Ecosystems Flashcards
(27 cards)
ecosystem
A relatively self-contained unit consisting of a community of species interacting with each other and with the non-living components of their environment
biotic components
animals,plants
abiotic components
non living (water, weather, temperature)
community
multiple populations interacting in the same area
populations
individuals from same species living in the same area
habitat
where plants or animals live
niche
the role of an organism plays in its ecosystem
-what it feeds on / excretes
consumers
feed on producers to use chemical energy for respiration
omnivore
eat both plants and meat
carnivore
eat meat ONLY
herbivore
eat plants ONLY
decomposers
-bacteria,fungi - feed on waste material or dead organisms
7 uses of energy
Movement
Reproduction
Sensitivity
Nutrition
Excretion
Respiration
Growth
Ecological efficiency
biomass at higher trophic level / biomass at lower trophic level
eg biomass of primary consumer / producer biomass
productivity
the rate at which energy passes through each trophic level
why is energy lost in plants
-some light misses
-some light reflects
-not the right wavelength for photosynthesis
-energy used in mrs nerg
improve primary productivity
-light
-more efficient wavelengths of light
-irrigate crops
-keep temperature optimum
-crop rotation (swaps where planted to regain nutrients)
-reduce competition ( from weeds etc)
improve secondary productivity
-use steroids on young to increase growth rate
-selective breed for larger, quicker growing
-use antibiotics so energy is not lost fighting pathogens
biomass
total weight of living organisms in an area
transferred through trophic levels by consumption
mass of carbon or dry mass tissue
efficiency
biomass transferred / biomass uptake x100
roles of microorganisms in the nitrogen cycle
nitrogen fixing bacteria -rhizobium in roots convert gaseous nitrogen into ammonia
nitrifying bacteria- nitrosomonas convert ammonium compounds into nitrites
nitrobacter then converts nitrites to nitrates
role of organisms in the carbon cycle
respiration of animals releases carbon dioxide into atmosphere
photosynthesis of plants removes carbon dioxide from atmosphere
decomposers - decay plant and animal material into carbon dioxide
primary succession
when an area previously devoid of life is colonised by a community or organisms
pioneer species colonise the area
the die and compose leaving nutrients in ground
overtime this allows more complex organisms to live
climax community
final stage of succession where ecosystem is balanced and stable
environment no longer changing
