Ecology final week 15

Nitrogen cycle
Click the card to flip 👆
1 / 29
Terms in this set (29)
Carbon cyclePrimary building block of organisms; large atmosphere sink; fluxes driven by fundamental energy pathways in ecosystems: photosynthesis and respirationShort term CO2Increase in atmospheric CO2; atmospheric CO2 ~400ppm and rapidly risingFossil fuelsBurnt at high rate; carbon stored over millions of years released in a few decades; increasing atmospheric CO2 (importance of perspective)Greenhouse effectHeats atmosphere; visible light hits earth, reradiated as infrared; CO2 absorbs infrared radiation, heats atmosphere; expectation - with addition of more CO2 climate of earth changesCO2 natural sourceRespirationN2O natural sourceSoil microorganismsCH4 natural sourcesWetlands; termites; oceans and freshwaterCO2 human sourcesFossil fuel combustion; land clearing; biomass burningN2O human sourcesLand clearing; biomass burning; fossil fuel combustion; nitrogenous fertilizerCH4 human sourcesFossil fuel mining and processing; rice paddies; enteric fermentation; animal waste; sewage; landfills; biomass burningTemperature anomaliesDifference between observed temperature and long-term average temperature at a location; how much each location has warmed or cooled relative to the long-term meanGeneral circulation modelsLast century - average temperature up by ~.3 to .6 degrees C; last 40 years - average temperature up by ~.2 to .3 degrees C; climate models based only on greenhouse gases predict 1 degree C increaseOcean acidificationSince the beginning of Industrial Revolution, pH of surface ocean waters have fallen by .1 pH units; approximately 30% increase in acidity; CO2 + H2O --> H+ HCO3-Consequences of climate changeTemperatures will not rise uniformly; different regions will change in uniqe ways; depends on prevailing winds, ocean currents, mountain ranges, etc.; increase global precipitation; some areas increased drought, more severe storms, higher snowfallConsequences of climate change to natural ecosystemChange in species ranges to poles or higher elevations; shifts in life-cycles; extinctions; many species near tolerance limit; tropics warmer and drier; changes in productivity, energy flow, ecosystem services, etc.Consequences of climate change to northern agricultureAgricultural production increases; longer growing season; more CO2Consequences of climate change to agriculture in other areasDecline in agriculture; reduced precipitation; summer droughtConsequences of climate change to sea levelRising; thermal expansion and ice meltingConsequences of climate change to humansHealth effects (direct and indirect); heat; tropical diseases - dengue, yellow fever, malaria