nutrient cycles Flashcards
(28 cards)
How is nitrogen fixed to be accessible by plants?
In using certain types of bacteria
What is nitrogen fixed into?
Ammonium ions
What can some nitrogen fixing bacteria form associations with?
Leguminous plants
What do the bacteria get from these plants in return?
Carbohydrates and vitamins produced by the plant during photosynthesis
What is nitrification?
Oxidation of ammonia and ammonium ions in the soil into nitrites and the nitrates
What does this?
Nitrifying bacteria
What type of microorganisms are they?
Aerobic microorganisms
What provides more oxygen and air for these microorganisms?
Ploughing
How many types are needed for nitrification?
2 types- one for nitrites then one to nitrates
How are nitrates absorbed into the plant?
Through active transport in the roots
How do consumers get nitrogen?
Through feeding off the plant or other animals which feed off plants
What is ammonification?
The production of ammonia from organic compounds e.g. protein, DNA/RNA
Which microorganisms do this?
Saprobiotic decomposers
What is denitrification?
The conversion of nitrates into gaseous nitrogen by denitrifying bacteria
What types of microorganisms are they?
Anaerobic
Where are they most commonly found?
Waterlogged soil
What reduced the amount of these bacteria?
Ploughing
How are phosphate ions released into the soil?
Weathering of rocks
How will this enter the food chains?
It will be passed through aquatic food chains
How are phosphate ions absorbed into the plant?
Through the roots
What do some fungi do?
Form mutualistic relationships with plant roots
What are these known as?
Mycorrhizae
What do the fungi consist of?
Hyphae
What are they?
Long thin strands which connect with the plant roots and extend into the soil maximising the surface area
