Presentation is loading. Please wait.

Presentation is loading. Please wait.

Ecosystems.

Similar presentations


Presentation on theme: "Ecosystems."— Presentation transcript:

1 Ecosystems

2 Studying organisms in their environment
biosphere ecosystem community population organism

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

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

7 Carbon cycle abiotic reservoir: CO2 in atmosphere enter food chain:
photosynthesis = carbon fixation in Calvin cycle recycle: return to abiotic: respiration combustion Carbon cycle CO2 in atmosphere Diffusion Respiration Photosynthesis Plants and algae Plants Animals Industry and home Combustion of fuels Carbonates in sediment Bicarbonates Deposition of dead material Deposition of dead material Fossil fuels (oil, gas, coal) Dissolved CO2

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

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

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

11 Remember transpiration?

12 Breaking the water cycle
Deforestation breaks the water cycle groundwater is not transpired to the atmosphere, so precipitation is not created 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 7800 acres
38 acre deforestation Hubbard Brook Experimental Forest 7800 acres

15 Effects of deforestation
40% increase in runoff loss of water 60x loss in nitrogen 10x loss in calcium loss into surface water 80 nitrate levels in runoff 40 loss out of ecosystem! of nitrate (mg/l ) Concentration 4 Deforestation 2 Why is nitrogen so important? 1965 1966 1967 1968 Year

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

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

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

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

20 Ecological pyramid sun Loss of energy between levels of food chain
can feed fewer animals in each level 1 100 100,000 1,000,000,000

21 What is your ecological footprint?!
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 Primary Production Amount of light energy converted to chemical energy (organic compounds) by autotrophs during a given time period in an ecosystem Gross primary production (GPP) Total primary production in ecosystem Amount of light energy converted to chemical energy by photosynthesis per unit of time Net primary production (NPP) Not all stored as organic molecules—some used for cellular respiration NPP = GPP-R Chemical energy available to next trophic level

23 Primary Production NPP expressed as
Energy per unit time (J/m2 · yr) Biomass added to ecosystem per unit area per unit time (g/m2 · yr) Usually expressed in terms of dry mass of organic material Amount of NEW biomass added Standing crop Total amount of biomass from photosynthetic autotrophs at a given time

24 TECHNIQUE 80 Snow Clouds 60 Vegetation Percent reflectance 40 Soil 20
Fig. 55-5 TECHNIQUE 80 Snow Clouds 60 Vegetation Percent reflectance 40 Soil 20 Liquid water 400 600 800 1,000 1,200 Visible Near-infrared Wavelength (nm)

25 Net primary production (kg carbon/m2·yr)
Fig. 55-6 Net primary production (kg carbon/m2·yr) 1 2 3

26 Primary Production in Aquatic Ecosystems
Limiting Resources Light ½ absorbed in top 15m of water Nutrients Usually nitrogen or phosphates Low in photic zone—being used by phytoplankton Increased concentration in areas of upwellings Eutrophication Rapid growth of primary producers in response to added nutrients Reduces oxygen concentration in water

27 Phytoplankton density (millions of cells per mL)
Fig. 55-7 EXPERIMENT Long Island Shinnecock Bay G F E C D Great South Bay B Moriches Bay A Atlantic Ocean RESULTS 30 Ammonium enriched 24 Phosphate enriched Unenriched control Phytoplankton density (millions of cells per mL) 18 12 6 A B C D E F G Collection site

28 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?

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


Download ppt "Ecosystems."

Similar presentations


Ads by Google