Piante che rischiano l'estinzione: il frassino excelsior in Inghilterra

La stampa inglese sta seguendo con molta attenzione la moria  del frassino colpito da un fungo che si insedia nel sistema linfatico e che non è eradicabile con nessun fitofarmaco.
Ci dovrebbe preoccupare il fatto che troppe essenze arboree vengono colpite da  parassiti invincibili, ricordiamo  l'olmo, il castagno,le drupacee (Ciliegio,mandorlo,susino,albicocco,...),la vite attaccata da l'escoriosi, le palme (comprese quelle autoctone del mediterraneo),l'eucalipto e altre ancora.

Le cause sono molteplici: il trasporto delle piante attraverso i continenti, la selezione genetica rivolta solo al mercato ;le varietà selezionate dai coltivatori erano quelle più rustiche e che producevano frutti più sapidi ed abbondanti, oggi  i criteri sono  molto cambiati, la ricerca del profitto è il solo obbiettivo.

http://www.bbc.co.uk/news/science-environment-20253767

Owen Paterson: Ash dieback will not be eradicated

By Mark Kinver and Matt McGrathBBC NewsEnvironment Secretary Owen Paterson: "The scientific advice is that it won't be possible to eradicate this disease"Continue reading the main story

Ash dieback outbreak

• Ash disease in Scotland
• Ash dieback checks in N Ireland
• Why is dieback making headlines?
• Pest and disease threats to trees

Environment Secretary Owen Paterson has acknowledged that ash dieback, a disease that threatens the UK's ash trees, will not be eradicated.Announcing the government's action plan to tackle the disease, Mr Paterson said efforts would focus on slowing its spread through the countryside.Diseased young trees would be removed and destroyed, he added.But the action plan stated that there were no plans to remove mature trees, which are important for wildlife.It added that efforts would also focus on developing resistance to the disease.Mature ash trees will not be removed from the landscape, the government's action plan saysConservation groups welcomed the government's assurance that no diseased mature tree would be cut down."The scientific advice is that it won't be possible to eradicate this disease now that we have discovered it in mature trees in Great Britain," Mr Paterson said."However, that does not necessarily mean the end of the British ash."If we can slow its spread and minimise its impact, we will gain time to find those trees with genetic resistance to the disease and to restructure our woodlands to make them more resilient."He told reporters that the arrival of ash dieback meant his department would have to reconsider its priorities."If we are going to really do something radical on the way we handle our forestry in the future and change the priorities, we are going to have to shift resources within Defra.Continue reading the main story

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Regulation must be put in place to ensure this does not happen again”

Martin HarperRSPB"There will be some things we do in Defra now that we are going to have to stop doing."Speaking at a briefing, Defra chief scientific adviser Prof Ian Boyd said: "By next season, we could potentially have resistant forms of ash growing in this country."We need to put in scientific research to try and get genetic markers for resistance so that we can go out into our current woodlands that have not been infected and identify trees that might survive relative to those who might not survive."