Growth Trends of Swiss Forests: Tree-Ring Data : Case Study Toppwald

1996

S. 199-217

26 Lit. Ang.

Unselbständiges Werk

200072000

In cooperation with other colleagues, concerted research on recent growth trends based on data from tree analyses, permanent plots and from forest inventories was undertaken. This study is based on tree growth analysis of spruce and fir on the permanent plot Toppwald and the trees are compared to earlier sampled trees of the Swiss Sanasilva 1984 study. Climate models are used to detect known influences of weather patterns and climate change; these effects explain 9 to 37% of the growth variance. In the calculated, non-climatic residual data, a long-term time-dependent trend of 4 to 49% of the growth variance was found. This shows that growth of the two species has improved since the beginning of the century. In the most recent period the residuals show, for most cases, an increased growth since 1980. Analysis of the whole time series reveals neither an exceptional rise nor any growth levels which have not been seen or reached earlier in this century.