MANUAL Part II Visual Assessment of Crown Condition - ICP Forests

26 II. CROWN CONDITION ASSESSMENTS
Hint: Some species produce large amounts of green tissues associated with the flowers (e.g.
Carpinus betulus and Fraxinus excelsior). These tissues contain chlorophyll and contribute to the
carbon budget of the tree. It is recommended that such tissues are included with the foliage mass
when assessing defoliation. As fruiting in such species remains relatively constant from year to
year, annual changes in fruiting will not significantly affect the defoliation estimates.
A1.21 Fruiting (optional Level I and Level II)
Definition
This score is defined as the estimation of fruiting in the crown. Only fruits produced in the year
of assessment are included.
Information on fruiting is useful to have because of its effect on the carbon economy of the tree.
As with flowering, fruiting diverts energy away from other parts of the tree. As with flowering, it
may also have an effect on the future branch structure of the tree.
Especially on beech this parameter may provide very valuable information and its submission is
very much encouraged.
Methods
As with flowering, two assessments are made: of the assessable part of the crown and of the
whole crown. Scoring is:
1 Absent or scarce. The fruits are not seen in a cursory examination.
2 Common. Fruiting is clearly visible.
3 Abundant. Fruiting dominates the appearance of the tree.
Note
Quantitative estimates of both flowering and fruiting can be obtained by the use of litter traps.
However, such data cannot be readily related to individual trees.
A1.22 Secondary shoots and epicormics (optional Level II)
Definition
Secondary shoots and epicormics are used synonymously and are defined as shoots that have
developed from dormant buds on the stem or on branches.
In some species, the development of secondary shoots is the normal part of crown formation. For
example, in Picea abies, secondary shoots develop along the main branches to replace older
shoots that have lost their needles. In other species, particularly broadleaves, the development of
epicormic shoots in the crown and on the stem may reflect increased levels of light penetration
through the foliage of the outer crown.
Scoring of the presence of shoots reveals whether the tree is responding to loss of foliage and
thus the regenerative capacity of the tree. For example, a heavily defoliated Picea abies that has
no secondary shoots is indicative of a tree under extreme stress.
updated 06/2006