Ecosystem Diversity & Change Part 2

Transcription

1 Biome Regions with similar types of life Ecosystem Diversity & Change Part 2

2 Terrestrial & Aquatic Diversity Chapter 6 & 7 Earth has three major climate zones: Tropical, Temperate, Polar Climate is the average weather pattern (precipitation & temperature) for an area over a long period of time (30 1,000 years) & is influenced by latitude, altitude, and ocean currents Chapters 6 & 7

3 Terrestrial Diversity Altitude Mountain Ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Deciduous Forest Latitude Tropical Forest Tropical Forest Deciduous Forest Coniferous Forest Tundra (herbs, lichens, mosses) Polar ice and snow

4 Desert Biomes evaporation > precipitation Tropical A: hot & dry; B: succulents (no leaves, store water in their flesh, open stomata at night); Africa s Sahara Temperate A: hot summers, cold winters; B: Shrubs, cacti; reptiles (nocturnal, thick scales to minimize evaporation; North America s Mojave Cold A: Winters are quite cold, summers are warm/hot B: Bactrian camel; China s Gobi bactrian camel Ecology from the Air: A= Abiotic B= Biotic Desert Threats: Development Soil destruction by off road vehicles Soil salinization from irrigation Storage of toxic and radioactive waste *take a long time to recover from disturbances slow plant growth & nutrient cycling, lack of water, & species diversity

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6 DESERT BIOMES Polar desert (northwest China) Tropical desert (Saudi Arabia)

7 Desert Climate Graphs:

8 Grasslands Biomes *Persist b/c of Seasonal drought, Grazing, Occasional fires Tropical Savanna (Africa, South America, Australia) A: Alternating dry & wet seasons; B: Acacia trees; elephants, giraffes; Animals have mass migrations to find water; plants adapted to drought; Threats: over grazing (fecal pavement) *solution: rotational grazing Temperate Prairie (North America, South America, Asia) A: warm summers, cold winters; Has fertile topsoil B: Grasses have thick root network; Animals include prairie dogs, bison, coyote, eagles; Threats: farmland urban development Cold: Tundra (and Alpine tundra) Canada, Russia A: during cold, short summer bogs form; Permafrost= large carbon A= Abiotic B= Biotic reservoir that contains methane & CO 2 ; B: Dwarf shrubs, reindeer(thick fur) & hordes of mosquitos during summer Threats: oil drilling, pipelines, roads, & facilities *ANWR estimated billions of barrels of oil, would require roads, facilities drilling sites; Impacts loss of nesting grounds, disrupt hibernation, displace organisms; Fragile ecosystem- slow growth & decomposition, low diversity, poor soil

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10 GRASSLAND BIOMES Polar grassland (arctic tundra) (Fort Yukon, Alaska) Tropical grassland (savanna) (Harare, Zimbabwe)

11 Grassland Climate Graphs *services: stores carbon, erosion control

12 Forest Biomes Tropical Rain forest (Near equator ) A= Abiotic B= Biotic A: Warm temps & high rainfall, Nutrient-poor acidic soil, quick decomposition, nutrients taken up immediately or leached out by rain B: Dominated by broadleaf evergreen plants create canopy, High NPP & biodiversity Threats: farming, cattle production, logging Temperate Rain forest (NW America) A: Moderate temps & high precip., coastal B: Coniferous evergreen trees (spruce, fir, redwoods), elk, bear, cougar, salmon, etc. Threats: logging *services: support energy flow & nutrient cycling, reduce erosion, absorb water, store carbon, regulate temperature, provide chemicals for medicine

