Adapted from Yosemite National Park by Jeffrey P. Schaffer

When you hike in the mountains, you anticipate seeing certain plants and animals in a given habitat. You quickly learn, for example, that junipers don't grow in wet meadows, but corn lilies do. Corn lilies, in turn, don't grow on dry rock slabs, but junipers do. Likewise, you would expect to find garter snakes in wet meadows and western fence lizards on the dry rock slabs, but never the reverse. Thus you could group plants and animals by their habitat. In this book, this classification is based on the dominant plant or plant type of a habitat simply because plants are the most readily observed life forms. Such a group of life forms is called a plant community, even though it includes animals as well as plants.

Because animals move, they can be harder to classify. Birds, for example, typically have a wide-usually seasonal-range, and therefore may be found in many plant communities. In the following list of communities, a species is mentioned in the community in which you, the visitor, are most likely to see it. In addition, only the more prominent and/or diagnostic species are mentioned. To mention all would fill an entire book-Yosemite Valley alone has about 400 species of grasses and wildflowers and thousands of species of insects! Common names, particularly among wildflowers, vary from book to book, so I have attempted to use either the common names appearing in authoritative texts or in popular guidebooks that I feel are the most accurate. To save space, grasses, ferns, lower plants, trout, and invertebrates have not been included.

The following plant communities are listed in approximate order of ascending elevation and decreasing temperature. These plant communities aren't the final word in plant-animal classification, since each community could be further subdivided. For example, Lionel Klikoff identified eight vegetational patterns in the subalpine Gaylor Lakes area (Hike 46), near Tioga Pass. Each pattern is the result of a different set of microenvironmental influences.