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The upper Trebbia Valley vegetation, rather rich and various,
mainly include wooded formations, among these stand out the
beechwoods and chestnut woods.
The beechwood is part of the natural vegetation
of the Ligurian mountain belt. The beech appears in the Ligurian
Appennino when the climate tends to become damper with heavy
rain and cooler where the altitude increases (generally over
900-1000 mt).
Below these quotas the beech grows because it takes
advantage of the damp coolness offered by some little valleys
sheltered and protected by dry winds: here the beech
is uncommonly present at a quota a bit higher than 700 mt,
where the remarkable dampy air often manifests itself by
the valley floor fog.
The few arboreal species that join the beech are the maples,
the rowan and the "saliconis" (Italian term). In the damp and
shady brushwood the knotty geranium, the sweet euphorbia and
the daphne mezereum bloom .
The original structure of the beechwood is generally modified
by the cutting, but big coppices with secular beeches can
still be found in the highest areas and along the whole Aveto-Trebbia
ridge. However the bearing of the beech is irregular on the
slopes exposed to the wind, and you can find bushes
with knotty and twisted trunks.
Chestnut woods and
mixed woods
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Frequently you can find chestnut woods.
They originate from cultivation as they do in the rest of
the Liguria Region because man increased the chestnut tree proliferation
as it is more profitable than other arboreal species
such as oaks .
Today in Trebbia Valley we can still admire some beautiful
chestnut tree as the ones in the “Fairies’ Wood”,
in Fontanigorda. In the brushwood of the chestnut woods
the female fern always appears.
Giving up chestnuts’ cultivation was due by different
reasons, among which the parasitary disease also known as
cancer of the bark, the “ink disease”, people
moving to the city, the smaller competitiveness of the chestnut compared
to other products.
Today chestnut woods are mainly coppices, rich of shrubby
and herbaceous species.
They tend to turn into mixed woods of broad-leaf, particularly
black hornbeam, manna-ash, laburnum and wild cherry.
Their brushwood is rich of primroses, anemones, liverworts,
violas, scillas.
A particular type of wood is the locust tree, the false
acacia; it grows on alluvial or detrital soils, in the low
zone along the Trebbia river, near Gorreto.
Among the woods on the hill there are important woods of
Turkey oak, a frequent oak to be found above all on the central
and southern Appennines.
The alnetis are woods where the white or black alder prevail
under damper conditions of soil in compared to the beech
tree. We mainly observe them along the shores of watercourses
or in little valleys, or where the water tables are superficial
because of waterproof rock layers.
Reforestation has also been made in the Trebbia Valley,
generally employing arboreal "pioneer" and "colonizers" species
such as the black pine and the woodland pine.
These can survive to difficult environmental conditions and
sometimes preventing erosive phenomenons and facilitating
the return of the wood. Unfortunately reforestation is often
so dense and impenetrable that light doesn't succeed in filtering,
the ground becomes too acid and life in the brushwood
is almost impossible.
(Article based on the publication "Naturalistic
Itineraries" by the Communità Montana Alta Val
Trebbia ) |
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