306 Apical shoot architecture
Dictionary: d_apical_shoot
Apical shoot architecture is defined as assessment of growth patterns of the topmost twigs of crown of Fagus sylvatica.
The beech architecture model allows recognising vitality anomalies in time series. From a distance apical shoot architecture indicates typical growth patterns, which can be assessed using binoculars.
Methods
Only the top most twigs of a beech’s crown are suitable for assessment of the apical shoot architecture. If there is a good visibility of the top of the sample trees, it can be assessed during summer assessment. It is recommended to derive a concluding estimation by using the weighted value of three observation values, e.g. using a clockwise pattern at 11 hrs, 12 hrs and 13 hrs in the very top part of beech crowns.
If there is only a limited view of the top of trees (for example in dense stands), it is recommended to carry out the assessment in the dormancy period.
The assessment is recommended (mandatory for Fagus sylvatica on core plots) once every 3 years, starting in 2010.
Classification
1 - Exploratory phase: Apical shoots and upper side buds form long shoots. Flat, longitudinal, expansive shoot development.
Drawing by ROLOFF, 2001
2 - Intermediary form between 1 and 3: In crowns representing code 2 the assessment detects as well shoots in exploratory phase as shoots in degeneration phase.
3 - Degeneration phase: Only apical bud forms a long shoot. Shoots of side buds are stunted. Spear-shaped development of main shoots with reduced side shoot formation “spear-shaped”.
Drawing by ROLOFF, 2001
4 - Intermediary form between 3 and 5
5 - Stagnation phase: Stunted long shoots, claw-like appearance because of pluriannual short shoot chains
6 - Intermediary form between 5 and 7
7 - Resignation phase: Dieback of twigs of the topmost part of the crown or even the whole crown itself.
8 - Regeneration phase. Phase with obvious regeneration: From worse phase to a better form on the same branch.