Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
p. 728-740 or Chap. 42 Earth’s Ecosystems and the Biosphere 1. Temperature and water -major climatic factors determining the distribution of organisms... 2. Climate -the prevailing weather conditions in an area. • Weather -short term • climate –avg. over long term (year/season). • Both are mainly temperature, water, light, and wind. 3. Climate and biomes. • Climate determines makeup of biomes, the main types of organisms living in an area. Mean temperature and rainfall are correlated with the biomes. Factors Influencing Climate Patterns: 1. Largely determined by sunlight and the planet’s movement in space (affects the season). • The sun’s effect on the atmosphere, land, & water establishes the temperature variations, cycles of air movement, & evaporation of water … responsible for latitudinal variations in climate. 2. Also determined by latitude, air currents, ocean currents, the presence of bodies of water, mountains and continents. • Latitude -degrees north or south of equator. • Mountains & continents change air & ocean currents. Link to Animation1 & 2 • The angle of the Earth’s axis is responsible for seasonal variations on the Earth. Review of Air Circulation • The tropics experience the greatest input and least seasonal variation in solar energy of any region. • Solar energy especially near the equator initiates a global circulation of air, creating precipitation and winds. • Local and seasonal effects on climate. • Bodies of water (oceans) and topographic features such as mountain ranges can affect local climates. • Mountains affect temperature & rainfall greatly. • This creates prevailing air currents. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Four Resources Required by Life (these resources are not evenly distributed) 1. Chemical nutrients to feed and build cells. 2. Energy to power the building of cells. • light for plants & photosynthetic organisms. • food for animals & decomposers. 3. Water(l) to serve as a medium for metabolism. 4. Appropriate temperatures. Earth’s Biomes • Biomes –land/sea areas w/ similar env/similar communities of vegetation. • Plants dominate all land communities and define their biome. Which plants … determine which animals live in the biome. • Land biomes: desert, grassland, tropical rain forest, taiga (tĪ-guh), tundra, temp. rain forest, etc. (bold we will cover) • Aquatic biomes: open ocean, coral reefs, deep sea vents, rivers, etc. Student Presentations on Earth’s Biomes 1. Name the biome 2. Provide its characteristics, what defines it 3. Discuss if the vegetation is lush or sparse, whether diversity of life is great or small 4. Name the major plants and animals (if more than 3 each, just say and many others) 5. Describe some plant and animal adaptations to living in the biome 6. If there is something special, provide it. Deserts • -low rainfall (< 10 inches/yr), often but not always hot. • Vegetation -usually sparse, includes cacti and succulents. Also horned lizards, snakes, kangaroo rat, bighorn sheep, burrowing owl. • Plant Adaptations: shallow roots to quickly absorb H20, waxy coat to prevent water loss • Animal Adaptations: many nocturnal, avoid the heat/water loss. How are snakes adapted to living in the desert? Grasslands • Fertile soils … decomposition of grass over eons. U.S.A. grasslands converted into farmland, the breadbasket of America. Only ~1% of the USA grasslands exist. Adaptations: • Plant germination/growth in the moist spring/fall, dies in dry summer. Too dry for anything but grasses. Plants able to survive fire (roots). • Herbivores must live off dry grass or seeds in summer. Prairie dogs, bison, hawks. Tropical Rain Forests • Near equator, lots of rain, temp. hardly varies, great variety of life forms. Highest biodiversity on the planet! (Number of types of organisms/area.) Adaptations: • Organisms tend to fly or dwell in trees. • When decomposers release nutrients, plants quickly absorb them. • The soil is infertile from this & the rain, why turning it into farmland is very risky. Taiga (Northern Coniferous Forest) • Taiga (tĪ-guh) -largest terrestrial biome on Earth. Long cold winters and short wet summers. • Conifers are adapted to the short growing season, evergreen leaves never drop, ready to go at start. Also waxy coat & small needle size to prevent water loss. • Low biodiversity. • Conifer forests home to various animals, some of which adapt by hibernating. Tundra • Very short growing season. The climate is windy and cold. A layer of permafrost (ground that does not thaw) found below ~1.5 feet, preventing root growth. • Plant adaptations: Low growing plants and shallow roots to avoid wind and permafrost (dwarf willow, dwarf clover). • Animals adapted to the cold (caribou, lemmings, and artic foxes). • Two types of tundra, arctic, found around the Arctic circle, and alpine, found on very high mountaintops. The Open Ocean Includes most of the world’s water & most of the Earth! • Is the desert of the oceans, very little primary production. • Plankton (the producers) adapted to live only at the top (light) and deplete the water’s nutrients. • A great variety of fish, mammals & zooplankton (consumers). Coral Reefs • Dominated by coral and include a very diverse and rich assortment of organisms. • Very high biodiversity (number of types of organisms/area) & primary production. • Extremely sensitive to disturbance. Deep Sea Vents (hydrothermal vents) • Only biome not dependent on the sun! Energy comes from the magma heating water that dissolves sulfur. • Chemosynthetic bacteria obtain energy from hydrogen sulfide to build sugar. Most bacteria adapted to live in nearly boiling water! • All consumers (white clams, mussels, blind crabs, tube worms, fish) depend on chemosynthetic bacteria. • There are other fresh & salt water biomes. • How are fish and ducks adapted to live in a water biome? • What relationship exists between predatory fish and a baby duck? • Next lesson: Ecosystems (p717-728 or ch 41)