13 Temperate deciduous forest (US, Europe) A: Warm summers, cold winters, thick leaf litter, slow decay; B: Dominated by broadleaf deciduous trees (oak, maple), birds, rodents, insect, deer, skunks, foxes, bears Threats: degraded more than any other biome, logging, urban expansion Taiga/ Boreal forest/coniferous (South of tundra) A: Cool to Warm short summers, cold winters, Slow decomp. acidic soil due to falling pine needles B: Coniferous evergreen trees (spruce, pine, fir, cedar-waxy, needle leaves prevent water loss), bears, wolves (Hibernate) Threats: logging, off road vehicles * 2 types of forest fires: surface- burns away leaf litter, helps control destructive insects, stimulates germination; crown- tree top to tree top, burns entire tree, kills wildlife, increases erosion

14 Protect old growth forests (uncut 200 yrs. + ) by relying on tree plantations *could supply most of the worlds wood used for industrial purposes (i.e. papermaking) Harvesting Trees requires roads which lead to erosion, increase sediment runoff, & habitat fragmentation. Selective cutting- small group of mature trees are cut down Clear cutting- quick, efficient, for maximum profit, leads to erosion, habitat fragmentation, water pollution Tropical forests store 1/3 of terrestrial carbon; Amazon basin could become grassland if current burning & deforestation continues. Management: full cost pricing, kenaf (paper alternative- requires less pesticides & space), reusable vs. throw away items Fuelwood crisis: Haiti was 60% covered w/forests now 2%; alternatives to fuel wood solar ovens, solar powered hot plates Reduction of tropical rainforest deforestation w/debt for nature protect forests for debt relief, Conservation Concessions pay to preserve, Green belt Movement plant Trees & cut down on deforestation

15 FOREST BIOMES Tropical rain forest (Manaus, Brazil) Temperate deciduous forest (Nashville, Tennessee)

16 Forest Climate Graphs

17 AQUATIC BIOMES Ecological Services: Climate Moderation, CO 2 Absorption, reduced storm impact (mangroves, barrier islands), habitats, nursery areas, Economic Services: Food, pharmaceuticals, recreation, employment, oil & natural gas Ocean Lakes Coral reefs Mangroves Rivers

18 Types of Aquatic Organisms: Plankton: Drifting organisms Phytoplankton Producers/Autotrophs produce 50% of the O 2 you breath everyday Ex: Diatoms, cyanobacteria Zooplankton consumers Ex: fish & crab larvae Nekton: Strong swimmers Ex. turtles, whales, adult jellyfish Benthos: Bottom dwellers Ex. sea stars, clams, crabs, anemones Limiting Factors that decrease w/depth: Temperature, Light, Oxygen Limiting Factors: nutrients, Turbidity (cloudiness) *Watch short videos on plankton

19 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, control flooding, act as a storm buffer, & provide habitat/nurseries Watch & Answer Questions: Bill Nye wetlands

20 Threats: The Savannah River broadens into an estuary about 28 miles upstream from the Atlantic Sewage & industrial waste 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

21 Organisms Marsh grass (spartina) & cattails Adaptations flexible stems to withstand tides, vacuoles to store salt, air spaces for oxygen transport (hydric soil not aerated), barriers to block salt Fiddler Crab Cypress Trees gills & a primitive lung, to breath in water & on land, burrows for escape from high tide, decrease activity level Cypress knees (provide stability) *In general organisms will have excretory organs which remove excess salt & water

22 Neritic Zone FOCUS: Coral Reefs: Tiny animals or polyps secrete calcium carbonate shells Polyps and zooxanthellae algae = mutualism get O2 & chemical energy get a home & CO 2 for photosynthesis Services: Biodiversity (Marine equivalent of tropical rain forests, *Valuable compounds for pharmaceuticals), Provides habitat ¼ of all marine species, Food, Recreation Threats: Warmer ocean temperatures = coral bleaching: kills algae Increasing ocean acidity Coastal development Pollution, runoff Overfishing/ trawling Dredging Ozone depletion- UV rays harm coral

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24 Open Ocean/Pelagic Zone: Euphotic zone: lit upper zone Phytoplankton perform photosynthesis Nutrient levels low & d-oxygen levels high Fast swimming, predatory fish (sharks, tuna) Bathyal zone Dimly lit, Have zooplankton and smaller fishes Abyssal zone Dark & cold, high pressure, No photosynthesis, little d- oxygen, 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 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.

