Ecosystems: Components, Energy Flow, and Matter Cycling

1. Ecosystems: Components, Energy Flow, and Matter Cycling “All things come from earth, and to earth they all return”—Menander

2. Ecology and the levels of organization of matter • Ecology—Greek oikos meaning house • Study of how organisms interact with one another and their non-living environment (biotic and abiotic components) • Studies connections in nature on the thin life supporting membrane of air, water, and soil • Levels of Organization of Matter • Subatomic to biosphere

3. Biosphere Biosphere Ecosystems Communities Populations Organisms Ecosystem Organization • Organisms • Made of cells • Eukaryotic vs Prokaryotic • Species • Groups of organisms that resemble one another in appearance, behavior, and genetic make up • Sexual vs Asexual reproduction • Production of viable offspring in nature • 1.5 million named; 10-14 million likely • Populations • Genetic diversity • Communities • Ecosystems • Biosphere Fig. 4.2, p. 66

4. Atmosphere Biosphere Vegetation and animals Soil Crust Rock core Lithosphere Mantle Crust (soil and rock) Crust Biosphere (Living and dead organisms) Atmosphere (air) Hydrosphere (water) Lithosphere (crust, top of upper mantle) Earth’s Life Support Systems • Troposphere • To 11 miles • Air is here • Stratosphere • 11 to 30 miles • Ozone layer • Hydrosphere • Solid, liquid, and gaseous water • Lithosphere • Crust and upper mantle • Contains non-renewable res.

5. Biosphere Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Oxygen cycle Heat in the environment Heat Heat Heat Sustaining Life on Earth… • One way flow of high quality energy • The cycling of matter (the earth is a closed system) • Gravity • Causes downward movement of matter

6. Abiotic Components Water, air, temperature, soil, light levels, precipitation, salinity Sets tolerance limits for populations and communities Some are limiting factors that structure the abundance of populations Biotic Components Producers, consumers, decomposers Plants, animals, bacteria/fungi Biotic interactions with biotic components include predation, competition, symbiosis, parasitism, commensalism etc. Major Ecosystem Components

7. Terrestrial Sunlight Temperature Precipitation Soil nutrients Fire frequency Wind Latitude Altitude Aquatic/Marine Light penetration Water clarity Water currents Dissolved nutrient concentrations Esp. N, P, Fe Dissolved Oxygen concentration Salinity Limiting Factors on Land & in H2O

8. Energy in = Energy out Solar radiation Reflected by atmosphere (34%) Radiated by atmosphere as heat (66%) UV radiation Lower Stratosphere (ozone layer) Visible light Greenhouse effect Troposphere Absorbed by ozone Heat Absorbed by the earth Heat radiated by the earth Earth The Source of High Quality Energy • Energy of sun lights and warms the planet • Supports PSN • Powers the cycling of matter • Drives climate and weather that distribute heat and H2O

9. Fate of Solar Energy… • Earth gets 1/billionth of sun’s output of energy • 34% is reflected away by atmosphere • 66% is absorbed by chemicals in atmosphere = re-radiated into space • Visible light, Infrared radiation (heat), and a small amount of UV not absorbed by ozone reaches the atmosphere • Energy warms troposphere and land • Evaporates water and cycles it along with gravity • Generates winds • A tiny fraction is captured by photosynthesizing organisms • Natural greenhouse effect vs. Global Warming

10. Primary Productivity • The conversion of light energy to chemical energy is called “gross primary production.” • Plants use the energy captured in photosynthesis for maintenance and growth. • The energy that is accumulated in plant biomass is called “net primary production.”

11. To sustain life on _____ of energy and ____ of matter. A.) one way flow, cycling B.) one way flow, one way flow C.) cycling, cycling D.) cycling, one way flow E.) nothing

12. The layer containing ozone is called: A.) troposphere B.) lithosphere C.) stratosphere D.) hydrosphere E.) mesosphere

13. Ecology is the study of how _____ interact: A.) communities B.) organisms C.) ecosystems D.) people E.) animals

14. Primary Productivity • NPP=GPP-respiration rate • GPP= RATE at which producers convert solar energy into chemical energy as biomass • Rate at which producers use photosynthesis to fix inorganic carbon into the organic carbon of their tissues • These producers must use some of the total biomass they produce for their own respiration • NPP= Rate at which energy for use by consumers is stored in new biomass (available to consumers) • Units Kcal/m2/yr or g/m2/yr • How do you measure it? AP Lab Site • Most productive vs. least productive

15. Estuaries Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest (taiga) Savanna Agricultural land Woodland and shrubland Temperate grassland Lakes and streams Continental shelf Open ocean Tundra (arctic and alpine) Desert scrub Extreme desert 800 1,600 2,400 3,200 4,000 4,800 5,600 6,400 7,200 8,000 8,800 9,600 Average net primary productivity (kcal/m2/yr) What are the most productive Ecosystems?

