I had to allow myself an ironic smile in relation to this topic. One man's 'alien' is another man's economic asset sometimes, for example here in Scotland it is universally regarded that two tree species used in our so called commercial forestry plantations in this country are [a] Sitka spruce - Picea sitchensis, and [b] Lodgepole pine - Pinus contorta latifolia. On my property I have all out war on natural regeneration of the latter here within and amongst our native Scots pine - Pinus sylvestris scotica where I rogue every seedling, or try to, as it reaches a size which allows me to yank it out the ground. Both species have eventually demonstrated to the intellectually challenged & benighted government forestry authority that they are indeed egregiously awful economic and ecological disasters. Both chosen originally for their ability to significantly outgrow their compatriots back in their native Pacific coast habitats all to no purpose as the timber is, as grown here, totally useless for stress grading in house building and other construction and really only fit for newsprint paper and particle boards for flooring. Additionally every year I am regularly requested to send seed of our Scots pine, which has relatively bluer needles that other subspecies, to Christmas tree growers of 'Scotch Pine' in the USA while here in Europe plenty of Christmas tree growers seek the North American Blue spruce for the same purpose. Verily for man is indeed a truly weird species! Iain -- I am using the free version of SPAMfighter. We are a community of 6 million users fighting spam. SPAMfighter has removed 102966 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len/ The Professional version does not have this message