For 70 years, people have turned to one book to learn about Northwest trees: Trees to Know in Oregon. This new edition, retitled Trees to Know in Oregon and Washington, expands its scope to cover more territory and include more trees.   The book was first published in 1950. Charles R. Ross, an Oregon State University Extension forester, wanted to introduce readers to the towering giants in their backyards. Since then, Edward C. Jensen has stewarded the publication through several more editions. This edition features several rare species native to southwest Oregon. It also updates scientific names and adds a new section on how Northwest forests are likely to be affected by changing climates. Since its initial publication, Trees to Know has become a mainstay for students, gardeners, small woodland owners and visitors to the Pacific Northwest. Along with all the details on native conifers, broadleaves, and more than 50 ornamental trees, readers will find: More than 400 full-color photos and 70 maps depicting habitat, range and forest type. Easy-to-follow identification keys. Handy guides to help distinguish one variety from another. The story of Northwest forests - past, present and future.