ECOSYSTEM ECOLOGY Energy Flow food chains Ecosystem The
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ECOSYSTEM ECOLOGY : Energy Flow, food chains
Ecosystem: • The organisms in a particular area and the physical environment with which they interact. • All the biotic and abiotic factors in a community. (Abiotic factors: energy, water, carbon, nitrogen, phosphorous)
An ecosystem has abiotic and biotic components: • ABIOTIC components: • Solar energy provides practically all the energy for ecosystems. • Inorganic substances, e. g. , sulfur, boron, tend to cycle through ecosystems.
• BIOTIC components: • The biotic components of an ecosystem can be classified according to their mode of energy acquisition. • In this type of classification, there are: • Autotrophs
Autotrophs • Autotrophs (=self-nourishing) are called primary producers. • Photoautotrophs fix energy from the sun and store it in complex organic compounds light • (= green plants, algae, some complex organic photoautotrophs bacteria) simple inorganic compounds
• Chemoautotrophs (chemosynthesizers) are bacteria • that oxidize reduced inorganic substances • (typically sulfur and ammonia compounds) • and produce complex organic compounds. oxygen reduced inorganic compounds chemoautotrophs complex organic compounds
Chemosynthesis near hydrothermal vents
Other chemoautotrophs: Nitrifying bacteria in the soil under our feet!
Heterotrophs • Heterotrophs (=other-nourishing) cannot produce their own food directly from sunlight+ inorganic compounds. They require energy previously stored in complex molecules. organic heterotrophs compounds (this may include several steps, with several different types of organisms) heat simple inorganic compounds
• Heterotrophs can be grouped as: • • consumers • decomposers
• Consumers feed on organisms or particulate organic matter. • Decomposers utilize complex compounds in dead protoplasm. • Bacteria and fungi are the main groups of decomposers. • Bacteria are the main feeders on animal material.
Fig. 55 -4 Tertiary consumers Microorganisms and other detritivores Detritus Secondary consumers Primary producers Heat Key Chemical cycling Energy flow Sun
Energy Flow through Ecosystems • Energy flows through ecosystems as organisms capture and store energy, then transfer it to organisms that eat them. • These organisms are grouped into trophic levels. . .
Trophic Levels: Route of energy flow - food chain - food web - pyramid of numbers
Pyramid of Numbers
Question: “Why are big fierce animals rare? ” Charles Elton, 1927
Answer: Because of the way energy flows through communities. . .
Ecosystem Energy Budgets: Primary Productivity (PP) Secondary Productivity (SP 1, SP 2)
Primary Productivity (PP) • Rate at which energy or biomass is produced per unit area by plants (primary producers) • Photosynthesis powers primary productivity. • The annual productivity of an area is determined primarily by sunlight, temperature, and moisture.
Distribution of Primary Production Worldwide Figure 56. 5
Positive Correlation Between Productivity and Sunlight
Positive Correlation Between Productivity and. . . Precipitation Temperature
Fig. 55 -8 Net primary production (g/m 2·yr) · 3, 000 Tropical forest 2, 000 Temperate forest 1, 000 Mountain coniferous forest Desert shrubland 0 Temperate grassland Arctic tundra 0 500 1, 000 Actual evapotranspiration (mm H 2 O/yr)
Secondary Productivity (SP 1, SP 2…) • rate of production of new biomass from PP by heterotrophic organisms (primary and secondary consumers) • positively correlated with rainfall. . .
Fig. 55 -10 Tertiary consumers Secondary consumers 10 J 100 J Primary consumers 1, 000 J Primary producers 10, 000 J 1, 000 J of sunlight
Where does all the energy go? ? ?
Fig. 55 -9 Plant material eaten by caterpillar 200 J 67 J Feces 100 J 33 J Growth (new biomass) Cellular respiration
Ecological Efficiency: Percent of energy transferred from one trophic level to the next.
Three categories of transfer efficiency are required to predict energy flow from PP to SP 1 to SP 2. . . 1) consumption efficiency 2) assimilation efficiency 3) production efficiency
1) consumption efficiency (CE) % of total productivity at one trophic level that is consumed by the next highest level (remainder not eaten)
Green World Hypothesis • Plants have many defenses against herbivores
2) assimilation efficiency (AE) % of ingested food energy that is assimilated (i. e. digested), and thus potentially available for growth, reproduction (remainder lost as feces)
Elephant dung
3) production efficiency (PE) % of assimilated energy that is incorporated into new biomass (growth, reproduction) (remainder lost as respiratory heat)
Implications? • SP 1 is the % of PP that is incorporated at the next highest trophic level. (Ditto for SP 2…) This is NEVER 100%. • Thus, energy loss at each trophic level limits the length of a food chain. . .
And that is why big fierce animals are rare!
