er in-
n der
Konzen-
hr eng
t um-
e Lóf-
onders
n. Es
e mit
| auf-
n Flá-
‚ringe
ırden
sicht-
"weisen,
>rden,
im Ge-
räden
arten
ten fan-
bstand
eichbar.
nd des-
B die
undten-
ständen
erken-
| kann,
'" tat-
letzten-
rfügba-
nicht;
- 2043 -
von grofer Bedeutung dürfte weiter das Wetter im Folgejahr eines
Dürresommers sein.
3, Enge Zusammenhünge zwischen Trocknisschüden und Standorttypen
sind zu erwarten.
4. Sekundüre Folgeschäden der Dürre wie Buchen-SchleimflufB und auch
Insektenbefall sind durch Luftbildauswertung nicht prognostizier-
bar und auch im Rahmen einer Inventur viel schwerer erfafbar als
unmittelbare Dürreschàden.
5, Altbestände mit wertvollem Holzvorrat werden durch Dürre wesent-
lich stärker gefährdet als jüngere Bestände.
Abstract
The exceptionally dry weather conditions in 1975 and 1976 caused
severe damages not only in spruce but also in beech (Fagus silva-
tica) stands in many areas of the Federal Republic of Germany. As
the wood of dead beech is destroyed very rapidly by fungous decay,
an early cut of the dying trees is the only possible measure of
economic timber preservation. In order to carry out this task, an
early detection of damaged trees is necessary.
1. From CIR aerial photographs taken in August, 1976 some old beech
stands were chosen by random. Each tree of these stands was eva-
luated with regard to possible damage symptoms (discolorations,
losses of foliage). The trees were identified individually in
the field, marked and observed during the growth period 1977.
The portion of trees which were already recognized as severely
damaged in August 1976 contained all of the specimen which died
in spring 1977; some trees of this group, however, showed only
light damage symptoms in 1977.
The degree of drought damage in a forest stand was shown to be
dependant from soil conditions. The appearance of secondary
damages such as beech bark disease and insect damages could not
be predicted precisely; the number of observed stands and trees
was too small for exact results in this field.
2. In an area of 200 km?
the extent of damage was estimated using aerial photos of Sep-
hard wood forest in the state of Hessen
tember 1977. This inventory is described, the results are shown
and explained.
