Ecosystem Ecology II: Global Carbon Cycle PDF

Ecosystem Ecology II: The Global Carbon Cycle (feat: P) etc. Please don’t forget to do your evaluations! Ecology in the News Warming is melting permafrost CO2 Methane Ecology in the News Phosphorus: key element in constructing lipid membranes and...

Ecosystem Ecology II: The Global Carbon Cycle (feat: P) etc. Please don’t forget to do your evaluations! Ecology in the News Warming is melting permafrost CO2 Methane Ecology in the News Phosphorus: key element in constructing lipid membranes and (mineral dust) fueling cells Decomposition Precipitation Phosphorus: key element in constructing lipid membranes and (mineral dust) fueling cells Decomposition Precipitation Phosphorus: key element in constructing lipid membranes and (mineral dust) fueling cells Decomposition Precipitation Phosphorus: key element in constructing lipid membranes and (mineral dust) fueling cells Decomposition Precipitation Carbon: the cool kid of the elements Carbon: the cool kid of the elements 4 outer valence electrons Carbon: the cool kid of the elements Carbon: it’s what’s for dinner You’re about 18-19% carbon!  Global Carbon Cycle All macromolecules in living things contain CARBON Carbon is fixed from the atmosphere by primary producers through photosynthesis Inorganic à organic Much of the energy organisms use to fuel metabolic activities comes from OXIDATION OF ORGANIC CARBON COMPOUNDS (e.g. glucose)  Global Carbon Cycle All macromolecules in living things contain CARBON Carbon is fixed from the atmosphere by primary producers through photosynthesis Inorganic à organic Much of the energy organisms use to fuel metabolic activities comes from OXIDATION OF ORGANIC CARBON COMPOUNDS (e.g. glucose) Organic à inorganic Most carbon in atmosphere is CO2 and methane (CH4) these forms also found dissolved in oceans and fresh water aquatic systems also harbor carbonate (CO32−) Fluxes of carbon are driven by biological, chemical, and physical processes Biological … e.g. photosynthesis Chemical … e.g. formation of carbonate ions in ocean Physical… e.g. outgassing and dissolution in ocean Where is most of the carbon in the world? CARBON FLUX Atmosphere (CO 2, CH 4) HUMAN ACTIVITY 760 Fossil Photosynthesis Biomass 123 burning fuel burning, Altered Respiration 0.3 cement land use 1.7 120 manufacture 9.5 Dissolution Outgassing 92 91 Plant biomass 650 60 Soils 1,500 0.8 Runoff Marine biomass 3 59 Detritus 11 Ocean waters 39 38,920 Sand, detritus 1,200 Carbonate 0.2 precipitation Carbonate compounds Fossil in rocks fuels Sediments 150 18 x 106 3,700 The industrial revolution 1760 – 1820 Huge increase in coal consumption What period in history did humans 1.6 dramatically trillion tons accelerate of carbon released since then! their burning of fossil fuels?  NB: Some important points! CARBON emissions from fossil fuels have increased since the pre-industrial period. Prior to the industrial revolution, carbon in the fossil fuel reservoir was not exchanging with the atmosphere. CARBON from fossil fuels comes from dead organisms that have been buried for millions of years Fossil fuels are a non-renewable resource. Learning Catalytics All that CO2 is just going to make plants grow more and absorb all the CO2! 6m 1m Learn that Cat alytics The flux rate from land to the atmosphere is greater than the flux rate from the ocean to the atmosphere. a. True b. False  Biodiversity and Ecosystem Function Ecosystem function: the ecological processes that control the fluxes of energy, nutrients and organic matter through an environment Ecosystem Functions provide Ecosystem Services Ecosystem Functions provide Ecosystem Services Ecosystem Functions provide Ecosystem Services Ecosystem Functions provide Ecosystem Services  So what happens to ecosystem functions when we lose biodiversity? The answer depends on relationship between biodiversity and ecosystem function Potential relationships between biodiversity and ecosystem function saturating linear accelerating Potential relationships between biodiversity and ecosystem function saturating linear accelerating  Experimental approaches Biodiversity experiments at Cedar Creek  saturation of ecosystem function strongest effects of biodiversity at low species number Tilman and Downing: Biodiversity and Stability in Grasslands. Nature 6461 (1994): 363-365. So what are the mechanisms?  colors = different species height = productivity Potential mechanisms sampling effect (or “species selection”) - diverse systems tend to include highly productive species  colors = different species height = productivity Potential mechanisms sampling effect (or “species selection”) - diverse systems tend to include highly productive species complementarity - niche partitioning (or positive interactions among species)  colors = different species height = productivity Potential mechanisms sampling effect (or “species selection”) - diverse systems tend to include highly productive species complementarity - niche partitioning (or positive interactions among species) insurance - some species maintain function when others fail for example, green and orange species are susceptible to drought, but red and purple species are not.  Overall conclusions biodiversity loss reduces the efficiency of resource use, biomass production, decomposition, etc. biodiversity increases stability of ecosystem function impact of biodiversity on single ecosystem functions are typically linear or saturating diverse communities more productive b/c they contain highly productive species (sampling effect) AND differences in functional traits (complementarity) Cardinale et al. 2012; Nature 486:59-67 Have a great break!