Modelling soil nitrogen: the MAGIC model with nitrogen retention linked to carbon turnover using decomposer dynamics.

We present a new formulation of the acidification model MAGIC that uses decomposer dynamics to link nitrogen (N) cycling to carbon (C) turnover in soils. The new model is evaluated by application to 15-30 years of water chemistry data at three coniferous-forested sites in the Czech Republic where deposition of sulphur (S) and N have decreased by >80% and 40%, respectively. Sulphate concentrations in waters have declined commensurately with S deposition, but nitrate concentrations have shown much larger decreases relative to N deposition. This behaviour is inconsistent with most conceptual models of N saturation, and with earlier versions of MAGIC which assume N retention to be a first-order function of N deposition and/or controlled by the soil C/N ratio. In comparison with earlier versions, the new formulation more correctly simulates observed short-term changes in nitrate leaching, as well as long-term retention of N in soils. The model suggests that, despite recent deposition reductions and recovery, progressive N saturation will lead to increased future nitrate leaching, ecosystem eutrophication and re-acidification.

Retrospective analyses and future predictions of snowmelt-induced acidification: example from a heavily impacted stream in the Czech Republic.

We have combined a long-term hydrochemistry model (MAGIC) with a model that predicts short-term transient changes in hydrochemistry (pBDM) during hydrological events in order to improve the temporal resolution of retrospective analyses and future predictions of streamwater acidification. The model has been applied to a heavily impacted catchment in the Czech Republic. Spring flood acid-neutralizing capacity (ANC), pH, and inorganic monomeric aluminum (Ali(n+)) were simulated for the years of 1860, 1900, 1930, 1950, 1965, and 1985, measured in 1999, and predicted for 2030 using two different emission control scenarios. If the emission reduction according to the current legislation scenario is implemented, the model predicts that the spring flood pH, ANC, and Ali(n+) will recover close to the level of the 1950s by 2030. This will occur despite the annual average chemistry being farfrom having recovered to that level. The results suggest that the recovery of spring flood events is faster then the recovery of annual average chemistry and that much of what is won by further emission reduction will not be fully realized on an annual time scale.

Modeling and monitoring of long-term acidification in an upland catchment of the Western Ore Mountains, SE Germany.

Modeling and monitoring of acidification patterns in a limed forest catchment in the Ore Mountains, SE Germany are presented. A lumped-parameter model, MAGIC, satisfactorily reproduced the main parameters of stream water chemistry. Despite repeated whole-catchment liming, between 1993 and 1999 stream water pH increased from 4.3 to only 4.6, while calcium concentrations declined slightly. Stream water sulfate concentration declined from 687 to 396 microeq l(-1), and the pronounced effect of deposition decline during the 1990s was probably more important than liming.

Dental care for institutionalized geriatric patients in Germany.

This investigation determined the level of dental care for institutionalized geriatric patients residing in nursing home facilities. A total of 364 patients from nine different geriatric care units within the city of Berlin were involved in this study. On average the patients were 84.9 years old. Women represented 87.3% of the patients. A standardized questionnaire and a clinical examination of the mouth were utilized to assess patient satisfaction with geriatric care, their general medical status and their oral health status. The results demonstrated that patients in geriatric care did not undergo routine dental check-ups. Oral hygiene was sufficient in only 12.6% of the patients, and prosthesis hygiene in 45% of the cases. Only 37.6 of the dentures exhibited sufficient retention and stability. In 80% of the patients dental treatment was necessary. Recommendations for improvement of dental care delivery to institutionalized geriatric patients are given. It has to be concluded that dental management of institutionalized geriatric patients is an essential yet presently underfulfilled service.