Crown condition

State of the crown is assessed every year, from mid-July to end of October. Compared to assessment in the plots of systematic monitoring, more parameters of forest health state are assessed. Under the ICP Forests Programme 17 plots is included, where mortality, social position, crown shading and visibility, defoliation in 5% steps, discoloration (colour changes of assimilation organs), fruiting and secondary shoots, leaf size, crown morphology, and symptoms of damage by biotic and a-biotic agents are recorded. Detail evaluation of forest damage is done in close co-operation with the Dept. of Forest Protection of the FGMRI.

Detailed investigation of tree vitality and adaptability under the FutMon Project was done within 4 existing ICP intensive monitoring plots (D1), according to the Method as given in the ICP Forests Manual. The aim is to improve the parameters and to unify the methods of evaluation at international level with respect to often very different natural conditions.

Detailed investigation of tree vitality and adaptation within D1 plots is focused to:

  • Detailed stating of the age of individual trees in the monitoring plot.
  • Fruiting of Fagus ssp. and Quercus ssp. according to the litterfall analyses (weight of fruits and their parts (ha/year-1). Litterfall collection and analysis is done also within the intensive monitoring plots.
  • Stating of relative distance of „neighbouring“ trees in the stand within the monitoring plot was replaced by the parameter of crown shading (ICP.
  • Study of crown „architecture“of the top branches in the beech crowns. It is based on the presumption that the distance of terminal and lateral branches is typical for some growth models characterizing tree health state.
  • new concept of registration of mortality and recording of dead and removed trees.

Having in mind, that defoliation assessment is quite individual and depends on the observer, international calibration courses are organized every year, where the differences in the assessment are evaluated. The aim of the courses is not to change individual approach but to get realistic information on the health state of forest stands across the state border.