This project aims the conservation of historical data about permanent plots in Switzerland and monitoring of vegetation in a context of environmental changes (mainly climate and land use).
Permanent plots are currently being recognized as valuable tools to monitor long-term effects of environmental changes on vegetation. Often used in short-term studies (3 to 5 years), they are generally abandoned at the end of projects. However, their full potential might only be revealed after 10 or more years, once the location is lost. For instance, the oldest permanent plots in Switzerland, established by Braun-Blanquet in Swiss National Park or by Lüdi along the Altesch Glacier and on the Schynige Platte were almost lost, although they are now very valuable data. The PPch national data bank that we propose here will allow to ensuring future access to permanent vegetation plots.
At its beginning, the project was granted by the Swiss Federal Office for the Environment (OFEV / BAFU), the University of Lausanne and the services of nature conservation of the Vaud and Valais cantons. It is now fully linked to the position of Dr. Pascal Vittoz at University of Lausanne. There are strong collaborations with the Spatial Ecology group (Prof. Antoine Guisan) for data analyses.
A data bank of both historical and recent permanent plots in Switzerland was created. Simultaneously, the reliability of different sampling methods for vegetation were tested (see bibliography Vittoz & Guisan 2007; Vittoz et al. 2010) and a standardised method was developed. This one was used to set new permanent plots and to create a coherent network to monitor influences of environmental changes on vegetation.
With the help of this data bank, new projects can thus be set up on the basis of these historical data. In the next decades the PPch data bank should prove a useful tool to monitor Swiss vegetation, to test hypothesis, management trials, etc. However, the efficiency of the data bank will depend of the number of plots that it will contain. Do not hesitate to collaborate by sending your data to Pascal Vittoz.