Cation mobility in forest soils : Air Pollution and Forest Decline. 14th International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems

1989

S. 399-400

4 Abb., En, Zfsg. En

Unselbständiges Werk

200034731

The distribution and proportions of different forms of Ca, Mg, K, Fem Al and Mn were determined in jumus and mineral soil samples from a wide range of forest site types. Acid-induced cation exchange and dissolution were investigated in laboratory experiments. K was found to be relatively unaffected by acid additions owing to the fact that most of the K is already free in soil solution under the pH conditions prevailing in Finnish forest soils. Ca was the major cation exchanged following acid addition. However, the exchange of Mg was proportionally greater than that of Ca. In the humus Al was not released into solution until the pH fell below 3. Aluminium hydroxides in the B horizon, on the other hand, were dissolved when the pH fell to around 4.