Nutrient Cycles and Global Warming Flashcards
What is ammonification
The nitrogen gas is in pairs, they do not want to separated easily. Nitrogen combines with oxygen due to lightning to form nitrogen oxide. Saprobiotic microorganisms feed on dead material and waste to release ammonia which forms ammonium ions
What are saprobiotic microorganisms and what do they do
Decomposers, they feed on dead material and waste, releasing ammonia which forms ammonium ions
Ammonium ions are oxidised to….
Nitrite ions
Nitrite ions are oxidised to….
Nitrate ions
Nitrate ions are….
Reactive
What is nitrification
This is carried out by free-living soil microorganisms called nitrifying bacteria. Ammonium ions oxidised to nitrite ions by nitrosomonas bacteria,these oxidised to nitrate ions (which are reactive) by nitrobacter bacteria.
What is nitrogen fixation
Nitrogen gas converted into nitrogen containing compounds by….
free living nitrogen fixing bacteria, which reduce gaseous nitrogen to ammonia and amino acids
Mutualistic nitrogen-fixing bacteria, called Rhizobium, live in nodules on roots of plants, obtain carbohydrates from plant, turn into amino acids
If there is plenty of oxygen in the soil then these products enter the plants by active transport
What is denitrification
Soils are waterlogged and lack oxygen. Fewer nitrifying and nitrogen fixing bacteria= increase in anaerobic denitrifying soil nitrates. Gaseous nitrogen produced. Decrease in availability of nitrogen containing compounds. Soils need to be aerated through ploughing
What else can cause the nitrogen cycle to occur
Industry
Lightning
What are the 4 major processes involved in the carbon cycle
Photosynthesis
Respiration
Decomposition
Combustion
Why do respiration and photosynthesis cause fluctuations in CO2 conc
Respiration adds CO2 atmosphere, photosynthesis removes CO2. Both of these vary on a daily and yearly basis causing fluctuations
What is the greenhouse effect
Effect of greenhouse gases absorbing outgoing energy so that less is lost to space
3 main greenhouse gases
CO2
Water vapour
Methane
Human activities like ……………… have increased atmospheric concs of CO2 and methane
Burning fossil fuels
Farming
Deforestation
How could global warming affect crop yield
Increasing CO2 conc= increase in crop yield. CO2 is a limiting factor of photosynthesis so increasing concs means crops grow faster, increasing yields
How could global warming affect insect pests
Can affect life cycle of some insect pests. Eg global warming means some insect pests go through their larval stage quicker and emerge a adults earlier. Global warming can also affect numbers of insect species…. Some becoming more abundant (warmer wetter summers have led to increase in Mosquitos), others less abundant (some tropical insect species can only thrive in specific temp ranges so if it gets too hot fewer insects can reproduce successfully)
How could global warming affect wild animals and plants
Can affect distribution, some become more widely distributed (species need warmer temps may spread further as conditions they thrive in exist over bigger area), others less distributed
Can also affect numbers, some become more abundant, others less
The nitrogen cycle shows…
How nitrogen is converted into a useable form and then passed on between different living organisms and the non-living environment
What is leaching
When water soluble compounds in soil are washed away, often into nearby ponds and rivers. If nitrogen fertiliser is leached into waterways can cause eutrophication