25 Ocean Threats : Coastal development Habitat destruction Overfishing, trawling Pollution Invasive species Climate change &coral bleaching Ocean acidification Eutrophication(dead zones) *Watch short videos on ocean threats

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28 Ocean ph is currently around 8.1, models by end of century it may be around 7.7

29 Lake zones entic (standing): Lakes Littoral [lit-er-uh l] zone: near shore Limnetic zone: away from shore Photosynthetic (photic) zone Profundal zone: Deep, No photosynthesis Benthic zone: Decomposers & detritivores Great Lakes -largest supply of fresh surface water in the world Lotic (flowing): Rivers Economic Services: Food, drinking water, hydroelectricity, recreation, employment Ecological Services: Flood control, climate moderation, groundwater recharge, habitat

30 Lake Types Based on Nutrient Levels: Low nutrients Low NPP Good light penetration High DO Deep waters Low algal growth Small mouth bass, lake trout High nutrients High NPP Poor light penetration Low DO Shallow waters High algal growth Carp, catfish, bullhead Oligotrophic Lake Eutrophic Lake Cultural (artifical) eutrophication: input of excess nutrients (fertilizers) causing excess

31 Oligotrophic lake

32 Eutrophic lake

33 Freshwater Degradation: Dams destroy habitat by flooding above dam & decreasing flow below the dam; sediments get trapped behind the dam 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

34 O 2 CO 2 O 2 CO 2

35 Producers /Autotrophs/ 1 st trophic level Perform photosynthesis: Or chemosynthesis 6CO H 2 S C 6 H 12 O 6 + 6H 2 O + 12S\ Ex. Plankton, phytoplankton, moss, grass, bacteria Consumers aka heterotrophs: Herbivores: catepillar Carnivores: spider Omnivore: bear Scavenger: vulture Detritivore: worm Decomposer bacteria & fungi Digest on molecular scale & return nutrients back to environment

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37 Both Producers & Consumers Perform Respiration Aerobic respiration: making energy from sugar w/ oxygen Anaerobic respiration/ fermentation: energy gained w/out oxygen. End products include methane gas (CH 4 ), ethyl alcohol, acetic acid, and hydrogen sulfide

38 Review 1.Where is some energy transferred to along the food chain? 2.How many trophic levels are in the diagram? 3.Where do all organisms ultimately get their energy from? 10% Rule (Ecological Efficiency) Only 10% of the energy is transferred from one trophic level to the next. Energy flows one way! Bozeman energy flow in an ecosystem

39 1. What are some abiotic components in the diagram that are directly important to the tree? 2. What is the primary consumer getting energy from? 3. How is the secondary consumer dependent on the producer?

40 Most of the energy, mass, numbers are at the bottom of the food chain! Many producers are needed to feed fewer primary consumers which feed fewer secondary consumers which feed fewer tertiary consumers

41 Solve the following energy pyramid problems [Use the 10% law across each trophic level.] 1. In this food chain, we could hypothetically assume that for every kilogram of biomass in the osprey eagle, it would require kg of shrimp to keep the food chain balanced. 1 kg 2. The snapping turtle lives in a small pond, where its major prey is bass. In turn, the bass primarily eat minnows. This snapping turtle weighs 40 pounds. If the pond has 10 mature snapping turtles of this size, how many pounds of minnows are required to support them?

42 A snake weighs 2 lbs. Ecologists estimate 2000lbs. of grass plants exist. How many snakes can the ecosystem support? snakes mice grass plants

43 lbs. 1,000,000 lbs. 10,000, 000 lbs. Fill in the biomass for the top trophic level in the ecological pyramid above. At maturity a lion weighs 500 lbs. Ecologists estimate 10, 000, 000 lbs of grass plants exist in the ecosystem. How many adult lions can the ecosystem support?

