ISSN:
1573-2932
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract The serious decline of forest trees in Quebec and adjacent areas of the U.S. parallel those observed in Germany. In certain locations, in both cases, K deficiency is now occurring on glacial tills and outwash soils and is associated with a low concentration of exchangeable K+ and a high molar ratio of exchangeable Ca+ ions to K+ ions in the soil. This deficiency results from the so-called Ca-K antagonism in which an increased concentration of Ca2+ ions blocks the entry of a reduced concentration of K. Mg deficiency is occurring on granitic soils and results from a low concentration of exchangeable Mg2+ and a high molar ratio of A13+ ions to Mg2+ ions. The role of the parent rock, weathering reactions and atmospheric inputs are discussed in relation to the changes that have resulted from the cumulative effect of acid deposition. The changes in storage, transfer and losses of cationic nutrients in soil and trees can explain the development of these imbalances, which are still increasing, and are resulting in these forest declines.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00298653
