10.2- efficiency of ecosystems Flashcards
energy loss in trophic levels
-energy is lost as each trophic loevel
-mot all is transerred to enct level
what is a producer
-make food
-plants and algae trap light from sun and use it in photosynthsis to make ATP
what is a primary consumer
-organisms that eat producers, herbivores
secondary consumers
-animals that feed on herbivores, carnivores
tertiary consumers
-animals that feed on carnivores, usually top predators unless quaternary
what is an ecosystem?
-An ecosystem is a life-supporting environment. It includes all of the organisms living in a particular area known as a community, as well as all of the non-living elements of that particular environment.
-All organisms in an ecosystem interact with one another in complex ways. These are sometimes represented in food webs.
how is energy lost between trophic levels?
-some parts are the food are not or cannot be eaten e.g. bones
-some foods cannot be digested e.g. certain plant fibres
-energy lost to environment as heat or waste
3 types of ecological pyramids
-pyramid of number
-pyramid of biomass
-pyramid of energy
pyramid of number
-compare number of organisms at each trophic level
-producers at bottom to tertiary at top
-not great as e.g. small population of ladybirds eat a larger population of aphids
pyramid of biomass
-compare mass of biological material at each tropic level
-wet biomass very inaccurate as it is affected by water uptake in the soil
-dry involves destroying material, so a small sample is used and total biomass is calculated from it
-much more time consuming but more accurate
pyramid of energy
-amount of energy passing through each trophic level over a period of time -most accurate model of what is happening in an ecosystem
-energy remains same at every level but the size of different types of energy stores changes
-as you move along food chain, less energy in organisms and more in surrounding environment
how to calculate energy efficiency
energy transferred to biomass/ total energy supplied to organism
what is gross primary productivity
-rate at which plants capture sunlight to produce new plant material
net primary productivity
-energy transferred into biomass, available to next trophic level
net primary productivity calculation
NPP= GPP-respiration
energy transfer calculation
NPP/GPP multiplied by 100
what impacts NPP
-water within an ecosystem
-latitude (light available)
-plant density
nutrient cycling
-Energy flow through living organisms is unidirectional and is eventually lost to the environment as wasted heat.
-Matter, however, is continually recycled between living and non-living things.
what does the carbon cycle consist of?
-released during respiration of plants, animals and decomposers
-in decaying matter and waste
-stored in fossil fuels such as coal and oil
-released into atmosphere when fossil fuels are burned (combustion)
-used in photosynthesis to produce carbs
what is the nitrogen cycle
-recycling of nitrogen between biotic and abiotic phases of an ecosystem
parts of the nitrogen cycle
-decomposers act specifically on proteins, breaking them down to form ammonium compounds
-these ammonium compounds are then oxidised by nitrifying bacteria that convert them to nitrates
-these are returned back to soil and absorbed by plants
-nitrogen fixing bacteria in soil can convert nitrogen from soil into ammonia, which is then converted to nitrates by nitrifying bacteria
-legumes are particularly important (beans and peas) have nodules on their roots that are full of nitrogen fixing bacteria, an example of mutualism
-denitrifying are not helpful as they use nitrates as energy source and break them down again into nitrogen gas, reducing nitrates in soil
what is a carbon sink
-resivoir where carbon is removed from the atmosphere and ‘locked up’ in organic or inorganic compounds
