Hemenway, a permaculture expert and associate editor of The Permaculture Activist, explains how gardens can function as ecosystems, describes the basic parts of an ecological garden (soil, water, plants, and animals), and shows how to create backyard ecosystems through guilds. Guilds, the author tells us, are groups of plants that function as an ecosystem to provide products for humans, create cover and food for wildlife, nourish the soil, conserve water, and repel pests. A simple example of a g ...