Chapter 23: Biogeochemical Cycles Flashcards
Biogeochemical cycles?
this is how nutrients flow back and forth from living to nonliving components of the ecosystem
- bio = living
- geo= rocks and soil
- chemicals = reactions involved
What are important components of biogeochemical cycles?
- green plants, decomposers, air and water
What are the two source types of biogeochemical cycles?
- Gaseous - reservoir atmosphere and oceans
- Sedimentary cycles - reservoir soil, rocks and minerals
* *both are tied to the water cycle medium which moves elements and other materials
What are the nutrient inputs?
- from atmosphere for gaseous cycle or by weathering of rocks and minerals for sedimentary cycles
What are the atmospheric inputs?
- wetfall nutrients brought by precipitation (like rain, fog and precipitation etc)
- dryfall nutrients brought by airborne particles and aerosols
What are the gaseous outputs aka loss of nutrients?
- in gaseous form (CO2 from respiration)
- As organic matter e.g. carried by surface flow into streams, transferred by herbivores
- leaching of nutrients from soils
- harvesting and fire
What are the three components of biogeochemical cycles?
- inputs, internal cycling and outputs
Describe a generalized biogeochemical cycle of an ecosystem!
- NPP
- internal cycling:
- litter fall –> dead organic matter(output) –> decomposition/mineralization –> soil nutrients (output) -(input from the weathering of rocks and minerals) –> plant uptake —> incorporation into plan tissues —> atmospheric input —> NPP
- *loses: rain, run off, erosion
Carbon Cycle:
-is carbon and energy flow separable?
- nope they are inseparable
Carbon Cycle:
- source of all carbon is???
- CO2
Carbon Cycle:
- PS draws CO2 from???
- air and water and converts it into organic material
Carbon Cycle:
- where does carbon from PS pass on to from plants?
- passed to herbivores and carnivores and then is released as CO2 by respiration
Carbon Cycle:
- dead organic material?
- it is decomposed
- decomposers release CO2 to atmosphere through respiration
Carbon Cycle:
- carbon sinks?
- peat, coal, oil, gas
Carbon Cycle:
- carbon sources?
- respiration and photosynthesis
- diffusion from aquatic environments!
Variation in Carbon cycling:
- Net ecosystem productivity?
- difference between carbon uptake in PS and carbon loss due to autotrophic and heterotrophic respiration
Variation in Carbon cycling:
- rate of carbon cycling depends on?
- rates of primary productivity and decomposition. These are dependent on temperature and precipitation
Variation in Carbon cycling:
- Daily cycles?
- no PS at night, therefore higher CO2
Variation in Carbon cycling:
- Seasonal fluctuation?
- more PS and lower CO2 during growing season
Variations in atmospheric CO2 during a typical year in Barrow, Alaska?
- lower in the summer time, higher in winter bc PS
- it builds up in the atmosphere bc there is no PS to bring it down cause it is too dark (winter)
- seasonally Co2 builds up
Global Carbon Cycle:
- most carbon on earth is where?
- buried in sedimentary rocks and not involved in cycle (sink)
Global Carbon Cycle:
- global carbon cycle involves?
- atmosphere, ocean and land
Global Carbon Cycle:
- ocean?
- contains a majority of active carbon pool (bicarbonate and carbonate ions )
Global Carbon Cycle:
- how is carbon cycled around the globe?
- atmosphere and in ocean currents
Global Carbon Cycle:
- sources and sinks of carbon?
- sources: CO2
- sinks: sediments, rocks, fossil fuels, coral reefs
Order in order of greatest sink of carbon to least:
Atmosphere, vegetation, recoverable fossil fuels, ocean, soils and dead organic matter
- Ocean > Recoverable fossil fuels > Soils and dead organic matter > Atmosphere > vegetation
Carbon cycling exchanges:
- main site in ocean?
- surface water is the main site of exchange of CO2 via diffusion between the atmosphere and the water …undersaturated it will absorb it..saturated it will release it. The ocean regulates our climate
Carbon cycling exchanges:
- Ability of surface waters to take up CO2 is determined by?
- action with hydrogen ions to form carbonic acid, bicarbonate and carbonate ions