Global Nitrogen cycle Flashcards
What are the major pools and fluxes in the global nitrogen cycle?
The major pools are mostly in soils, terrestrial vegetation, sediment, biota, surface water and deep water. The major Fluxes are land and Aquatic Denitrification, biological and industrial nitrogen fixation, deposition, ocean emissions, land emission and fossil fuels.
What is nitrogen fixation and denitrification?
Nitrogen fixation is when Dinitrogen Gas is converted into Ammonium, it’s essential to plants and animals that cannot readily use the atmospheric nitrogen. It is frequently found in habitats with abundant light and low nitrogen availability.
Where and under what circumstances are nitrogen fixation and denitrogenfixation most likely to occur on land and in the ocean?
On land, Nitrogen fixation occurs when plants form a symbiotic relationship with nitrogen fixing bacteria trading carbohydrates for nitrogen. Similarly nitrogen fixation in the ocean is crucial for primary production and ecosystems, it occurs with the assistance of marine microorganisms such as diazotrophic and cyanobacteria.
What are the major sources of anthropogenic nitrogen?
The major sources of anthropogenic nitrogen are fossil fuel combustion and synthetic nitrogen fertilizer.
What impacts do anthropogenic nitrogen inputs have?
Nitrogen fertilizers are used on agricultural fields to increase growth however, excessive use/application can lead to water pollution. This is because runoff from fields contaminate the surface and ground water which can cause harmful algal blooms/poor water quality.
How do oceanographic controls over stratification and mixing influence nutrient absorption and use in marine phytoplankton?
Oceanographic control over stratification and mixing are very important when it comes to regulating nutrient absorption/use by marine phytoplankton. It is essential to determine growth and productivity of phytoplankton.
What are the major pools and fluxes in the global phosphorus cycles?
The major pools in the phosphorus cycle are rocks/sediments, land/oceanic biota, and deep ocean.
The major fluxes are weathering, recycling, river flux, biological pump, upwelling, fertilizer, burial and remineralization.
What are the major pools and fluxes in the global sulfur cycles?
The major pools in the global sulfur cycle are soils, vegetation, sedimentary/rocks, biota, surface water, deep water and lakes. The major Fluxes, Volcanos, Biological gasses, disposition, seaspray, emissions and biogenic.
How have human activities changed the global phosphorus and sulfur cycles?
Human activities have made it so that there is an increase of CO2 emissions, nitric oxides and multiple sulfur gasses due to burning fossil fuels.
What is Liebig’s Law of the Minimum?
This law states that growth is limited by the most limiting resource. It does not matter whether you have an abundance of all other resources needed to grow, if one resource is limited it affects the intake of the rest.
What controls the distribution of nitrogen fixers in the ocean?
Nutrient, light, iron and phosphorus availability, temperature, light availability and oxygen levels control the distribution of nitrogen fixers in the ocean.
Why are nitrogen fixers found in post-disturbance (e.g., after a glacier recedes) plant communities on land?
Nitrogen fixers are found in post-disturbance plant communities on land Because Nitrogen fixers (in this case nitrogen fixing plants) thrive in nutrient poor soils, they are able to create symbiotic relationships with nitrogen fixing bacteria on their roots and contribute to soil fertility.
