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The Flow of Energy Through Ecosystems. Heat Energy (Lower Energy, Longwave ). Input Energy (Higher Energy, Shortwave). Work Energy (Higher – Lower Energy). Energy Conversion Process (Physical or Chemical). Dr. Jeffrey R. Corney, Managing Director
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The Flow of Energy Through Ecosystems Heat Energy (Lower Energy, Longwave) Input Energy (Higher Energy, Shortwave) Work Energy (Higher – Lower Energy) Energy Conversion Process (Physical or Chemical) Dr. Jeffrey R. Corney, Managing Director of the University of Minnesota’s Cedar Creek Ecosystem Science Reserve
Key to Productivity: Energy & Water (…and Nutrients) Wikipedia Annual Mean Solar Energy Intercepting Surface of Earth NASA
Eco-Regions of Earth LAND OCEAN
Total Global Net Productivity Ecosystem Type Open Ocean Tropical Rain Forest Temperate Deciduous Forest Savanna Boreal Coniferous Forest Continental Shelf Agricultural Land Temperate Grassland Woodland & Shrubland Estuaries Swamps & Marshes Desert Scrub Lakes & Streams Tundra (arctic & alpine) Extreme Desert per R.H. Whittaker Average Global Net Primary Productivity (billion kcal/yr)
Global Net Productivity per Unit Area Ecosystem Type Estuaries Swamps & Marshes Tropical Rain Forest Temperate Deciduous Forest Boreal Coniferous Forest Savanna Agricultural Land Woodland & Shrubland Temperate Grassland Lakes & Streams Continental Shelf Tundra (arctic & alpine) Open Ocean Desert Scrub Extreme Desert per R.H. Whittaker Average Net Primary Productivity (kcal/m2/yr)
THE BIG IDEA: Solar Energy… How Stuff Works …Builds Organisms, Powers Life Functions, and Drives Earth’s Water, Carbon, Oxygen & Nutrient Cycles
Energy Flow Food “Chain” vs. “Food Web” Science Bob
Energy Flow Trophic Levels
Energy Flow Trophic Levels as “Food Web”
Energy Flow Trophic Level Pyramids
Energy Flow Trophic Pyramid to Eltonian Energy Transfer Pyramid U of Virginia The starting point is PHOTOSYNTHESIS
Energy Flow Photosynthesis Cellular Level World Book Encyclopedia
Energy Flow Photosynthesis in Chloroplasts
Energy Flow Site of Photosynthesis: Chlorophyll
Energy Flow The Calvin Cycle The Simple Home School
Energy Flow Product of Photosynthesis
Energy Flow Transfer of Energy from Sun to Cell From here… …to here!
Energy Flow Biological Energy Storage & Release Photosynthesis ENERGY (in) + 6CO2 + 6H2OC6H12O6 + 6O2 “Sugar” Solar Energy > ATP Aerobic Respiration C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY (out) “Sugar” Chemical Energy > ATP J. Corney
Conversion of Photon Energy to Work Heat Energy (Lower Energy, Longwave) Input Energy (Higher Energy, Shortwave) Work Energy (Higher – Lower Energy) Energy Conversion Process (Physical or Chemical)
Where It All Begins… NOTE: 1 Watt = 1 Joule/second 1 Joule = 0.00024 kcal 1kcal = 1 Calorie The Sun Radiates 63,000,000 W/m2 of Energy from Its Surface into Space
Then, On to Earth… (93 Million Miles in about 8 Minutes) 1,367 W/m2 or 0.002% of the Sun’s Total Energy Output Reaches Earth’s Orbit
