The trees are a place of refuge for a variety of ground-feeding birds, which are at risk of being picked off, when out in the open, by a passing merlin or sparrowhawk. A pair of starlings nests each year in a hole in one of the ash trees, and swallows circle around all five trees in the summer, picking up the many insects that they attract. The young ones do not have cross bills, so nibbling ash trees is much easier than trying to grapple with a pine cone. Most entertaining are the crossbills, which bring their recently fledged young in early spring-just about now in February-to nibble the buds of our ash trees. Many birds and numerous insects inhabit them. They provide shelter for a variety of warblers and finches, which we did not have around us before they were planted, but it is the old trees that are the most important for our ecology. We have planted numerous other trees ourselves-alder, rowan and birch. Indeed, the elm recently seeded a baby elm, which too is doing well. I hope that I am not tempting fate when I say that they all remain in good health. They consist of two sycamores, two ash trees and one elm. About 150 years ago, five trees were planted beside the shepherdвЂ™s moorland cottage that we now own. We are fortunate at Craighead, at 1,100 feet in the hills of north-east Perthshire. When the trees die, the adverse effects extend well beyond the trees themselves. Trees, after all, are part of a much larger ecosystem that includes the birds, animals and insects that inhabit them. These pests and diseases have wider effects, too. We have also seen the devastating effects of the fungus that causes ash dieback, especially among young trees, which have been planted to improve the contribution that deciduous woodlands make to our environment.

About 35 years ago, acute oak decline made its appearance, and more recently the oak processionary moth, which causes rashes and breathing difficulties for some people and animals, arrived here in 2005. I think the elms were the first to go their sad and empty corpses still stand along the edges of fields, as there is no profit to be made from cutting them down. There is of course an aesthetic aspect to this problem. Then there is the threat to trees caused by tree pests and tree diseases. The devastating effect on native species in our rivers by the introduction of signal crayfish from North America to combat European crayfish disease is another example. It is only now being brought under control by eliminating that animal from places where it has caused the most damage, particularly the Outer Hebrides. The damage done to ground-nesting birds by another species imported from North America, the mink, has caused great concern. It is now recognised that the grey squirrel is at the top of the list of the introduced species which are regarded as pests that are damaging, especially to trees. As long ago as 1935, Evelyn Baxter and Leonora Rintoul, in their book A Vertebrate Fauna of Forth, noted that the spread of the grey squirrel in their part of Scotland was likely to be troublesome, and that a good many complaints had already been made about the damage done to trees by that animal. The threats posed by non-native animals which become pests is not a new issue. The issue to which the Motion draws attention is sadly all too familiar to those of us who care about the countryside and the creatures, including the plants and trees, that are to be found there. So it is a very important subject, which has been well recognised. Of course, I look forward very much indeed to hear what he will have to say when his turn comes to speak, and I know that it is largely due to his initiative that so many noble Lords have put their names down to speak-and many noble Lords have told me that they were unable to do so because of time constraints. I can only hope that I can do justice to this crucially important subject in the time available. It was his idea, and he secured the debate just before his appointment as chairman of the EU Committee made it impossible for him to open it himself. Before I go any further, I should explain that I am doing so on behalf of the noble Earl, Lord Kinnoull, who I am glad to see in his place. My Lords, it is a real privilege for me to have been asked to open this debate.

Breaking bad the pests courseforum