A partire dal 1948 l'Italia si è trovata ad affrontare un nuovo problema rappresentato dall'introduzione dello Sciurus carolinensis, un roditore proveniente dal nord-est America. L'impatto di questa specie è molto sentito da S. vulgaris, sciuride autoctono che non è in grado di sopravvivere alla competizione alimentare con lo scoiattolo americano. Si sono già osservate le conseguenze di questa introduzione in Gran Bretagna ove lo scoiattolo rosso è estinto in quasi tutto il territorio. Così in Italia, nelle zone da tanto tempo colonizzate dallo scoiattolo grigio, si è confermata la progressiva scomparsa di S. vulgaris. Ruolo importante nell'estinzione dello scoiattolo rosso lo gioca anche il parapoxvirus, patogeno che risulta letale per lo scoiattolo rosso ma non per il grigio; questo fa sì che lo scoiattolo americano diventi serbatoio della malattia e aumenti il rischio di contagio per lo sciuride europeo. Ma gli effetti negativi non si osservano solo sullo sciuride nostrano, ma anche sulle coltivazioni corilicole e altre piante in generale a cui viene asportata la scorza per nutrirsi di linfa. Attualmente è in atto il progetto LIFE+ EC-SQUARE per la salvaguardia dello scoiattolo rosso e il contenimento dell'espansione dello scoiattolo grigio. Molto importante è l'azione di eradicazione di questa specie aliena per evitare che varchi le Alpi e il conseguente rischio di estinzione dello scoiattolo comune nella gran parte dell'Europa conservando così la biodiversità. Questa procedura ha creato disaccordi con associazioni animaliste e tuttora si cercano accordi tra il pensiero sociale e il pensiero tecnico-scientifico. Fondamentale è istruire i bambini già dalle scuole elementari sull'importanza della salvaguardia dell'ecosistema, della ricchezza della biodiversità e delle conseguenze di introduzione di specie alloctone nel proprio territorio.
The grey squirrel (Sciurus carolinensis Gmelin) is a rodent from North-East America and its introduction in Italy was noticed for the first time in 1948 in Piedmont, in 1966 in Genoa Nervi, in 1994 in Trecate (NO) and in some sites of western Lombardy where it was released in Lecco (Monticello location) and Park Sud Milano for ornamental purposes. In 1948 a couple of S. carolinensis was introduced in Stupinigi from private; the species flourished and colonized the neighbouring areas, bringing to a gradual disappearance of S. vulgaris L. The problem of the grey squirrel invasion is strongly felt in Italy due to the damages resulted after its arrival. Effects of the allochthonous squirrel colonization can be appreciated nowadays in the UK, where the European red squirrel is on the verge of extinction. The competition between the American squirrel and the European squirrel leads to the disappearance of the native squirrel. Moreover, it is not only the red squirrel to be affected. In fact, also other animals and plants suffer considerable damages. As an instance, hazelnut productions in the Langhe, where many fields are in the proximity of grey squirrel-favorable deciduous forests, is foreseen to diminish. Economically speaking, it is estimated that such financial loss might be 2-3 millions euro per year, corresponding to a decrease of 10-15% on the original crop profit. Similarly, Italy is undertaking the same path of the United Kingdom as when, in 1876, the English began to introduce specimens of grey squirrel in their territories. As a result, the red squirrel is currently confined in some coniferous forest in Scotland and in a few areas of England and Wales. The Great Britain spends today roughly 3 million pounds per year in order to contain the damage caused by the grey squirrel. Considering the consequences that followed the arrival of S. carolinensis in the United Kingdom, the eradication of this animal from Italy is crucial and necessary. it is also essential to act as soon as possible in order to prevent the migration (through the Alps) of this species, which would potentially cause the extinction of the red squirrel in the other European countries.
Diffusione dello scoiattolo grigio in Italia: impatto ecologico e tentativi di eradicazione
TONDELLA, ILIZIA
2011/2012
Abstract
The grey squirrel (Sciurus carolinensis Gmelin) is a rodent from North-East America and its introduction in Italy was noticed for the first time in 1948 in Piedmont, in 1966 in Genoa Nervi, in 1994 in Trecate (NO) and in some sites of western Lombardy where it was released in Lecco (Monticello location) and Park Sud Milano for ornamental purposes. In 1948 a couple of S. carolinensis was introduced in Stupinigi from private; the species flourished and colonized the neighbouring areas, bringing to a gradual disappearance of S. vulgaris L. The problem of the grey squirrel invasion is strongly felt in Italy due to the damages resulted after its arrival. Effects of the allochthonous squirrel colonization can be appreciated nowadays in the UK, where the European red squirrel is on the verge of extinction. The competition between the American squirrel and the European squirrel leads to the disappearance of the native squirrel. Moreover, it is not only the red squirrel to be affected. In fact, also other animals and plants suffer considerable damages. As an instance, hazelnut productions in the Langhe, where many fields are in the proximity of grey squirrel-favorable deciduous forests, is foreseen to diminish. Economically speaking, it is estimated that such financial loss might be 2-3 millions euro per year, corresponding to a decrease of 10-15% on the original crop profit. Similarly, Italy is undertaking the same path of the United Kingdom as when, in 1876, the English began to introduce specimens of grey squirrel in their territories. As a result, the red squirrel is currently confined in some coniferous forest in Scotland and in a few areas of England and Wales. The Great Britain spends today roughly 3 million pounds per year in order to contain the damage caused by the grey squirrel. Considering the consequences that followed the arrival of S. carolinensis in the United Kingdom, the eradication of this animal from Italy is crucial and necessary. it is also essential to act as soon as possible in order to prevent the migration (through the Alps) of this species, which would potentially cause the extinction of the red squirrel in the other European countries.| File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.14240/56877