Oggi 21/09/2019 ore 15:48

The vegetation landscape of the Mediterranean basal floor

Under this vegetation plan, although it must be recognized that the frequency of certain entities and plant morphology in some environments are obviously related to anthropogenic influences, we may recognize many aspects of vegetation and a rich floristic cortege.

Thus, also the suggestive presence of the small colony of Papyrus (Cyperuspapirus) at the Quadare source of the river Fiumefreddo.
These species were once present in colonies of special wetlands in Sicily or along some rivers like the River Ciane at Syracuse, now they risks extinction everywhere because of the draining of the wetlands and the irrational exploitation of the water resources.

This has led, during the centuries to the gradual decay of the phenotypic characteristics of the ecotype populations of papyrus, and the river Fiumefreddo of overwhelming aspects of riparian vegetation, under tougher and more competitive conditions of persistent water scarcity, and the disappearance of those few aspects of aquatic vegetation specified in ethnic territory.
Until a few years ago, in the cool, clear waters of this river set up a rich vegetation composed of floating submerged species (Myriopbyllum, Potamogeton), while in the bends where the water flows more slowly flourished some interesting species of buttercups and Iris Yellow (Iris pseudacorus).
Here the autumn came with an extensive bloom along the river shores and among the dense populations of Cannuccia d'acqua (Phragmites australis) and major mazzasarda (Thypha latifolia).Viole_dell_etna
Quite different is the flora along the coasts of Etna: here for the intrinsic characteristics of these places, subjected while bathing to a considerable anthropogenic disturbance, they survive and they are recognised for their showy flowers, often close to marginal areas, the Violaciocca of the sea (Vlatthiola tricuspidata) or Pancrazio of the sea (Pancratium maritimum).

A characteristic feature of thermophilic environments of this vegetation plan is the stain of vegetation Euphorbia arborea (Euphorbiadendroides), which plays a definite ecological and floristic role, despite its spread relegated to the margins of intensively cultivated agricultural areas or in abandoned land and rugged ridges or in rock spikes.
Represents an association plant physiognomic distinguished by the characteristic appearance of Euforbia tree, which is capable of giving even a hint of colour and liveliness to those landscapes sometimes desolate, unproductive sites in that territory of Etna that is placed between Pozzillo (East side) and Bronte (West side).

A landscape that is perhaps not appreciated is that one offered by the Holm Oak (Quercus ilex), the only species of oak in this ever-green Etna along a broad belt that in the past had crops.
The Holm is recognized as a species originating in the Mediterranean region but has also been introduced in the coldest places, due to its capacity to adapt easily to different climatic conditions, have consented their development even in Western Europe.

Its foliage dense and rounded, of a deep green colour, which becomes the spring-green or yellow ocher and gold, stands at a distance between the old lava flows that have been already colonised by the vegetation and retains its grandeur when the dull edge of lava fields, at the first autumn rains, is awakened and enlivened by an ashs mantle of a lichen, Stereocaulon the vesuvianum.
Where the particularly favourable conditions and the lack of anthropogenic influences have allowed for the creation of the ilex forest formations, the floristic composition and structure of the vegetation show a distinctive Mediterranean character of our landscape plants.
Elsewhere, the ilex, assumes a distinct physiognomy according to the changing climate patterns, particularly because of rainfall and atmospheric moisture.

In areas of increased aridity, in the territory included between Belpasso and Bronte, the vegetation is characterised by Holm Bagolaro Etna (Celtis tournefortii) by Elah (Pistacia terebinthus) and by the Euforbia bush (Euphorbia characias).Ginestra_dell_etna
Due to the variety of the climatic conditions offered by the different slopes, the holm is accompanied by certain species of deciduous oaks, the Etna Broom (Genista aethnensis) or the Orniello (Fraxinus ornus), the hornbeam (Ostrya carpinifolia) and sporadically the laurel (Laurus nobilis).
Different soil and weather conditions affect the distribution, on the slopes of Etna of the two species of Bagolaro, the common Bagolaro (Celtisaustralis) and Bagolaro Etna (Celtis tournefortii).

