Tropical forest

• They occur near the equator (between latitudes . ⁰ at north and . ⁰ at south). • The major characteristic of tropical forests is their distinct seasons.

Only two seasons are present (rainy and dry). Winter is absent. The length of daylight is about hours and varies little. • The average annual temperature ranges between ° C and °C.

• Precipitation is evenly distributed throughout the year with annual rainfall exceeding mm. • Soil is nutrient-poor and acidic. Decomposition is rapid and soils are subject to heavy leaching. • Tree canopy is multilayered and continuous, allowing little light penetration.

• Flora is highly diverse: one square kilometer may contain as many as different tree species. Trees are - m tall, with buttressed trunks and shallow roots, mostly evergreen, with large dark green leaves. Common vegetation are orchids, bromeliads, vines (lianas), ferns, mosses, and palms. • They are characterized by the greatest diversity of fauna which includes birds, bats, small mammals, and insects.

More than half of earth’s tropical forests have already been destroyed. Fig. . Forest biome Temperate forest • These forests occur in eastern North America, northeastern Asia and western and central Europe.

• Have well-defined seasons with a distinct winter. Moderate climate and a growing season of - days during - frost- free months distinguish temperate forests. Historically biomes are known to move as climate changes. A classic example is the Sahara Desert, which years ago was supposed to be a lush landscape with river flowing through it.

Accordingly, appropriate