Atmospheric deposition and N status of German beech (Fagus sylvatica) forest

Abstract

The deposition situation of 1800 forest monitoring sites in Germany for the year 1989 could be explained by four factors (three, if the sea salt impact is excluded) with the help of a factor analysis. The factors were grouped into five deposition types with typical compounds and regional patterns. The results of the correlation analysis between N deposition components and parameters describing the N status of 51 beech forests revealed that the human induced increase of N input into forest ecosystems significantly influences important ecosystem parameters. However, not all of the observed effects can be interpreted as cause‐and‐effect relationships because of the lack of detailed data, for example, on soil solution and especially time series, but there are some clear trends. A significant impact of N deposition on low buffered beech forests could be detected. High N deposition corresponds with higher amounts of organic matter, higher C and N stocks in the organic layer as well as increased C/N ratios. Beech trees on sites with low Ntotal deposition have significant lower N content in their leaves. These findings indicate a higher N saturation of low buffered beech forest sites due to high N depositions. The study revealed a strong demand for time series data on intensive monitoring plots in beech forests. The findings should be further evaluated taking into account the trend towards declining deposition rates. Efforts should be strengthened to model atmospheric deposition – both site specific and on large scales.

Keywords:

• Deposition
• Nitrogen status
• Beech forests
• Environmental monitoring
• Multivariate statistics
• Deposition type