Biogeochemical Cycles Nutrients exist in pools of chemical elements FOUR main reservoirs where these nutrients exist are: 1) Atmosphere - carbon in carbon dioxide, nitrogen in atmospheric nitrogen 2) Lithosphere - the rocks - phosphates, calcium in calcium carbonate, potassium in feldspar 3) Hydrosphere - the water of oceans, lakes, streams and soil - nitrogen in dissolved nitrate, carbon in carbonic acid
Atmosphere Living Organisms + Detritus Lithosphere Hydrosphere
4) Living Organisms and Nutrient Cycles • Living organisms are a reservoir in which carbon exists in carbohydrates (mainly cellulose) and fats, nitrogen in protein, and phosphorus in ATP
• In studying cycling of water, carbon, nitrogen, and other chemicals, ecologists focus on four factors: – Biological importance of each chemical – Major reservoirs for each chemical – Forms in which each chemical is available or used by organisms – Key processes driving movement of each chemical through its cycle
The Water Cycle • Water is essential to all organisms • 97% of the biosphere’s water is contained in the oceans, 2% is in glaciers and polar ice caps, and 1% is in lakes, rivers, and groundwater • Water moves by the processes of evaporation, transpiration, condensation, precipitation, and movement through surface and groundwater
The Carbon Cycle • Carbon-based organic molecules are essential to all organisms • Carbon reservoirs include fossil fuels, soils and sediments, solutes in oceans, plant and animal biomass, and the atmosphere • CO 2 is taken up via photosynthesis and released via respiration • Volcanoes and the burning of fossil fuels contribute CO 2 to the atmosphere
Fig. 55 -21 14. 9 390 14. 8 380 14. 7 CO 2 concentration (ppm) Temperature 14. 5 360 14. 4 14. 3 350 14. 2 340 14. 1 CO 2 330 14. 0 13. 9 320 13. 8 310 300 13. 7 13. 6 1960 1965 1970 1975 1980 1985 Year 1990 1995 2000 2005 Average global temperature (ºC) 14. 6 370
… and Global Temperature
The Nitrogen Cycle • Nitrogen is a component of amino acids, proteins, and nucleic acids • The main reservoir of nitrogen is the atmosphere (N 2) • N 2 is converted to NH 3 via nitrogen-fixing bacteria • Organic nitrogen is decomposed to NH 4+ by ammonification, and NH 4+ is decomposed to NO 3– by nitrifying bacteria; NH 4+ and NO 3– assimilated by plants • Denitrifying bacteria convert NO 3– back to N 2
How Bears Feed Salmon to the Forest • The run of salmon leads to a major flow of nutrients into estuaries and coastal watersheds
• Bears catch salmon in river and consume them in forest; on average, half the carcass is not eaten. • Bears’ fat tissue is virtually nitrogen-free, so most of nitrogen in salmon protein is excreted as urine and feces.
• Nitrogen 14 from atmosphere • Nitrogen 15 from salmon • Measurements of nitrogen isotope ratios in tree rings shows that nitrogen from salmon is incorporated into trees and enhances their growth
- Principles of ecology 2 flow of energy in an ecosystem
- Why does organism eat another organism
- Third level consumer
- The many overlapping food chains in an ecosystem
- Food chain producer
- Section 4 food chains and food webs
- Food chains, food webs and ecological pyramids
- Chaparral food chain
- How many food chains are there in the food web
- Food chain
- Regents biology food chains and energy in ecosystems
- Lab food chains and energy in ecosystems
- Calculate the efficiency of energy transfer
- 10 rule food chain
- Section 1 organisms and their relationships
- Chapter 2 section 1 organisms and their relationships
- How does energy flow in a food web
- Section 2 flow of energy in an ecosystem
- Energy flow and material cycling in ecosystem
- Energy flow and material cycling in ecosystem
- Energy flow in ecosystem
- Describe the flow of energy in the kelp forest ecosystem.
- Energy flow through an ecosystem is ----- *
- Energy roles in an ecosystem
- How does energy flow through an ecosystem
- Difference between ecosystem and ecology
- Ecosystem consists of
- Ecosystem ecology
- Ecology terms
- Difference between ecosystem and ecology
- Ecosystem ecology
- Ecosystem ecology
- Ecosystem ecology
- Ecology ecosystem
- Ecosystem ecology
- Rainforest food web
- Scavengers food chain
- A secondary consumer
- Food chains clipart
- Steps in food chain
- A model that shows how food chains overlap
- Are snakes secondary consumers
- A series of events in which one organism eats another
- The food chain of a lion
- Importance of food chains
- Which best summarizes the flow of energy in a producer
- Under the sea food chain
- Mountain lion food chain
- Food web def
- Food chain on land
- Tennessee food web
- Food chains in the savanna