AP Biology. Ecosystems

Transcription

1 Ecosystems

2 Studying organisms in their environment organism population community ecosystem biosphere

3 Essential questions What limits the production in ecosystems? How do nutrients move in the ecosystem? How does energy move through the ecosystem?

4 Ecosystem All the organisms in a community plus abiotic factors ecosystems are transformers of energy & processors of matter Ecosystems are self-sustaining what is needed? capture energy transfer energy cycle nutrients

5 Ecosystem inputs nutrients cycle constant energy flows input of through energy Matter Don t forget cannot be the created laws of or destroyed Physics! nutrients can only cycle biosphere inputs energy nutrients

6 Generalized Nutrient cycling consumers Decomposition connects all trophic levels consumers producers nutrients ENTER FOOD nutrients CHAIN = made made available available to producers to producers abiotic reservoir decomposers return to abiotic reservoir geologic processes

7 Carbon cycle CO 2 in atmosphere Diffusion Respiration abiotic reservoir: CO 2 in atmosphere enter food chain: Combustion photosynthesis of fuels = carbon fixation in Industry and home Calvin cycle Photosynthesis recycle: return to abiotic: Plants respiration Animals combustion Dissolved CO 2 Bicarbonates Photosynthesis Animals Plants and algae Deposition of dead material Carbonates in sediment Deposition of dead material Fossil fuels (oil, gas, coal)

8 Nitrogen cycle Carnivores abiotic reservoir: N in atmosphere enter food chain: nitrogen fixation by soil & aquatic bacteria recycle: decomposing & Herbivores nitrifying bacteria return to abiotic: denitrifying bacteria Atmospheric nitrogen Birds Plankton with nitrogen-fixing bacteria Fish loss to deep sediments excretion Death, excretion, feces Decomposing bacteria amino acids Ammonifying bacteria Nitrifying bacteria soil nitrates Plants Nitrogen-fixing bacteria (plant roots) Nitrogen-fixing bacteria (soil) Denitrifying bacteria

9 Phosphorus cycle Loss in drainage Plants Decomposers (bacteria & fungi) Phosphates in solution Land animals Soluble soil phosphate abiotic reservoir: rocks, minerals, soil enter food chain: erosion releases soluble phosphate uptake by plants recycle: decomposing bacteria Animal & fungi tissue Urine and feces return to abiotic: loss to Decomposers ocean sediment (bacteria and fungi) Rocks and minerals Animal tissue and feces Aquatic animals Plants and algae Precipitates Loss to deep sediment

10 Water cycle Water vapor Transpiration Precipitation Evaporation abiotic reservoir: surface & atmospheric water enter food chain: precipitation & plant uptake recycle: Solar energy transpiration return to abiotic: evaporation & runoff Runoff Oceans Lakes Percolation in soil Groundwater Aquifer

11 Transpiration Remember transpiration?

12 Breaking the water cycle Deforestation breaks the water cycle groundwater is not transpired to the atmosphere, so precipitation is not created QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture. forest desert desertification

13 Repairing the damage The Greenbelt Movement planting trees in Kenya restoring a sustainable ecosystem establishing democracy empowering women Wangari Maathai Nobel Peace prize 2004

14 Studying ecosystems Hubbard Brook Experimental Forest 38 acre deforestation 7800 acres

15 Concentration of nitrate (mg/l ) Effects of deforestation 40% increase in runoff loss of water 60x loss in nitrogen 10x loss in calcium 80 nitrate levels in runoff loss into surface water Deforestation loss out of ecosystem! Why is nitrogen so important? Year

16 Ecosystem inputs nutrients cycle energy flows through biosphere inputs energy nutrients

17 Energy flows through ecosystems sun secondary consumers (carnivores) loss of energy primary consumers (herbivores) loss of energy producers (plants)

18 Food chains Trophic levels feeding relationships start with energy from the sun captured by plants 1 st level of all food chains food chains usually go up only 4 or 5 levels inefficiency of energy transfer all levels connect to decomposers Level 4 Tertiary consumer top carnivore Level 3 Secondary consumer Level 2 Primary consumer Level 1 Producer Decomposers carnivore heterotrophs herbivore autotrophs Bacteria sun Fungi

19 Inefficiency of energy transfer Loss of energy between levels of food chain To where is the energy lost? The cost of living! sun 17% growth only this energy moves on to the next level in the food chain 33% cellular respiration 50% waste (feces) energy lost to daily living

20 Ecological pyramid Loss of energy between levels of food chain can feed fewer animals in each level 1 sun ,000 1,000,000,000

21 Humans in food chains Dynamics of energy through ecosystems have important implications for human populations how much energy does it take to feed a human? if we are meat eaters? if we are vegetarian? What is your ecological footprint?!

22 Food webs Food chains are linked together into food webs Who eats whom? a species may weave into web at more than one level bears humans eating meat? eating plants?

23 Any Questions?? We re working on a lot of them!