BIOL 1001 Chapter : Chapter 30 Notes
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30. 3 what are the principal terrestrial biomes: tropical rain forests i. Rain forests cover less than 5% of earth"s total land area and one-half of the world"s biodiversity ii. Below is a continuous canopy at 90 120 feet (30 40 meters), with a layer of shorter trees iii. Smaller plants have enormous leaves to trap scant sunlight reaching the forest floor iv. Edible plant material near the ground is scarce, so most animals live in the trees, including: tropical rain forests have several layers of vegetation i. The tallest trees reach 150 feet (50 meters) below this birds, monkeys, and insects v. almost all the nutrients are stored in the vegetation, so the soil is relatively infertile: human impacts i. Cutting for lumber and burning for ranching and farming are occurring at alarming rates, estimated at about 20 30 million acres annually under way iii. Fortunately, some areas are being set aside as protected preserves, and reforestation efforts are.
