Global Biomes & Ecosystems

Click to start, & click to go to next slide BIOMES Global Biomes & Ecosystems

Seagull Desert Marine Tundra Cetacean Savannah Chapparral Freshwater Next

Desert • A desert is a biome that receives less than 25 cm [10 in.] of precipitation. Hot deserts occur closer to the equator than cold deserts. • Deserts often occur in the rain shadow of mountains. • Deserts are the driest places on our Earth. • Plants use a survival strategy called Drought-Resistance which allows then to live through the worst desert conditions. • Animals adapt to desert conditions by aestivating – burying themselves in the ground and sleeping through the dry season.

Marine • Oceans cover nearly three-quarters of the Earth surface. • Flowering plants are absent from the oceans, except around the edges. • The amount of sunlight determines which organism can live in each layer of the ocean. • The open ocean is the least productive of all ecosystems. • The depths of the ocean are perpetually dark, and most of the food consists of dead organisms that fall from the surface. • Although oceans are huge, they are becoming steadily polluted. • Go to http://www.scilinks.org/to read about threats to oceans, and enter keyword HE083

Tundra • Tundra (TUN dra) biome is without tall trees, where grasses and tough shrubs grow in the frozen soil. • Tundra extends from the Artic Circle to the North Pole. • Underneath lies the permafrost, permanently frozen soil. • Taiga (TY guh) biome is dominated by conifers and characterized by harsh winters. • Taiga biome occurs just below the Artic Circle. • Taiga is also called northern coniferous forest. • Next to deserts, the Tundra is the driest place on our Earth.

Savannah • Tropical Savannah (sah VAN uh) plain or grassland characterized by scattered trees, low rainfall, periodic draughts, and high temperatures. • Savannahs have the most fertile soil of any biome. • Today, temperate grasslands occupy about 12 percent of the Earth, as compared to the 42 percent they once occupied. • Temperate Grasslands occur in several continents and are known as Prairies, Steppes, and Pampas. • The amount of rainfall determines what type of grasses will grow in an area, the height of the grasses as well as the depth of their roots. • Animal adaptations include large flat teeth for chewing tough grasses, thick fur coats which are shed in spring, burrowing underground to shield themselves from fire, predators, and the elements. • Threats to grasslands are overcultivation, and overgrazing. Because the soil is so fertile, most of the world’s tallgrasses prairies have been plowed under.

Chaparral • Chaparral is a biome that occurs in mid-latitudes, about 30 degrees north and south of Equator. They occur in areas with Mediterranean climate • These areas are know for their hot, dry summers; mild, wet, winters; and slight variations in seasonal temperatures. • Chaparral plants are mostly low-lying evergreens and small trees. • Plant adaptations include small, leathery leaves that resist water-loss; resprouting from small bits of surviving tissue after a fire. • Animal adaptations include camouflage, adapted for seasonal food. • Worlwide, the biggest threat to chaparral is human development.

Freshwater • Freshwater ecosystems include lakes, ponds, rivers, & streams, and the areas where land and water come together, knows as wetlands. • In the shallow areas close to the shores of lakes and ponds, aquatic life is diverse and abundant. • The deep areas or benthic (BEN thic) zones have very little sunlight thus making photosynthesis impossible. • Wetlands are areas that are covered with water for at least part of the year. • The main types of wetlands are marshes and swamps. • Near churning waters, rhizoids are used by plants such as mosses to attach themselves; some nymphs use hooks in their legs to cling to any stable surface. Some fish have streamlined bodies to present less resistance in swift, strong currents. In calmer waters, fish glide rather than swim vigorously and plants send down roots into the rich sediments. • The importance of wetlands as purifiers of wastewater, and absorbers of otherwise hazardous floodwaters is now recognized. Wetlands are also vitally important as habitats for wildlife. • The federal government and most states now prohibit destruction of certain wetlands. • Many industries still pollute rivers when manufacturing products. Other methods of pollution are runoffs containing toxic pesticides or excess nutrients from fertilizers used to grow food, gardens, and lawns. Dams alter river flow and may destroy habitats.

Biomes of the World

Citations • Photo Credits… • Deciduous • http://multimedia.lycos.com/results.asp?query=Deciduous+Biomes • Rainforest • http://multimedia.lycos.com/results.asp?query=Rainforest+Biomes • Tundra • http://www.kidzwerld.com/site/p2044.htm • Desert • http://www.kidzwerld.com/site/p1985.htm • Aquatic • http://www.kidzwerld.com/site/p1951.htm • Hydroenergy • http://www.kidzwerld.com/site/p1375.htm • Marine • http://ridge.icu.ac.jp/biobk/BioBookcommecosys.html • http://www.kwc.edu/academic/biology/marpg1.htm • http://www.biology.plymouth.ac.uk/Research/MBERG.html • Fresh Water: Yamile’s picture from Julienne. • Community and Ecosystems dynamics (Global Biomes image) • http://mac122.icu.ac.jp/biobk/BioBookcommecosys.html Reference Holt Environmental Science, Harcourt, Brace & Company, 2000

Global Biomes & Ecosystems