D1: Tree vitality and adaptation

Action Group D1 is a demonstration action that is carried out on a limited number of intensive monitoring plots (~140). The Action Group embraces data assessment and collection. The related coordination and evaluation is conducted in Action C1-tree-30. Based on the experiences gained during past forest monitoring and by testing new methods D1 wants to answer two central questions:
What are key indicators of tree vitality?
Which tools and methods allow scientifically sound operational monitoring of tree vitality in European forests?

Tree vitality can be characterised by different parameters:

• Visual assessment of crown condition, such as stand structure indices, defoliation, removals and annual mortality
• Discolouration, flowering and fruiting, crown form and morphology, with special emphasis on the assessment of damage causes
• Forest growth
• Litterfall
• Phenology (exemplarily using webcams)
• Leaf area index measurements

Improvement and testing of methods

In FutMon D1 existing methods for monitoring tree vitality will be used and further developed. Basis for development of monitoring methods are the definitions given in Manual of ICP Forests and the FutMon Field Protocols for vitality, phenology, biomass/foliage and growth. The Field Protocols already are an advancement of the ICP Manuals as they broaden the number of mandatory parameters and their interlinkages. In addition, the parameters are incorporated into new data hierarchy and coding. Under FutMon D1 data will be assessed and reported by the participating countries according to both existing method descriptions. This allows the comparison of old and new methods and will help to improve the quality and comparability of results from the 38 European partners of FutMon. Additionally, D1 will test a new concept for reporting tree removals and mortality.
For example, basic factors altering the results from old and new methods will be identified and their influence will be quantified (Field Protocol Vitality). Especially with regard to the following parameters, the Field Protocols improve the procedures described in the ICP Manuals:

• Assessable crowns as depending on field position of assessment
• Tree age
• Fruiting
• Crown diameter related distance to neighbours
• Apical shoot architecture (ROLOFF)
• Species

Special focus on European Beech

Another task is the assessment of tree vitality and adaptation with a special focus on European beech (Fagus sylvatica L.).
Within Action C1-tree-30, the Northwest German Forest Research Station (NW-FVA) evaluates data obtained from the new methods and existing long-term records. By testing the innovative airborne LiDAR technology, the NW-FVA even extends the choice of methods which are tested for the assessment of tree vitality. The derived 3-D data set has the potential to deliver, besides leaf area index (LAI), information on tree structure data.