Ecosystems Studying organisms in their environment organism population

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Ecosystems

Ecosystems

Studying organisms in their environment organism population community ecosystem biosphere

Studying organisms in their environment organism population community ecosystem biosphere

Essential Questions: § What limits the production in ecosystems? § How do nutrients move

Essential Questions: § What limits the production in ecosystems? § How do nutrients move in the ecosystem? § How does energy move through the ecosystem?

Ecosystem § All the organisms in a community plus abiotic factors u ecosystems are

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

Ecosystem inputs constant energy flows input of through energy nutrients cycle Matter cannot Don’t

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

Generalized Nutrient cycling consumers producers consumers decomposers nutrients ENTER FOOD CHAIN made available =

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

Carbon cycle CO 2 in atmosphere Combustion of fuels Industry and home Diffusion Respiration

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

Nitrogen cycle abiotic reservoir: § N in atmosphere enter food chain: § nitrogen fixation

Nitrogen cycle 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 excretion Decomposing bacteria amino acids Ammonifying bacteria loss to deep sediments Nitrifying bacteria soil nitrates Nitrogen-fixing bacteria (plant roots) Nitrogen-fixing bacteria (soil) Denitrifying bacteria

abiotic reservoir: § rocks, minerals, soil enter food chain: § erosion releases soluble phosphate

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 Plants Land animals Soluble soil phosphate Loss in drainage Decomposers (bacteria and fungi) Rocks and minerals Decomposers Phosphates (bacteria & fungi) in solution Animal tissue and feces Animal tissue Urine and feces Aquatic animals Plants and algae Precipitates Loss to deep sediment

abiotic reservoir: § surface & atmospheric water enter food chain: § precipitation & plant

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 Groundwater Aquifer

Transpiration Why does water flow into, up and out of a plant? We will

Transpiration Why does water flow into, up and out of a plant? We will discuss process in detail soon!

Breaking the water cycle § Deforestation breaks the water cycle u groundwater is not

Breaking the water cycle § Deforestation breaks the water cycle u groundwater is not transpired to the atmosphere, so precipitation is not created forest desertification

Effects of deforestation 40% increase in runoff loss of water loss into surface water

Effects of deforestation 40% increase in runoff loss of water loss into surface water 80 nitrate levels in runoff Concentration of nitrate (mg/l ) u § 60 x loss in nitrogen § 10 x loss in calcium 40 loss out of ecosystem! 4 2 Why is 0 nitrogen 1965 so important? Deforestation 1966 1967 Year 1968

Energy flows through ecosystems sun Energy is incorporated into a community by what group?

Energy flows through ecosystems sun Energy is incorporated into a community by what group? secondary consumers (carnivores) primary consumers (herbivores) producers (plants) loss of energy

Productivity § Primary productivity: Term for the rate which producers photosynthesize organic compounds in

Productivity § Primary productivity: Term for the rate which producers photosynthesize organic compounds in an ecosystem. u u Gross primary productivity: total amount of photosynthetic biomass production in an ecosystem Net Primary Productivity = GPP – respiration cost

§ Ecosystems with greater productivity are more stable and diverse than ecosystems with less

§ Ecosystems with greater productivity are more stable and diverse than ecosystems with less productivity. u Which ecosystems are most productive?

Inefficiency of energy transfer § sun Loss of energy between levels of food chain

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

Food chains § Trophic levels feeding relationships u start with energy from the sun

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

Producers & Decomposers § Producers move matter from abiotic sources (air/soil) to biotic sources

Producers & Decomposers § Producers move matter from abiotic sources (air/soil) to biotic sources (food web) § Decomposers move matter from biotic sources to abiotic sources

sun Ecological pyramid § Loss of energy between levels of food chain u can

sun Ecological pyramid § Loss of energy between levels of food chain u can feed fewer animals in each level 10% energy available for next level Notice only 1% of sunlight energy converted by plants

Humans in food chains § Dynamics of energy through ecosystems have important implications for

Humans in food chains § Dynamics of energy through ecosystems have important implications for human populations u how much energy does it take to feed a human? § if we are meat eaters? § if we are vegetarian?

What you need to be able to do: § Using the laws of conservation

What you need to be able to do: § Using the laws of conservation of matter and energy to do some basic accounting and determine different aspects of energy and matter usage in a community. § Remember: Inputs have to equal outputs

Sample problem § A caterpillar consumes 100 kcal of energy. It uses 35 kcal

Sample problem § A caterpillar consumes 100 kcal of energy. It uses 35 kcal for cell respiration, and loses 50 kcal as waste. Determine the trophic efficiency for its creation of new biomass. Total energy = 100 kcal u Lost and Respired: 35 + 50 = 85 kcal u Total energy for growth: 15 kcal u § Efficiency = part/total = 15/100 =. 15 (or 15% or 3/20 as fraction)