Experimentelle Untersuchungen zur Stoffauswaschung aus Baumkronen Durch Saure Beregnung

Summary

Acid irrigations (H₂SO₄, pH 2.7) of a young spruce stand with an input of 366 mmol H⁺/m² during 18 events from June to October 1985 caused a 6–7 times larger loss of Mn and Ca, a 4–5 times larger one of Mg, and a doubled one of K and NH₄, when compared with normal irrigations (pH 5.2). During the whole application period the acidified apoplast solution was a sink for NH₃, causing a higher input of NH₄ into the system. At the end of the observation period in November 1985 17% of the proton input are retained in the canopy, mainly puffered by cation exchange. 15% are consumed mainly by HCO₃-input of natural rain and 68% did pass the canopy (54% as H⁺, 14% as NH₄+).