The first, also known as White Elm or Spaccasassi is often found at an altitude of around 400 meters, where it is, solely in those areas that have not yet been reached by the urban expansion of the various towns of Etna, of more or less dense and thick forests and with species of average height easily recognised by their leaves parchment, ovatolanceolate, pointed, but mainly for their small fruit, blackish when ripe, with a very hard stone but edible.
Ecologically well-differentiated is the grouping plant, characterized by Bagolaro Etna, available on a clearly defined area marked by a peculiar xerothermophilous and therefore well circumscribed and included among Belpasso and Nicola, on the southern side, and Bronte, on the North-West.
In some of these environments, an original grouping plant diversification in which are included, so as to constitute a unique aspect of the Etna plant landscape, exemplary of high shrubs of Terebinto (Pistacia terebintbus), from the intricate foliage of a reddish colour, and compact heads of the Euforbia rounded bush (Euphorbia caracias).

On the south slope with more favourable conditions for the species, appear the deciduous oaks that together with the Holm, occupy a predominant role in the physiognomy of the vegetation landscape.
The use of seeds of Bagolaro for the extraction of oil to burn is unknown to us, only the leaves are occasionally used to feed goats and sheep. In this regard, it should be recognised the negative influence of the excessive load of cattle, due to the massive nibbling prevents the natural renewal and dissemination of the species.

Furthermore, both the Etna Bagolaro and the common Bagolaro, are subjected to very severe cuts as the wood is highly valued for its resistance to termite and for its considerable toughness and flexibility.
When the Bagolaro is grown for ornamental purpose, it develops harmoniously, assuming the aspect of high trees that are interesting enough to have an ornamental interest for the villas and gardens of a quality not less than certain non-indigenous essences but with more successful dissemination.
We rarely find the black Carpino and (Ostrya carpinifolia) and the Orniello, the mother’s tree (Fraxinus ornus), spread over in large isolated individuals or gathered in modest pure populations of cultivated areas. Frequently these tree essences along with the Holm of typical mixed forest (forest with deciduous sclerophyllous), preferably on the slopes of Etna area in which prevail particularly favourable rainfall.
These unique aspects of forest vegetation, which brings together deciduous trees (Oak, Hornbeam and Ash tree) with evergreen tress (Holm oak) are fairly common on the Italian peninsula and the islands and should be connected to the simultaneous presence in the territory of elements of the flora of the continental regions of Europe, mixed with elements characteristic of the flora of the Mediterranean type.

This leads to a coexistence of species adapted to withstand the rigors of winter, thanks to some physiological mechanisms such as dormancy and fall of leaves and others have leaves that are provided of highly specialized adaptations in relation to the drought and to heat resistance during summer which binds them to a limited environment that has a local-level microclimate and a unique topography and soil conditions.
In these particular types of woodland is assigned a composition and a typical appearance of ilex Mediterranean-mountain.
They are located at the eastern limit of Etna, only between Acireale and Linguaglossa and at altitudes between levels fairly close to the sea to about 1,000 meters above sea level. Conditions of high humidity and abundant rainfall in this area also can lead to a sharp reduction in the upper altitudinal limit of ilex.
Moreover, the presence of certain characteristic species of plant associations of oak and its floristic cortege, consent to detect in this territory the presence, an aspect of southern mountain areas with deciduous oaks such as those described in the peninsula.
Finally we can ensure that the physiognomic characteristics of these mixed cenosis have suffered major changes over time due to repeated anthropogenic interventions designed to align the composition of the tree in the forest, favouring the existence of species considered more convenient in economic terms.
Different, either because of taxonomic problematic or for the knowledge of ecology of the species involved, is the distribution in the territory of Etna of the deciduous oaks, such as Quercus virgiliana, Quercus dalechampii, Quercus congesta, improperly included in the "Roverella”.

On these three entities phytogeographical investigation, together with biometric observations conducted in populations of distinct characters for taxonomic distribution and height, even for the different soil conditions, has established a direct correlation between the three species and the different pedoclimatic consequences.
In light of recent acquisitions, it is considered appropriate to distinguish, at a lower altitude and in clearly restricted stations at around 300 meters, Quercus Virgiliana, easily recognizable for the development of the acorn and in particular for the structure and shape of the dome, and for the greater development of the leaf area.
Elsewhere, at the same altitude and higher up to the limit of the species, grouped in consortia or pure or mixed forests, or in isolated individuals, we recognize the Quercus dalechamcpii and Quercus congesta.
Observing the floristic composition and extent of these forests on the slopes of Etna with the deciduous oaks, it is possible to deduce the conditions of more or less marked thermophily affecting both the Mediterranean horizon itself, and the upper zone of the Mediterranean.
It is the higher altitude area, where the oaks are located (upper mediterranean) with high humidity and temperatures more rigid, to accommodate the typical forest of oak (Quercus cerris).