16. Fate of Primary Productivity and Some important questions… • Since producers are ultimate source of all food, why shouldn’t we just harvest the plants of the world’s marshes? • Why don’t we clear cut tropical rainforests to grow crops for humans? • Why not harvest primary producers of the world’s vast oceans? • Vitousek et al: Humans now use, waste, or destroy about 27% of earth’s total potential NPP and 40% of the NPP of the planet’s terrestrial ecosystems

17. Heat Heat Abiotic chemicals (carbon dioxide, oxygen, nitrogen, minerals) Solar energy Heat Decomposers (bacteria, fungus) Producers (plants) Consumers (herbivores, carnivores) Heat Heat Biotic Components of Ecosystems • Producers (autotrophs) • Source of all food • Photosynthesis • Consumers=heterotroph • Aerobic respiration • Anaerobic respiration • Methane, H2S • Decomposers • Matter recyclers… • Release organic compounds into soil and water where they can be used by producers

18. TrophicLevels • Each organism in an ecosystem is assigned to a feeding (or Trophic) level • Primary Producers • Primary Consumers (herbivores) • Secondary Consumer (carnivores) • Tertiary Consumers • Omnivores • Detritus feeders and scavengers • Directly consume tiny fragments of dead stuff • Decomposers • Digest complex organic chemicals into inorganic nutrients that are used by producers • Complete the cycle of matter

19. Detritus feeders Decomposers Termite and carpenter ant work Carpenter ant galleries Bark beetle engraving Long-horned beetle holes Dry rot fungus Mushroom Wood reduced to powder Powder broken down by decomposers into plant nutrients in soil Time progression Fig. 4.15, p. 75 Detritivores vs Decomposers stop

20. First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Producers (plants) Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Heat Heat Heat Heat Solar energy Heat Heat Heat Detritvores (decomposers and detritus feeders) Energy Flow and Matter Cycling in Ecosystems… • Food Chains vs. Food Webs • KEY: There is little if no matter waste in natural ecosystems!

21. Humans Blue whale Sperm whale Killer whale Elephant seal Crabeater seal Leopard seal Emperor penguin Adélie penguins Petrel Squid Fish Carnivorous plankton Herbivorous zooplankton Krill Fig. 4.18, p. 77 Phytoplankton Generalized Food Web of the Antarctic Note: Arrows Go in direction Of energy flow…

22. Food Webs and the Laws of matter and energy • Food chains/webs show how matter and energy move from one organism to another through an ecosystem • Each trophic level contains a certain amount of biomass (dry weight of all organic matter) • Chemical energy stored in biomass is transferred from one trophic level to the next • With each trophic transfer, some usable energy is degraded and lost to the environment as low quality heat • Thus, only a small portion of what is eaten and digested is actually converted into an organisms’ bodily material or biomass (WHAT LAW ACCOUNTS FOR THIS?)

23. Food Webs and the Laws of matter and energy • Food chains/webs show how matter and energy move from one organism to another through an ecosystem • Each trophic level contains a certain amount of biomass (dry weight of all organic matter) • Chemical energy stored in biomass is transferred from one trophic level to the next • With each trophic transfer, some usable energy is degraded and lost to the environment as low quality heat • Thus, only a small portion of what is eaten and digested is actually converted into an organisms’ bodily material or biomass (WHAT LAW ACCOUNTS FOR THIS?) • Ecological Efficiency: • The % of usable nrg transferred as biomass from one trophic level to the next (ranges from 5-20% in most ecosystems, use 10% as a rule of thumb) • Thus, the more trophic levels or steps in a food chain, the greater the cumulative loss of useable energy…

24. Food Webs and the Laws of matter and energy • Ecological Efficiency: • The % of usable energy transferred as biomass from one trophic level to the next (ranges from 5-20% in most ecosystems, use 10% as a rule of thumb) • Thus, the more trophic levels or steps in a food chain, the greater the cumulative loss of useable energy…