44 How Fast Can Producers Produce Biomass? Gross primary productivity (GPP): the rate at which producers in an ecosystem convert solar energy into biomass *Measured in Kcal/m 2 /year Net primary productivity (NPP): the rate at which producers do photosynthesis minus the rate at which they do respiration

45 Some ecosystems have higher NPP than others:

46 Biogeochemical Cycles: Human Impact on hydrologic cycle Over pumping aquifers Increase runoff & erosion by replacing vegetation w/buildings & asphalt Draining wetlands for development (urban & ag.) increases flooding Global Warming increase evaporation & precipitation

47 Hydrologic (water) Cycle Evaporation from plant leaves Rain, sleet, snow Movement of water through soil & rock to aquifers Surface movement down slopes to the sea

48 Human Impact on the Carbon Cycle: Fossil fuel use (Electricity & Transportation) Clearing forests Removes carbon-absorbing trees Burning trees puts out CO 2 *CO 2 is a greenhouse gas that traps heat in our atmosphere Crash Course Hydrologic & Carbon

49 Carbon Cycle CO 2 removed from atmosphere by photosynthesis & dissolved in ocean CO 2 released during aerobic respiration, decomposition, forest fires, deforestation, burning of fossil fuels, CH 4 released from livestock, landfills, rice paddies, swamps, fossil fuel production Major sink/reservoir: ocean, permafrost, limestone or sediments Carbon sequestering in ocean, peat bogs, plants, trees

50 Human Impact on the nitrogen cycle : Burning of fossil fuels releases nitric oxide (NO) makes NO 2 then makes HNO 3 (nitric acid; part of acid rain) Use of fertilizers adds nitrous oxide (N 2 O) to atmosphere through microbial action Agricultural processes remove nitrogen from topsoil Runoff of Fertilizer & manure adds excess nitrates to aquatic systems Causes eutrophication & algal blooms Results in oxygen depletion & biodiversity loss Creates Dead Zones; examples: Gulf of Mexico, Chesapeake Bay Estuary Can create Red Tide toxic algal bloom

51 *In proteins & nucleic acids *78% of air is N 2 Fixation: bacteria convert N 2 to NH 3 (ammonia) lightning converts N 2 to NO 3 - (nitrate) Nitrification: bacteria convert NH 4 + to NO 2 - (nitrite) to NO 3 - (Nitrate) * taken up by plants

52 Ammonification bacteria convert nitrogenous wastes & dead organisms back into NH 3 and NH 4 + Denitrification: Bacteria convert NO 3 - in soil back into N 2 or N 2 O (nitrous oxide)

53 Human Impact on the phosphorus cycle: Removing phosphate salts from mining Phosphate-rich runoff from fertilizer enters aquatic systems (esp. freshwater) & causes algal blooms (eutrophication) Y_8nRs Crash Course N & P

54 *Important for nucleic acids and energy transfer molecules (ATP) Does not include the atmosphere! Reservoir: rock & ocean bottoms Phosphorous Cycle phosphate in soil taken up by plants taken up by animals & returns to soil through decay

55 Human Impact on the sulfur cycle: Refining petroleum Combustion of coal Leads to acid precipitation (sulfuric acid) Smelting metallic ores (copper, lead, zinc) *Smelt: To melt (ores) in order to separate the metallic constituents. Bozeman biogeochemical cycles *All these processes release SO 2

56 Released in atmosphere by volcanoes, hot springs, soil decomposition, smelting, burning coal, & refining petroleum. In the air it is converted to sulfur dioxide (SO 2 ) is converted to sulfur trioxide gas (SO 3 ) & sulfuric acid (H 2 SO 4 ) & falls as acid rain Reservoirs: rocks & minerals & sulfate (SO 4 2- ) salts in ocean sediments