Phytophthora ramorum moves closer

SheffieldLass · #1 (**permalink**) 10-11-2010, 11:38 PM

Phytophthora ramorum

I've been hearing about this killing Japanese Larch in the south west and Ireland, where they are felling the larch like crazy as it is spreading very fast. See map
Forestry Commission - pests and diseases - P ramorum outbreak map

I heard yesterday that it has apparently now reached Sherwood Forest. The Forestry Commission are not planting any more larch for the time being, and I understand there are plans to fell all the larch on the North York Moors plantations within the next 5 years, to try to prevent it spreading to other tree species. I hadn't realised until checking out the FC website that it is the same thing that is affecting bilberry, and that it also affects sessile oak, beech, ash and other trees, and that rhododendron was one of its first hosts here, so it is a particularly worrying pathogen. It is responsible for the death of a lot of oaks in America.

Forestry Commission - Plant Health - P ramorum FAQs

So enjoy your larch trees whilst you still can see them in good numbers, and the larch associated fungi. I wonder what effect it will have on Suillus grevillei, which is so common at the moment. P ramorum doesn't appear to have affected European or hybrid larch yet. I'm not sure what sort of percentage we have of the different sorts of larch, so I'm not sure if the felling will be done on all larches or just the Japanese larch. There is a fear that it will jump to Sitka Spruce and other commercially important conifers. As it also affects sessile oak and bilberry and birch, I can understand the reasons for this action. That is a big swathe of the abundant tree and shrub species of upland Britain.

Melanie