All Flashcards
What are the steps of nitrogen fixation?
Atmospheric N2 converted to ammonia (NH3) or nitrate (NO3) by biotic (bacteria) or abiotic (lightning) processes.
What are the steps of nitrification?
Ammonia (NH3) converted to nitrite (NO2-) and then to nitrate (NO3-) by bacteria.
What are the steps of mineralization?
Decomposers break down dead organisms, converting organic nitrogen to ammonium (NH4+).
What are the steps of denitrification?
Nitrate (NO3-) converted back into nitrogen gas (N2) and nitrous oxide (N2O) by specialized bacteria.
What is the effect of fertilizer overuse on water bodies?
Eutrophication: excess nitrogen runoff leads to algal blooms, oxygen depletion, and harm to aquatic life.
What is the effect of excess nitrogen on species richness?
Reduced species richness: plants that need more nitrogen outcompete others, decreasing the variety of species.
How does fossil fuel combustion affect the nitrogen cycle?
It can convert N2 directly into NO3, contributing to atmospheric deposition and acid rain.
What are the consequences of increased nitrogen deposition from the atmosphere?
Acidification of soils and water bodies, altered plant communities, and potential harm to sensitive ecosystems.
What is the effect of nitrogen runoff on coastal ecosystems?
Harmful algal blooms, dead zones due to oxygen depletion, and disruptions to marine food webs.
How does deforestation impact the nitrogen cycle?
Reduces nitrogen uptake by plants, leading to increased nitrogen runoff and potential water pollution.
What is the impact of nitrogen fertilizer production on the environment?
Energy-intensive process that contributes to greenhouse gas emissions and air pollution.
How does livestock farming affect the nitrogen cycle?
Concentrated animal waste can lead to high levels of ammonia emissions and nitrogen runoff, causing water and air pollution.
What are the effects of nitrogen saturation in terrestrial ecosystems?
Increased leaching of nitrate, acidification of soils, and altered plant community composition.
How does climate change influence the nitrogen cycle?
Altered temperature and precipitation patterns can affect nitrogen fixation, denitrification, and decomposition rates.
What are the steps of nitrogen fixation?
Atmospheric N2 is converted into ammonia (NH3) or nitrate (NO3) by biotic (bacteria) or abiotic (lightning, combustion) processes.
What are the steps of nitrification?
Ammonia (NH3) is converted into nitrite (NO2-), then nitrite is converted into nitrate (NO3-) by bacteria.
What are the steps of mineralization?
Decomposers break down dead organisms and waste, converting organic nitrogen back into inorganic ammonium (NH4+).
What are the steps of denitrification?
Nitrate (NO3-) is converted back into nitrogen gas (N2) and nitrous oxide (N2O) by specialized bacteria.
What is the assimilation process?
Plants absorb nitrate (NO3-) through their roots and incorporate it into their tissues to synthesize proteins and DNA.
Describe the overall flow of nitrogen in the nitrogen cycle.
Nitrogen moves from the atmosphere to the soil (fixation), then to plants and animals (assimilation), back to the soil (mineralization), and finally back to the atmosphere (denitrification).
How does nitrogen cycle through an ecosystem?
Nitrogen cycles through fixation, nitrification, assimilation, ammonification, and denitrification, with bacteria playing key roles in several steps.
Describe the role of bacteria in nitrification.
Bacteria convert ammonia (NH3) to nitrite (NO2-) and then to nitrate (NO3-), making nitrogen available to plants.
What happens to nitrogen after assimilation by plants?
Nitrogen becomes part of the plant's tissues, and consumers obtain nitrogen by eating the plants.
How does denitrification complete the nitrogen cycle?
Denitrification converts nitrate back into nitrogen gas, returning it to the atmosphere and balancing the cycle.