From the beginnings of life, organisms have lived together in some kind of grouping. Since the differentiation of plants and animals, communities in which both occurred and interacted have undoubtedly characterized the arrangement of living things on the face of the earth. We know now that there are no habitats in which both plant and animal organisms are able to live, in which both do not occur and influence each other. In contrast, the development of the science of ecology has been hindered in its organization and distorted in its growth by the separate development of plant ecology on the one hand and animal ecology on the other.
The authors were brought together in this task of attempting to correlate the fields of plant and animal ecology by the common belief that it would tend to advance the science of ecology in general. It was this common interest rather than agreement in all matters which led to the initiation of this book as a joint project several years ago. In part, it grew out of the fact that the junior author's experience in dealing with the marine communities of the Puget Sound region had led to the discovery of community phenomena paralleling those found on land and fitting the system of classification in use by the senior author.
The phenomena under discussion naturally bring up the question of the community processes, concepts, and nomenclature. A zoologist may be unfamiliar with various ecological terms in use among plant ecologists, and the reverse is also usually true. Here the writers have not introduced all the terms which they are inclined to use in their individual papers, designed for a more limited group of readers, but have attempted to substitute less technical terms. Those terms applicable to communities are given to aggregations of organisms sufficiently well known to enable the reader to build up a fairly clear conception of the whole, so that the terms may be applied to the proper grouping. For example, the term biome has been applied only to those communities in which studies have established something of the processes of development and the character of the final stage or . . .