This latest edition to the ``Peterson Field Guide'' series seeks to train the reader to recognize patterns that define a woodland. Calling his book a ``field guide to ecology,'' Kricher introduces basic ecological concepts and describes notable field marks that define a particular environment. Twenty-seven types of forest communities east of the Rockies are described in terms of their characteristic indicator species. Illustrative plates, many of which are in color, accompany these descriptions. Seasonal processes within the forest are also discussed. This book, when used in conjunction with appropriate field guides, is an excellent introduction for the amateur naturalist who wants to see the forest as a whole. Recommended. Laurie Bartolini, Lincoln Lib., Springfield, Ill.