Is acidification still an ecological threat

There has been a significant reduction in anthropogenic acid deposition in Europe and North America, and now we need to gauge the rate and extent of ecosystem recovery. Stoddard et al.1 have reported a widespread aquatic recovery from acidification in European ecosystems in response to a fall in sulphate deposition. But many sites in central Europe are showing a significant delay in aquatic recovery from acidification, or even no recovery at all, and only some of them show biological recovery of waters or a recovery from soil acidification. Ecosystem management still needs to consider the consequences of acidification.