On 11/4/2012 8:08 PM, Janet wrote:

It certainly is an ecological problem in west Scotland; in woodland
it smothers natural regeneration of native plants, particularly worrying
as older trees die naturally. It's also a host plant of phytopthera
kernoviae and ramorum

http://ucanr.org/sites/sod5/files/147415.pdf

I know shepherds on the north coast, who dislike it because of the
effect it can have on their animals.