Lo stato di salute dei castagni monumentali in Ticino e nel Moesano sta peggiorando. È quanto emerge da uno studio condotto dalla studentessa di master Caterina Beffa per l’Istituto federale di ricerca sulla foresta, la neve e il paesaggio (WSL).
Si tratta di piante che possono avere età anche superiori ai 500 anni e un diametro del tronco fino a tre metri e più. I primi dati sullo stato di salute di oltre 300 grandi castagni sono stati raccolti intorno al 2000. Ora Beffa ha riesaminato circa un terzo delle piante inventariate.
I castagni, patrimonio da valorizzare
Il Quotidiano 10.09.2021, 21:00
Il risultato? In vent’anni oltre due terzi degli alberi (67%) hanno subito un declino della salute generale, il 26% ha conservato lo stato di salute iniziale e il 7% ha beneficiato di qualche miglioramento. Quasi un quinto degli alberi, ossia 19 individui sui 101 alberi esaminati, è morto.
Lo studio mostra che la rimozione di alberi concorrenti ha un effetto positivo sullo stato di salute dei castagni. Anche la potatura selettiva dei rami morti o destabilizzanti può incrementare le speranza di sopravvivenza della pianta.
I castagni monumentali possono avere un'età superiore ai 500 anni.
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