CHAPTER 20 THE EARTH’S ECOSYSTEMS SECTION 1 : LAND BIOMES Biomes on Land—a biome is a geographic area characterized by specific types of plants and animals. Climate and Species—climate determines where species live; the two most important elements of climate are temperature and precipitation. 1) Temperate Deciduous Forest—broad-leafed trees that shed their leaves in the fall; Deer, foxes, squirrels and songbirds. 2) Taiga—the evergreen, coniferous trees have needles adapted to prevent water loss; moose, bears, wolves, and lynx. 3) Tropical Rain Forest—jungles near the equator with large amounts of rain and little variation in temperature; contain the greatest known diversity of organisms on Earth; tall trees host great numbers of insects, birds, reptiles and monkeys. Canopy—trees of various heights form a continuous green roof. 4) Grasslands (Prairie & Savanna)—grasses, has few trees, with cold winters and intermediate rainfall between that of a forest and a desert; grazing animals such as bison along with prairie dogs and gophers; Savannas are found in tropical and subtropical habitats and mainly in regions with a dry climate, such as East Africa. [Many grazers such as zebra, giraffes, and gazelles feed on the grass; Carnivores, such as lions and cheetahs, prey on these herbivores.] 5) Desert—a region that has little or no vegetation, long periods without rain, and extremely hot temperatures; Animals such as lizards and snakes, and plants, like cacti and succulents, are adapted to conserve water in the desert. 6) Tundra—treeless, frozen plain; very low winter temperatures; short, cool summers; and vegetation that consists of grasses, lichens, and perennial herbs; Caribou, musk oxen, snowy owls, arctic foxes, lemmings, and snowshoe hares are native mammals. SECTION 2 : MARINE ECOSYSTEMS Marine Biomes—The ocean can be divided into several marine biomes, including: 1) Intertidal Zone 2) Neritic Zone 3) Oceanic Zone 4) Benthic Zone Zooplankton—are microscopic animals that drift in bodies of water worldwide; act as one of the primary sources of energy in aquatic systems. Coral Reefs—composed of the calcium carbonate skeletons of thousands of coral polyps. [provides food and shelter for as many as three thousand different species of animals; found primarily in tropical climates.] Estuary—an area where fresh water from rivers mixes with salt water from the ocean; mud flats, bays and salt marshes. SECTION 3 : FRESHWATER ECOSYSTEMS A) Freshwater Biomes—can be divided into three zones: 1) The littoral zone—shallow zone where light reaches the bottom and nurtures plants. 2) The limnetic zone or open–water zone is away from the shore but still close to the surface. 3) The profundal zone or deep–water zone is the zone in which little sunlight penetrates. B) Tributary, River System, and Drainage Basin— 1) A tributary is a stream that flows into a lake or into a larger stream. 2) A river system is a network formed by streams and rivers that flow together. 3) A drainage basin is a region that collects streams (surface runoff) that then become part of a body of water, such as a lake or a river. C) Marsh— A marsh is a treeless wetland ecosystem found in fresh water or salt water.