Earth’s Sphere Intercepting Energy 343 W/m2 or 0.0005% of the Sun’s Total Energy Output Enters Earth’s Atmosphere
Earth’s Gross Solar Insolation Wikipedia Annual Mean Solar Insolation Intercepting Top of Earth’s Atmosphere
Earth’s Energy Budget 49% Reflected 51% Re-Radiated 51% Absorbed Jason Project 175 W/m2 or 0.00025% of the Sun’s Total Energy Output Is Absorbed by Earth’s Surface
Energy Flow Solar Spectrum Reaching Earth Sun High energy, short wavelength Low energy, long wavelength Nonionizing radiation Ionizing radiation 343 W/m2 343 W/m2 Cosmic rays Gamma rays X rays Far ultraviolet waves Near ultraviolet waves Visible waves Near infrared waves Far infrared waves microwaves TV waves Radio waves REACHING EARTH LEAVING EARTH 10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1 Wavelength in meters (not to scale) 10% 50% 40% 175 W/m2 ABSORBED BY EARTH’S SURFACE 103 W/m2 REFLECTED BY ATMOSPHERE & SURFACE 65 W/m2 ABSORBED BY ATMOSPHERE & CLOUDS
Net Solar Insolation at Surface Wikipedia Annual Mean Solar Insolation Intercepting Surface of Earth
Energy Flow Photosynthetically Active Radiation (PAR) Sun High energy, short wavelength Low energy, long wavelength Nonionizing radiation Ionizing radiation REACHING EARTH LEAVING EARTH Cosmic rays Gamma rays X rays Far ultraviolet waves Near ultraviolet waves Visible waves Near infrared waves Far infrared waves microwaves TV waves Radio waves 10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1 10% 50% 40% Wavelength in meters (not to scale) AVAILABLE FOR PHOTOSYNTHESIS (PAR) Global Annual Avg. = 70W/m2 [0.0001% of Total Solar Energy Output] Range (latitude/season) = 0 - 240W/m2 [e.g. = mid-lat./summer = 160W/m2]
Energy Flow Cross-Section of Energy for 1-m2 (4-month Summer Growing Season)* Average PAR during Summer at 43oN = 160 W/m2 1 Watt = 1 Joule/second 1 Joule = 0.00024 kcal 1 kcal = 1 Calorie 160 W/m2 160 W/m2 160 W/m2 160 W/m2 0.04 kcal/sec/m2 *Over a four-month summer season in a Temperate Deciduous Forest at 43oN Latitude (generalized from Hubbard Brook Experimental Forest study) J. Corney
Energy Flow Energy Flow Into an Ecosystem 400,000 kcal/m2 * (Summer Avg. = 160 W/m2) SOLAR ENERGY POTENTIALLY AVAILABLE FOR PHOTOSYNTHESIS *Over a four-month summer season in a Temperate Deciduous Forest at 43oN Latitude (generalized from Hubbard Brook Experimental Forest study) 390,000 kcal/m2 Absorbed by Earth and re-radiated as heat J. Corney
Energy Flow Energy Flow Through an Ecosystem ECOSYSTEM 6,000 PRODUCERS 700 10,000 kcal/m2 1,000 CONSUMERS 10,000 kcal/m2 70 100 10 7 1o 2o 3o 200 20 3 3,000 DECOMPOSERS 3,223 SOLAR ENERGY HEAT ENERGY J. Corney
Energy Flow Energy Flow Through a Trophic Level AVAILABLE from PRODUCERS 1,000 kcal (from ~1,000 plants/m2) CONSUMED by PRIMARY CONSUMERS (1o) (for ~100 grasshoppers/m2) 10 kcal 2 kcal 7 kcal Feces HEAT Respiration 1 kcal AVAILABLE for SECONDARY CONSUMERS (2o) 1 kcal X 100 grasshoppers = 100 kcal (for ~10 birds/m2) DECOMPOSERS Growth J. Corney
