Reproduction of the Etna Birch
The Etna birch (Betula aetnensis Raf.) is an endemic plant of Sicily, where it lives on the Etna lavas in extreme conditions, adapting to very strong climatic excusions.
Suitable breeding habitat –
Betula aetnensis is an endemic plant of Sicily that grows on the soils of lava origin of the eastern and western slopes of Etna in extreme conditions and adapting to very strong climatic excursions and at an altitude varying between 1000 and 2100 m. s.l.m ..
Its range coincides, in part, with the Mediterranean mountain belt of the Etna area, in which it is present with two wood populations.
Betula aetnensis, due to its strong and punctual endemism, can find a reproduction site especially in the area and in the pedoclimatic conditions in which it is currently found and grows.
The reproduction can take place through dispersion of the seeds mainly through the wind, torn away directly from the catkins. These can be transported, up to 80 m from the mother plant, even on the surface of the snowflakes. This second dispersion system may be the most effective.
However, most of the seeds are non-viable as early as the second year so the abundance of viable seeds in the forest soil is, therefore, probably supported by the annual production of a huge amount of seeds.
It is well known for seed germination that it is favored by stratification. However, several studies show that light during germination reduces or replaces the need for layering.
Betula aetnensis is, most likely, a relict that survived the glaciation which contracted and strongly isolated its range until the formation of a separate species. The area, as mentioned, coincides, in part, with the Mediterranean mountain belt of the Etna area, with a minimum altitude around 1000 m a.s.l. and a maximum around 2100 m a.s.l., in which there are two wooded populations, one of small size on the western side (about 0.235 km2) and a larger and more representative one on the north-eastern side (about 4 km2).
The Etna birch is clearly placed among the objectives of the Etna Natural Park of safeguarding and recovering the environmental heritage and any protection or management intervention cannot absolutely ignore the acquisition of in-depth knowledge
on the autecology of the species and on the plant communities that it itself determines. To date, little is known about this plant and given the importance of protecting an endemic species that symbolizes the Etna area as well as the significant role it assumes as a pioneer species on lavas, further investigations are appropriate.
The main objective is to investigate the B. aetnensis woodland formations, studying their floristic array, plant communities and their synecological significance and to deepen the knowledge on the ecology of germination and the capacity for natural renewal and maintenance of its populations.