25. Heat Heat Heat Tertiary consumers (human) Decomposers 10 Secondary consumers (perch) Heat 100 Primary consumers (zooplankton) 1,000 Heat 10,000 Usable energy Available at Each tropic level (in kilocalories) Producers (phytoplankton) Pyramids of Energy and Matter • Pyramid of Energy Flow • Pyramid of Biomass

26. Which of the following is the most productive ecosystem per meter squared? A.) desert B.) open ocean C.) estuaries D.) tundra E.) rainforest

27. Which of the following is the most productive ecosystem? A.) desert B.) open ocean C.) estuaries D.) tundra E.) rainforest

28. What is the usual percentage of ecological efficiency? A.) 2% B.) 20% C.) 15% D.) 10% E.)30%

29. Which trophic level makes its own food from sunlight? A.) primary producers B.) primary consumers C.) secondary consumers D.) tertiary consumers E.) decomposers

30. Ecological Pyramids of Energy

31. Ecological Pyramids of Biomass

32. Implications of Pyramids…. • Why could the earth support more people if the eat at lower trophic levels? • Why are food chains and webs rarely more than four or five trophic levels? • Why do marine food webs have greater ecological efficiency and therefore more trophic levels than terrestrial ones? • Why are there so few top level carnivores? • Why are these species usually the first to suffer when the the ecosystems that support them are disrupted?

33. Solar Capital Air resources and purification Climate control Recycling vital chemicals Water resources and purification Renewable energy resources Soil formation and renewal Nonrenewable energy resources Natural Capital Waste removal and detoxification Nonrenewable mineral resources Natural pest and disease control Potentially renewable matter resources Biodiversity and gene pool Ecosystem Services and Sustainability Lessons From Nature! • Use Renewable Solar Energy As Energy Source • Recycle the chemical nutrients needed for life

34. Matter Cycles • You are responsible for knowing the water, carbon, nitrogen, sulfur, and phosphorus cycles • Know major sources and sinks • Know major flows • Know how human activities are disrupting these cycles

35. Carbon Cycle

36. Nitrogen Cycle

37. Zonation in Lakes

38. Thermal Stratification in Lakes

39. ____ is the absorption of nitrogen into plants through the soil. A.) nitrogen fixation B.) assimilation C.) nitrification D.) denitrification E.) ammonification

40. Which of the following processes produce a product that is toxic to the plants? A.) nitrogen fixation B.) assimilation C.) nitrification D.) denitrification E.) ammonification

41. Which of the following processes makes the nitrogen product usable by the plant? A.) nitrogen fixation B.) assimilation C.) nitrification D.) denitrification E.) ammonification

42. Which trophic level has the highest amount of biomass? A.) tertiary consumers B.) zooplankton C.) phytoplankton D.) primary producers E.) primary consumers

43. What is the deepest zone in a lake? A.) benthic zone B.) bathayal zone C.) abyssal zone D.) euphotic zone E.) limnetic zone

45. Soils: Formation Immature soil O horizon Leaf litter A horizon Topsoil Regolith B horizon Subsoil Bedrock C horizon Parent material Young soil Mature soil • Soil profile • Humus • Soil horizons Fig. 10.12, p. 220

46. Soil Properties Fig. 10.17, p. 224 Water Water 100%clay High permeability Low permeability 0 80 20 Increasing percentage clay Increasing percentage silt 60 40 40 60 20 80 0 80 60 40 20 100%sand 100%silt Increasing percentage sand • Infiltration • Leaching • Porosity/permeability • Texture • Structure • pH Fig. 10.16, p. 224

47. Soil Quality Texture Nutrient Infiltration Water-Holding Aeration Tilth Capacity Capacity Clay Good Poor Good Poor Poor Silt Medium Medium Medium Medium Medium Sand Poor Good Poor Good Good Loam Medium Medium Medium Medium Medium Fig. 10.15b, p. 223

48. Soil Chemistry • Acidity / Alkalinity – pH • Major Nutrients • Nitrogen • Phosphorus (phosphates) • Potassium (potash)

49. Acidity / Alkalinity – pH • Proper pH directly affects the availability of plant food nutrients • Soil is best if between pH 6 – 8 (except for certain acid loving plants) • ‘Sour’ if too acidic • ‘Sweet’ if too basic

50. Acidity / Alkalinity – pH • Too acidic or basic will not • Allow compounds to dissolve • Allow presence of certain ions • If soil is too acidic, add ground limestone • If soil is too basic, add organic material like steer manure