There are approximately 400,000 American elms planted in villages, towns and cities throughout Saskatchewan. Of these, roughly 90,000 are in Saskatoon and 100,000 in Regina. Up to 90% of the street and boulevard trees in older neighbourhoods within these communities are American elms. There are thousands of miles of farm shelterbelt made up in part or in whole of American and Siberian (also called Manchurian) elms. American elms began to be planted extensively in Saskatchewan in about 1905 because they are the ideal street tree for use in this province. American elms are not an exotic species in Saskatchewan; they grow naturally in river valleys throughout the province and are thus able to survive the natural stresses of limited precipitation, cold winters and hot summers. In addition to natural stresses, American elms are better able most other species to withstand the stresses placed on trees in populated locations: eg. trampling, pruning and shaping to ensure visibility, and pollution. Even the oldest planted American elms in Saskatchewan are relatively young when compared with the normal mature age for the species; under ideal conditions American elms can live more than 400 years. Using criteria established by the International Society for Arboriculture that are accepted by Real Estate associations and insurance companies across North America, the American elms planted in villages, towns and cities in Saskatchewan can be valued at more than a billion dollars. Unless appropriate action is taken, Saskatchewan's American elms could be virtually eradicated in less than a decade by Dutch Elm Disease. Dutch Elm Disease is caused by a fungus that was introduced North America from Europe in the 1930's.The fungus blocks the tree's water conducting system. There is at present no cure for DED. It is spread by minute beetles that require dead and dying elm wood as breeding sites. The most effective way of controlling Dutch Elm Disease is to ensure that dead and dying wood is removed from live trees, and that dead and diseased wood is immediately destroyed through burning or burying. The sudden loss of our American elm trees would have a devastating impact on the quality of life in Saskatchewan villages, towns, cities and rural areas: e.g. Landscapes would be dramatically changed, air quality would deteriorate significantly, wind shelter and shade loss would result in large increases in heating and air conditioning,costs, and habitat for both migratory and resident bird populations would be destroyed. Other short lived or less hardy tree species might also die as they lose the wind shelter and moderating micro-climate created by the elms.