Biogeochemistry Flashcards
Biogeochemical cycles involve what?
Biotic and abiotic (geographical and chemical) components
General model of nutrient cycling:
- elements occur in 4 major reservoirs
- a variety of biotic and abiotic processes move elements between reservoirs
what is permineralization?
Hardening of minerals that enter the pores/cavities of dead organisms
What is fossil fuel burning?
releases organic and inorganic molecules (nitrogen oxides, sulphur dioxide, heavy metals)
How is sedimentary rock formed?
- deposition/sedimentation of particulate minerals and detritus
- much of material originates from weathering and erosion
What is weathering?
Caused by the atmosphere (wind and water) and wildlife
- May be physical or chemical
What is erosion?
Transportation and deposition of weathered material
What is the carbon cycle?
- major component of organic molecules
- Photosynthesis, respiration and decomposition
- Major reservoirs = fossil fuels, soils
What is the nitrogen cycle?
- Nitrogen = essential component of proteins and nucleic acids
- Key roles: microbes and plants
- major reservoirs = atmosphere, soils, sediments
What is the phosphorus cycle?
- Important component of nucleic acids, phospholipids, ATP
- major reservoirs = marine sedimentary rocks, soil, ocean
What is the water cycle?
Water is essential for life and can play important role in moving elements/nutrients
Most chemical cycles now disrupted by what?
Human activities
Excess nutrients can have toxic effects:
e.g Gulf of Mexico dead zone
nutrient enrichment stimulates phytoplankton blooms, decomposition leads to oxygen depletion
What does fossil fuel burning lead to?
rapid increase in atmospheric CO2 concentrations
How will global warming effect ecosystems?
- increased productivity and decomposition
- changes in water availability?