Energy Flow Primary Productivity Gross Primary Productivity (GPP) uses available (PAR) Solar Energy, Water, and Carbon Dioxide to produce Glucose Range = 0.01% - 5% of PAR (2.5% average) [~ 0.00000005% of Total Solar Output] Mr. G’s Net Primary Productivity (NPP)= Glucose produced during photosynthesis (GPP) – Glucose used during plant Respiration (R) Range = 20% – 60% of GPP (40% average) Mr. G’s
Energy Flow Secondary Productivity GSP ranges from 20% to 90% of Incoming Food Energy Mr. G’s NSP ranges from 1% to 40% of Incoming Food Energy Mr. G’s
Energy Flow Efficiency of Energy Transfer INGESTION EFFICIENCY: Energy Consumed as Food Herbivores = 5% - 50% (25% average) Carnivores = 25% - 100% (60% average) ASSIMILATION EFFICIENCY: Energy Digested & Absorbed (- feces) Herbivores = 20% - 50% (30% average) Carnivores = 70% - 90% (80% average) PRODUCTION EFFICIENCY: Energy Used to Grow Biomass Invertebrates = 30% - 40% (35% average) Vertebrates: Ectotherms = 5% - 15% (10% average) Vertebrates: Endotherms = 1% - 2% (1.5% average) TROPHIC-LEVEL ENERGY TRANSFER EFFICIENCY: Available for Next Consumer Trophic-Level Energy Transfers = 2% - 24% (10% average) > “The 10% Rule”
Energy Flow Energy Transfer Eltonian Pyramid Tertiary Consumers 0.010% of GPP available 0.0025% of PAR Secondary Consumers 0.10% of GPP available 0.025% of PAR Primary Consumers 10% of GPP available 0.25% of PAR Net Primary Productivity (NPP) = 1.0% of PAR or 40% of GPP Primary Producers Gross Primary Productivity (GPP) = 2.5% of PAR Solar Energy Available for Photosynthesis (PAR) = 100%* *Photosynthetically Active Radiation (PAR) = 40% of Net Surface Solar Insolation J. Corney
Energy Flow Example from Actual Temperate Forest McGraw Hill
Energy Flow Example from a Sub-tropical Ecosystem Wadsworth Click and Learn Pearson
Energy Flow Examples from Other Ecosystems Mr. G’s Mr. G’s
Energy Flow Examples of Actual Efficiencies SIDE BAR A Human at Rest Uses… 1,200 Calories/day or 5,000,000 Joules/day or 60 Joules/second …just for Respiration! McGraw Hill
Nutrient Cycling Then There’s the Carbon Cycle… Animals & Dead Material Dept. of Energy
Nutrient Cycling ECOSYSTEM Carbon Cycling Through an Ecosystem CO2 CO2 OTHER SOURCES CONSUMERS C6H12O6 PRODUCERS CO2 1o 2o 3o DECOMPOSERS C6H12O6 SOIL “SINK” J. Corney
Nutrient Cycling Energy Flow & Carbon Cycling J. Corney
For Next Time… Nitrogen Cycle Linked to Carbon Cycle Dept. of Energy Wikipedia WHAT’S GOING ON IN THE SOIL?
Dr. Jeffrey R. Corney, Managing Director University of Minnesota Cedar Creek Ecosystem Science Reserve 2660 Fawn Lake Dr NE East Bethel, MN 55005 (763) 434-5131 www.cedarcreek.umn.edu jcorney@umn.edu
Trophic-Level Energy Transfer Eltonian Pyramid Decomposers Tertiary Consumers Secondary Consumers Primary Consumers Primary Producers Solar Energy Available for Photosynthesis (PAR) J. Corney
ENERGY FLOW PRODUCERS CONSUMERS 1o 2o 3o DECOMPOSERS SOLAR ENERGY HEAT ENERGY J. Corney
ENERGY FLOW 6,000 PRODUCERS 700 CONSUMERS 1,000 10,000 kcal/m2 10,000 kcal/m2 70 100 10 7 1o 2o 3o 200 20 3 3,000 DECOMPOSERS SOLAR ENERGY 3,223 HEAT ENERGY J. Corney
CARBON CYCLE CO2 CO2 OTHER SOURCES CONSUMERS C6H12O6 PRODUCERS CO2 1o 2o 3o ATMOSPHERE DECOMPOSERS C6H12O6 SOIL “SINK” J. Corney