Der Teutoburger Wald als pufferungsschwacher Raum: Gewässerversauerung im Osning-Sandsteinzug

Abstract

LETHMATE, J.; SCHNEIDER, K.: The Teutoburger Forest as a weak buffering area: Water acidification in the Osning-sandstone ridge.- Hercynia N.F. 34 (2001): 161-170. The Teutoburger Forest (Osning) remains unnamed in all lists of weak buffering landscapes, although its sandstone ridge predisposes acidification of soils and spring waters. To quantify exactly the hypothesis of the Osning as an area tending to water acidification, the cation and anion composition of ten forest springs was analysed between April 1999 and April 2000. High concentrations of protons, Al, Pb, S04 and N03 qualified the spring waters as extremely acidified. Quantitative empirical models of alkalinity verify the water acidification. The sum of sulphate and nitrate (S04 + N03 mikreq/l) which correlates significantly with the pH-value was used to map the amount of acidification compared to other weak buffering areas of Germany. With the high mean sum of sulphate + nitrate = 1142 mikroeq/l the sandstone ridge of the Osning fits without contradiction into the geographical picture of acidified forests in the northem highlands of Germany. lts history of acidification and the origin of the acidifying anions sulphate and nitrate are discussed.