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Unit 6: Terrestrial & Aquatic Diversity Chapter 6 & 7 Earth has three major climate zones: Tropical, Temperate, Polar • Chapters 6 & 7 Factors affecting climate: Uneven heating of the earth’s surface: Rays hit equator directly & hit poles indirectly High solar radiation increased evaporation & precipitation Tilt in Earth’s axis Leads to seasonal changes in temp & precipitation Rotation of the earth on its axis: winds are deflected east/west, creates global patterns of prevailing winds that distribute heat & moisture Properties of air, water, & land: Hot air tends to rise, cool, & release moisture as precipitation; Cool air tends to sink, get warmer, & lose its moisture by evaporation, These two properties cause convection cells to circulate air, heat & moisture Ocean currents redistribute heat & influence air circulation; created by: – Wind blowing over oceans – Differences in water density – Also mix waters & distribute nutrients https://www.youtube.com/watch?v=KUU7IyfR34o Winds blowing along western coasts push surface water away from land causes upwelling: deep, cold, nutrient-rich water rises – Nutrients support large pops of phytoplankton zooplankton fish, birds, mammals Coriolis Effect: – In physics, the Coriolis effect is a deflection of moving objects when the motion is described relative to a rotating reference frame – The Coriolis effect makes storms swirl clockwise in the Southern hemisphere and counterclockwise in the Northern Hemisphere • https://www.youtube.com/watch?v=i2mec3vgeaI Important Climatic Events: – El Niňo Southern Oscillation (ENSO) • When prevailing tropical winds blowing westward weaken or reverse • Warms surface water along South & North American coasts suppresses normal upwellings of cold, nutrient-rich water – Causes decline in fish species • Can cause extreme weather in Pacific & Indian Oceans – La Niňa • Reverse of El Niňo • Results in more Atlantic hurricanes, colder winters in Canada & NE U.S., and warmer/drier winters in southern U.S. http://video.nationalgeographic.com/video/el-nino Greenhouse effect- Greenhouse gases warm lower atmosphere: H2O, CO2, CH4 (methane), N2O (nitrous oxide), Gases reflect infrared radiation back to earth’s lower atmosphere Topography (earth’s surface features) can affect climate – Ex: Rain Shadow Effect – Ex: Cities create microclimates: have more pollution, higher temps, & lower wind speeds https://www.youtube.com/watch?v=DoKTTHd-XEQ Terrestrial Diversity • Biomes vary with – Latitude: north & south of equator – Altitude: distance from sea level Desert Biomes Area where evaporation > precipitation Found mostly in tropical & subtropical regions 3 types – Tropical desert: • hot & dry most of year • Few plants • Ex: Africa’s Sahara – Temperate desert: • Daytime temps high in summer, low in winter • Shrubs, cacti; reptiles, birds • Ex: North America’s Mojave – Cold desert: • Winters are quite cold, summers are warm/hot • Ex: China’s Gobi http://video.nationalgeographic.com/video/lizard_thornydevil http://www.bbc.co.uk/programmes/p0037p9f bactrian camel Terrestrial Diversity • Desert Climate Graphs: • Desert Adaptations: – Succulent plants save water by having no leaves, store water in their flesh, & open stomata at night – Evergreen plants have waxcoated leaves to save water – Many animals are nocturnal – Insects & reptiles have thick scales to minimize evaporation – TED Talks: • Ecology from the Air: http://www.ted.com/talks/greg_asner_ecology_from_the_air • http://www.ted.com/talks/frans_lanting_s_lyrical_nature_photos • http://www.ted.com/talks/e_o_wilson_on_saving_life_on_earth • Grasslands Biomes – Enough precip. for grasses, not enough for shrubs or trees – Occur in interiors of continents – Persist b/c of: 1. Seasonal drought 2. Grazing by herbivores 3. Occasional fires Grasslands 3 types: Tropical grassland: Savanna • Warm most of year; alternating dry & wet seasons • Found in Africa, South America, Australia; Acacia trees; many herbivores like elephants, zebra, giraffes, gazelles; Animals have mass migrations to find water; plants adapted to drought, Threatened by grazing of cattle (fecal pavement) Temperate grassland: Prairie • Daytime temps warm in summer, low in winter • Found in North America, South America, Asia • Has deep, fertile, alkaline topsoil • Grasses have thick root network • Animals include prairie dogs, bison, coyote, eagles Cold grassland: Tundra • Most of year is cold • Has Permafrost = frozen underground soil • Hares, voles, lynx, weasel, snowy owl, fox, bears (thick fur) • Canada, Russia • There’s also the Alpine tundra – high mountains • Threatened by oil drilling & mining Terrestrial Diversity • Grassland Climate Graphs Forest Biomes: • Tropical Rain forest • Near equator • Year-round warm temps & high precip. (80F, 75-100 in per year) • Dominated by broadleaf evergreen plants create canopy • High NPP & biodiversity: Parrots, frogs, monkeys, snakes, jaguar, etc. • Nutrient-poor, acidic soil – Temperate Rain forest • NW America • Moderate temps & high precip. • Dominated by coniferous evergreen trees (spruce, fir, redwoods) • Lots of moss • Relatively lower biodiversity due to limited light • Major source for timber • Animals: elk, weasels, owls, bear, cougar, salmon, etc. https://www.youtube.com/watch?v=H9MV5CgPgIQ https://www.youtube.com/watch?v=trWzDlRvv1M https://www.youtube.com/watch?v=btM0A3jOEoc – Temperate deciduous forest • US, Europe • Warm summers, cool winters • Dominated by broadleaf deciduous trees (oak, maple, hickory) dormant in winter, grow leaves back each spring • Lots of birds, rodents, insect, some larger mammals (deer, skunks, foxes, bears) – Taiga/ Boreal forest/Coniferous • South of arctic tundra in N. America, Europe, Asia • Warm summers, cool winters • Dominated by coniferous evergreen trees (spruce, pine, fir, cedar) – Needles prevent water loss • Needles make soil acidic – Slow decomp • Animals: bears, wolves, lynx, caribou, chipmunks, weasels, etc. – Hibernate Terrestrial Diversity • Forest Climate Graphs Types of Aquatic Organisms: Plankton: drifting organisms Phytoplankton Producers/Autotrophs produce 50% of the O2 you breath everyday Ex: Diatoms, cyanobacteria Zooplankton consumers Ex: rotifers, fish & crab larvae Nekton Strong swimmers Ex. fish, turtles, whales, adult jellyfish Limiting Factors: Temperature, light, oxygen, nutrients, Turbidity (cloudiness) Benthos Bottom dwellers Ex. sea stars, clams, crabs, anemones *Watch short videos on plankton http://www.planktonchronicles.org/en/episode/embryos-and-larvae https://www.ted.com/talks/the_secret_life_of_plankton http://education.nationalgeographic.com/education/media/plankton-revealed/?ar_a=1 Aquatic Life Zones Key factors in distribution of organisms: 1. Temperature: Decreases w/ depth 2. Availability of light for photosynthesis • • Confined to Euphotic (photic) zones Decreases w/ depth 3. Dissolved oxygen content • Decreases with depth 4. Availability of nutrients (CO2, NO3-, PO43-) • CO2 increases with depth 5. Turbidity: degree of cloudiness in water • Inhibits photosynthesis Marine Life Zones: Coastal Zone: Intertidal Estuaries: where fresh mixes w/saltwater Estuaries form between Atlantic Ocean and 5 major Georgia rivers -the Altamaha, Ogeechee, Satilla, Savannah, & St. Mary’s Wetlands: land covered with water all or part of year Hydric soil -saturated by water, resulting in anaerobic conditions Services: absorbs pollutants, controls flooding, storm buffer, & provides habitat/nurseries Watch & Answer Questions: Bill Nye wetlands https://www.youtube.com/watch?v=k7wO3W1mWnA • The Savannah River broadens into an estuary about 28 miles upstream from the Atlantic • Sewage & industrial waste Threats: pollution • Mercury contamination from coal fired power plants & the manufacture of chlorine • Savannah Harbor Expansion Project (SHEP) is predicted to affect the fresh/salt water composition impacting flora & fauna Organisms Adaptations Marsh grass (spartina) & cattails flexible stems to withstand tides, vacuoles to store salt, air spaces for oxygen transport (hydric soil not aerated), barriers to block salt Fiddler Crab gills & a primitive lung, to breath in water & on land, burrows for escape from high tide, decrease activity level Cypress Trees Cypress knees (provide stability) *In general organisms will have excretory organs which remove excess salt & water 3. Coral Reefs Coastal Zone: Neritic (shallow area) • Tiny animals or “polyps” secrete calcium carbonate shells • Polyps and zooxanthellae algae = mutualism get O2 & chemical energy get