Temperate forests are mostly made up of deciduous and evergreen coniferous (koh NIF ur us) trees. Coniferous trees, or conifers, produce seed-bearing cones, and most have leaves shaped like needles, which are coated in a waxy substance that helps reduce water loss. These forests have cold winters. In autumn, deciduous trees shed their leaves. In the spring, small plants burst from the ground and flower. Fertile soils are often rich in humus, a material formed from decaying leaves and other organic matter.
Abiotic factors cold to moderate winters; warm summers; year-round precipitation; fertile soils
Biotic factors
Plant life: Deciduous trees drop their leaves and go into a state of dormancy in winter. Conifers have needlelike leaves that minimize water loss in dry winter air.
Animal life: Animals must cope with changing weather. Some hibernate; others migrate to warmer climates. Animals that do not hibernate or migrate may be camouflaged to escape predation in the winter when bare trees leave them more exposed.
Mild moist air from the Pacific Ocean influenced by the Rocky Mountains provides abundant rainfall to this biome. The forest includes a variety of conifers, from giant redwoods to spruce, fir, and hemlock, along with flowering trees and shrubs such as dogwood and rhododendron. Moss often covers tree trunks and the forest floor. Because of its lush vegetation, the northwestern coniferous forest is sometimes called a “temperate rain forest.”
Abiotic factors mild temperatures; abundant precipitation in fall, winter, and spring; cool dry summers; rocky acidic soils
Biotic factors
Plant life: Because of seasonal temperature variation, there is less diversity in this biome than in tropical rain forests. However, ample water and nutrients support lush, dense plant growth. Adaptations that enable plants to obtain sunlight are common. Trees here are among the world's tallest.
Animal life: Camouflage helps insects and ground-dwelling mammals avoid predation. Many animals are browsers—they eat a varied diet—an advantage in an environment where vegetation changes seasonally.
Dense forests of coniferous evergreens along the northern edge of the temperate zone are called boreal forests, or taiga (TY guh). Winters are bitterly cold, but summers are mild and long enough to allow the ground to thaw. The word boreal comes from the Greek word for “north,” reflecting the fact that boreal forests occur mostly in the northern part of the Northern Hemisphere.
Abiotic factors long cold winters; short mild summers; moderate precipitation; high humidity; acidic, nutrient-poor soils
Biotic factors
Plant life: Conifers are well suited to the boreal-forest environment. Their conical shape sheds snow, and their wax-covered needlelike leaves prevent excess water loss. In addition, the dark green color of most conifers absorbs heat energy.
Animal life: Staying warm is the major challenge for animals. Most have small extremities and extra insulation in the form of fat or downy feathers. Some migrate to warmer areas in winter.