exam 3 pt 12 (biogeochemical cycles -> ozone)

biogeochemical cycle

nutrient circuits in ecosystem involve biotic and abiotic components

water cycle

moves by process of evaporation, transpiration, condensation, precipitation + movement through surface and groundwater

carbon cycle

CO₂ taken up + released through photosynthesis/respiration

→ reserves of CO2 include fossil fuels, soils, sediments, solutes in oceans, plant + animal biomass, and the atmosphere

how to get CO₂ into the atmosphere?

cellular respiration

how to get CO₂ out of the atmosphere?

photosynthesis

nitrogen cycle

must be converted to nitrate or ammonium for uptake b plants via N fixation bacteria

→ the main reservoir of N is the atmosphere

phosphorous cycle

largest reservoirs are in sedimentary rocks, oceans, and organisms

when plants die, they decompose and run off into sediment. the sediment will turn into rock. what cycles that sediment upward?

geologic uplift

how does sediment get out of rocks when it comes to geological uplift?

erosion

_______ removes from ecosystem nutrients that would usually be cycle back into the soil in nature

agriculture

main nutrient lost through agriculture

nitrogen

industrially produced fertilizer is typically used to what?

replace lost nitrogen

→ but it effects the ecosystem poorly because it runs off into a body of water which causes eutrophication

critical load

a nutrient is the amount that plants can absorb without damaging the ecosystem

→ any extra of something will cause that nutrient to run off and let eutrophication grow out of control

why is there dead zones in the summer off the coast of mexico?

nutrient run off from the US midwest causes eutrophication which makes parts of the water anoxic

why are toxins harmful?

become concentrated in successive trophic levels

→ i.e. little fish are eaten by big fish. as you get to fish we eat, those fish have a LOT of mercury in them because it builds up with each little fish they eat

biological magnifiation

concentrates toxins at higher trophic levels where biomass is lower

temperatures and carbon emissions fluctuate all the time. what is the issue with them being released so frequently though?

they cycle, but in an UPWARD trend

trees grow more with the addition of more carbon dioxide, yes. but is it enough to offset climate change?

no

→ we are pumping CO₂ much faster than what tress can clean up

the ozone layer cycles, yes. but what is alarming about its cycle?

its cycle is in a downward trend

how did the ozone stabilize?

international agreement signed in 1987 that resulted in decrease of ozone depletion