Energy and ecosystems Flashcards
What are producers?
photosynthetic organisms that manufacture organic substances using light energy, water, CO2 and mineral ions
what are consumers?
organisms that obtain their energy by feeding on other organisms rather than using the energy of sunlight directly.
what are saprobionts?
a group of organisms that break down the complex materials in dead organisms into simple ones
what is a food chain?
a feeding relationship in which the producers are eaten by primary consumers. each stage in the chain is referred to as a trophic level
what is a food web?
many food chains linked together within a single habitat.
what is biomass?
the total mass of living material in a specific area at a given time
What is the equation for net primary production?
gross primary production
–
respiratory losses
What are the four main stages of the nitrogen cycle
– ammonification
– nitrification
– nitrogen fixation
– denitrification
what is ammonification?
the production of ammonia from organic nitrogen-containing compounds.
what is nitrification?
plants using light energy to produce organic compounds or bacteria using chemical reactions from organic ions to create energy
what is nitrogen fixation
nitrogen gas is converted into nitrogen-containing compounds. The two main types are free-living nitrogen-fixing bacteria or mutualistic nitrogen-fixing bacteria
what is denitrification?
a process where nitrate is reduced and ultimately produces molecular nitrogen or other nitrogenous gases.
what is organic fertiliser?
consists if dead and decaying remains of plants and animals as well as animal waste
what is artificial fertiliser?
mined from rocks and deposits and then converted into different forms and blended together to give the appropriate balance of minerals for a particular crop
what are the effects of nitrogen-containing fertilisers?
– reduced species diversity
– leaching
– eutrophication
what is leaching?
leaching is the process by which nutrients are removed from the soil
what is eutrophication?
eutrophication is the process by which nutrient concentrations increase in bodies of water?
