A concept of forest ecosystem stability and of acid deposition as driving force for destabilization
Loading...
Files
Date
2007
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A theory is proposed which explains the acidification and alcalinization of soils, respectively, as consequence of the discoupling of the ion cycle in the ecosystem. Under the assumption that the ecosystem tends to minimize net proton production or consumption in order to keep the chemical soil state in optimal conditions for growth, the characteristic features of stable forest ecosystems showing high resilience are deduced. A sequence of ecosystem states is described; aggradation phase, stability range I (high resilience), destabilization phase I (humus disintegration), stability range II (low resilience), destabilization phase II (build up of decomposer refuge, podzoli-zation). A continuous input of acidity exceeding the rate of base cation release by silicate weathering within the root zone forces forest ecosystems from the stability ranges into the transition states (destabilization phases). The concept of stress and strain is used to deduce how acid deposition superimposes natural stress factors and may trigger forest damages connected with climatical extremes and pests.