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Sun Heat Primary producers Primary consumers Detritus Secondary and tertiary consumers Microorganisms and other detritivores Key Chemical cycling Energy flow 4

© 2014 Pearson Education, Inc. 5 Measures of Production GPP: Gross Primary Production (energy converted to chemical energy of organic compounds in a given amount of time) NPP: Net Primary Production (includes only GPP not used for respiration in the producers) NPP = GPP – R a NEP: Net Ecosystem Production (total accumulation of biomass) NEP = GPP – R T

© 2014 Pearson Education, Inc. Technique Snow Clouds Vegetation Soil Liquid water Percent reflectance Wavelength (nm) VisibleNear-infrared ,0001,

© 2014 Pearson Education, Inc. Net primary production (kg carbon/m 2 yr)

© 2014 Pearson Education, Inc. Results Ammonium enriched Phosphate enriched Unenriched control Collection site ABCDEFG Phytoplankton density (millions of cells per mL) 8

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1,400 1,200 1, Mean annual precipitation (cm) Net annual primary production (above ground, dry g/m 2 yr) 10

© 2014 Pearson Education, Inc. Plant material eaten by caterpillar Cellular respiration Growth (new biomass; secondary production) Not assimilated Feces 100 J 200 J 33 J 67 J Assimilated 11

© 2014 Pearson Education, Inc. Tertiary consumers Secondary consumers Primary consumers Primary producers 10 J 100 J 1,000 J 10,000 J 1,000,000 J of sunlight 12

© 2014 Pearson Education, Inc. Trophic level Tertiary consumers Secondary consumers Primary consumers Primary producers (a) Most ecosystems (data from a Florida bog) (b) Some aquatic ecosystems (data from the English Channel) Trophic level Dry mass (g/m 2 ) Dry mass (g/m 2 ) Primary consumers (zooplankton) Primary producers (phytoplankton) 13

© 2014 Pearson Education, Inc. Experiment Ecosystem type Arctic Subarctic Boreal Temperate Grassland Mountain A Results G M T S U N H,I L B,C E,F K D P O J R Q P U T R Q S O K J N M L I H G E B A C D F −15−10−5− Mean annual temperature (°C) Percent of mass lost 14

© 2014 Pearson Education, Inc. Movement over land by wind Precipitation over land Percolation through soil Evaporation from ocean Evapotranspiration from land Precipitation over ocean Runoff and groundwater The water cycle 15

© 2014 Pearson Education, Inc. Consumers Decomposition Photosynthesis Cellular respiration Photo- synthesis Phyto- plankton CO 2 in atmosphere Burning of fossil fuels and wood The carbon cycle 16

© 2014 Pearson Education, Inc. The nitrogen cycle Fixation Denitrification Runoff N fertilizers Reactive N gases Industrial fixation N 2 in atmosphere NO 3 − NH 4  Dissolved organic N NO 3 − Aquatic cycling Decomposition and sedimentation Terrestrial cycling Fixation in root nodules Decom- position N2N2 NO 3 − NH 4  Ammoni- fication Assimilation Denitri- fication Uptake of amino acids Nitrification 17

© 2014 Pearson Education, Inc. Wind-blown dust Geologic uplift Weathering of rocks Decomposition PlanktonDissolved Uptake Leaching Decomposition Consumption Runoff PO 4 3− Plant uptake of PO 4 3− Sedimentation The phosphorus cycle 18

© 2014 Pearson Education, Inc. Concrete dam and weir (b) Clear-cut watershed (a) (c) Nitrate in runoff from watersheds Deforested Control Completion of tree cutting Nitrate concentration in runoff (mg/L) 19

© 2014 Pearson Education, Inc. (a) In 1991, before restoration In 2000, near the completion of restoration (b) 20

© 2014 Pearson Education, Inc. Decrease in concentration of soluble uranium in groundwater (b)Wastes containing uranium, Oak Ridge National Laboratory (a) Days after adding ethanol Concentration of soluble uranium (  M) 21