Ecosystems Flashcards
(16 cards)
What is the definition for ecosystem?
All the interacting living and non living conditions in an area
-They vary in size and are dynamic
What are the 3 biotic factors that affect ecosystems
biotic=living
-Predation
-Competition
-Hunting/poaching
What are the 3 Abiotic factors that affect ecosystems
Abitoitc= non-living
Light
Temp
PH
What does Biomass mean?
The mass of all living mats present in an ecosystem
Why is there less and less biomass transfer down the ecosystem chain?
Biomass/net production is lost due to respiratory losses deceases and the fact that some parts of organisms are consumed (bones)
What is the formula to calculate ecosystem efficiency?
[Biomass transferred]
[—————————- ]X 1000
[Biomass intake ]
How can farmers optimise ecosystem efficiency? (2)
Simplify food webs
Reduce respiratory losses
What does in this context succession mean?
When an ecosystem changes from simple to complex overtime
What are the 3 serial stages of succession?
1)Barren and uninhabited land is colonised by pioneer species which change the environment and make it less hostile so other species can live there
2)Herbs and brush begin to grow (INTERMEDIETE COMMUNITY) they eventually decompose and give nutrients to the ground making the environment less hostile
3)Over time a stable community is established known as the CLIMAX community
What is deflected succession?
This is when humans intervene usually through agriculture and halt succession to climax community
Please explain the carbon cycle
CO2 in the atmosphere is used by producers on photosynthesis and converts it to a Carbon compound - This is called carbon fixation
Consumers eat the producers thus gaining the carbon compound
both producers and consumers release CO2 back into the atmosphere via respiriation
Dead producers and consumers are either broken down by decomposers or turned into fossil fuels to be combusted
What are the 4 key parts of the nitrogen cycle?
Nitrogen fixation
Nitrification
Ammonification
Denitrification
What happens during nitrogen fixation?
Atmospheric nitrogen is converted into ammonia by the bacteria Rhizobium and Azobacter.
Rhizobium lives in root nodules of legumes plants and give the ammonia straight to the plant
Azobacter converts ammonia to ammonium
What happens during nitrification? samosa nitro boost
Nitrosomonas convert ammonium to nitrites and nitrobacter converts the nitrites to nitrate. (this process is aerobic so needs O2)
What happens in ammonification?
Dead producers and consumers containing nitrogen compounds are broken down via decomposers which from NH3 which then in soil goes NH4+ (ammonia)
What happens in denitrification?
Denitrifying bacteria convert Nitrate into atmospheric nitrogen under anaerobic conditions