a home & CO2 for photosynthesis FOCUS: Gray's Reef - Sandstone formation (not coral) provides habitat for invertebrates: corals, moss animals (bryozoans), tunicates (sea squirts), sponges, & barnacles. Coastal Zone: Neritic-Coral Reef Services: Biodiversity (Marine equivalent of tropical rain forests) Provides habitat for one-fourth of all marine species Food Recreation Threats: Warmer ocean temperatures = coral bleaching: kills algae Increasing ocean acidity Coastal development Pollution, runoff Overfishing/ trawling Dredging Careless boat operation Ozone depletion- UV rays harm coral *Watch short videos on ocean threats http://www.sciencelearn.org.nz/Contexts/Life-in-the-Sea/SciMedia/Animations-and-Interactives/Marine-ecosystem Open Ocean/Pelagic: Three vertical zones: 1. Euphotic zone: lit upper zone – Phytoplankton perform photosynthesis – Nutrient levels low & d-Oxygen levels high – Have fast swimming, predatory fish (swordfish, sharks, tuna) 2. Bathyal zone – Dimly lit, few producers, Have zooplankton and smaller fishes 3. Abyssal zone Dark & cold, high pressure, No photosynthesis, little doxygen, nutrient levels vary Deep, hot ocean vents (black smokers) w/chemosynthetic bacteria using hydrogen sulfide to create chemical energy *Watch short video on abyssal creatures http://youtu.be/FswYwyke7cc http://www.untamedscience.com/biology/biomes/pelagic-biome/ A lot of the marine fish we eat come from pelagic fisheries (mackerel, sardine & tuna.) Stocks have been over-exploited and some species even face extinction due to overfishing. Clear, well-lit open water, large predators Decreased light & oxygen concentrations, Squids & swordfish Goes down and past the continental slope, pressure is great; food is limited to the debris of dead material that sinks like snow from the above zones. where the continental slope levels off Deep ocean vents (black smokers) w/chemosynthetic bacteria using hydrogen sulfide to create chemical energy https://www.youtube.com/watch?v=ufxGw8EqY5Q • Marine Life Zones: 3 major zones • 3. Benthic Zone: – = The Ocean Floor • Underlies all the other zones – Communities consist of • • • • Bacteria Fungi Seaweed (algae) Invertebrates (sponges, echinoderms, mollusks) • Fish Ocean Threats : *Watch short videos on ocean threats Coastal development Habitat destruction Overfishing, trawling Pollution http://www.youtube.com/watch?v=Uc605ajWIBE Invasive species http://www.nbcnews.com/video/nightly-news/52403911#52403911 Climate change &coral bleaching http://i2i.stanford.edu/AcidOcean/AcidOcean3.htm https://www.youtube.com/watch?v=Wo-bHt1bOsw Ocean acidification Eutrophication(dead zones) http://www.youtube.com/watch?v=ahOmeTOIrRg http://www.smm.org/deadzone/what/top.html Ocean pH is currently around 8.1, models by end of century it may be around 7.7 III. Freshwater Zones Lentic (standing): Lakes Ponds Lotic (flowing): Streams Rivers Organisms & Adaptations: *interactive websites http://tdcms.ket.org/knh/loticcommunities.html http://www.pbslearningmedia.org/resource/knh.entcomm/lenticcommunities/ 4 Lake Zones (lentic): Littoral [lit-er-uh l] zone 1. Rooted plants 2. Shallow, near shore Limnetic zone 1. Open, away from shore 2. Photosynthetic (photic) zone Profundal zone 1. Deep, dark 2. No photosynthesis Benthic zone 1. Decomposers & detritivores Great Lakes -largest supply of surface freshwater in the world Low nutrients Good light penetration High DO Deep waters Low algal growth Small mouth bass, lake trout Oligotrophic Lake High nutrients Poor light penetration Low DO Shallow waters High algal growth Carp, catfish, bullhead Eutrophic Lake Cultural (artifical) eutrophication: input of excess nutrients (fertilizers) causing excess algal growth Aquatic Life Zones • Lake Types Based on Nutrient Levels: – Oligotrophic lakes • Low nutrients and low NPP • Very clear water – Eutrophic lakes • High nutrients and high NPP • Murky water with high turbidity – Cultural (artifical) eutrophication: input of excess nutrients (fertilizers) causing excess algal growth • Oligotrophic lake • Eutrophic lake • Freshwater Degradation: – Dams destroy habitat – Flood control levees and dikes along rivers alter flow & destroy habitat – Pollutants from cities and farms on streams, rivers, and lakes – Draining wetlands for agriculture & development