''pristine'' benthic invertebrate community, enhancing the conditions for salmonid fish.