Crown condition assessment in the LWF plots

Rationale

Crown condition assessment Photo: T. Reich (WSL)

Since 1985, the condition of forests in Switzerland has been monitored through the Sanasilva Inventory. This is based on a systematic sampling programme, using a network of plots. Although the network provides representative results for Swiss forests, the network design is inappropriate for cause-effect research. The LWF plots are providing a variety of ecologically relevant data (including information on soils, vegetation, meteorology, pollutant deposition etc.). It is therefore important to have good information on the condition of the trees in the plots. At the same time, assessing the crown condition of trees in the LWF plots provides an important link between the results from this sub-programme and those of the Sanasilva Inventory.

Project aims

1. to determine the relationships between crown condition and a number of environmental parameters determined on site
2. to provide a link between the LWF and Sanasilva sub-programmes
3. to develop the basis for a better explanation of the trends recorded in the Sanasilva inventory

Methods

A full inventory of the crown condition of all trees > 12 cm diameter is made in each LWF plot at the start of the programme. This is repeated at regular intervals, using a rolling assessment programme so that the work is spread evenly. An annual assessment of the crown condition of trees > 12 cm diameter in a 50x50 m subplot is made. The assessment methods are based on those used in the Sanasilva inventory.

Work plan

Inventories have been completed for the following sites: Alptal, Beatenberg, Bettlachstock, Celerina, Chironico, Davos, Isone,  Jussy, Lägeren, Lantsch, Lausanne, Lens, Nationalpark, Neunkirch, Novaggio, Othmarsingen, Schänis, Visp and Vordemwald. and .     

• Completed and planned inventories (including the 50x50m subplots) are listed in Table 1.

Publications

• Brang P. (Redaktion), 1998. Sanasilva-Bericht 1997. Gesundheit und Gefährdung des Schweizer Waldes - eine Zwischenbilanz nach 15 Jahren Waldschadenforschung. Berichte der Eidg. Forschungsanstalt für Wald, Schnee und Landschaft 345, 102 p.
• Innes J.L., Ghosh S., Schwyzer A., 1996. A method for the identification of trees with unusually colored foliage. Canadian Journal of Forest Research 26(9): 1548-1555.
  
• Innes J.L., Eichhorn J., Ferretti M., Roskams P., 1997 . Visual assessment of tree condition. In: Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests. Hamburg and Prague, United Nations Economic Commission for Europe, International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests), Programme Coordinating Centres.
• Innes J.L., 1998. Role of diagnostic studies in forest monitoring programmes. Chemosphere 36(4): 1025-1030.

Participants

• Matthias Dobbertin
• Christian Hug (Project leader)

Contact

• Matthias Dobbertin
  

• Christian Hug