A concise and vivid guide to the study of living things in their natural settings. Plants and animals do not exist merely as separate units, they are interdependent ant interacting members of the myriad natural communities which can be seen on walls and wastelands, in hedgerows, parks and gardens. These communities in turn interact in many ways with their surroundings and with neighbouring communities. Slowly some of them completely transform their environments; and comparatively quickly some are threatened and modified by man's thoughtless intervention. Much of the information in this well-illustrated book has previously been available only to specialists. The natural communities which are considered are woodlands, freshwater habitats, hedgerows, parks, gardens, moors, healths, grasslands and coastal habitats as well as walls and wastelands. These are studies of equilibrium and also of change - as can be seen in the fascinating description of how foreign plants become 'naturalized' in a neglected orchard.