Nutrient dynamics in three Scots pine ecosystems along a deposition gradient in eastern Germany since reunification

摘要

In the SANA programme the changes of immission and deposition regimes are studied in the new states of Germany since reunification. Within the ecological part of the programme, the presented subprojects aim at calculating nutrient balances in all relevant compartments of three comparable Scots pine ecosystems along gradients of SO_2 and NO_x immissions as well as dust deposition rates. Via chemical analysis of precipitation, seepage water, soil, and plant compartments a distinct differentiation of the three pine stands can be demonstrated. The nitrogen contents of needle samples from the Roesa experimental area which is located close to the highly industrialised area around Leipzig and Halle are on an over-optimum level and indicate unbalanced nutrition, e.g. with respect to low phosphorus or magnesium contents. Sulphur contents are on a high level at the experimental sites located within the industrialised areas. At present, large amounts of sulphur and calcium stored during decades of high deposition are released from the soil at these sites. This may result in nutritional disorders like a low availability of phosphorus and/or in an increased potential for soil and groundwater acidification.