forest | Definition, Ecology, Types, Trees, Examples, & Facts | Britannica
forest, complex ecological system in which trees are the dominant life-form. Forests can occur wherever the temperatures rise above 10 °C (50 °F) in the warmest months and the annual precipitation is more than 200 mm (8 inches). They can develop under a variety of conditions within these climatic limits, and the kind of soil, plant, and animal life differs according to the extremes of environmental influences. In cool high-latitude subpolar regions, forests are dominated by hardy conifers such as pines (Pinus), spruces (Picea), and larches (Larix). In the Northern Hemisphere, these forests, called taiga, or boreal forests, have prolonged