ECOSYSTEMS AND MATERIAL CYCLES Flashcards
(15 cards)
what do organisms compete for?
food, water, space, light, carbon dioxide/oxygen, mate
what is interdependence?
organisms depending on eachother for survival. When this happens a community is formed
what are abiotic factors in an ecosystem?
non-living factors, e.g light, temperature, moisture, soil pH, carbon dioxide and oxygen concentration
what are biotic fathers in an ecosystem?
the impact of other organisms on an ecosystem e.g. food, predators/prey and pathogens
how do you do sampling with a quadrat?
place quadrat in random positions in area (ideally 10% of area), count number of chosen organism in each. Calculate mean then multiply by total area to get estimate for population. Moving it along a transect allows you to observe changes in population density over a distance
what are biotic fathers in an ecosystem?
the impact of other organisms on an ecosystem e.g. food, predators/prey and pathogens
what organisms are involved in food chains?
producer- produces biomass (algae, plants), primary consumer (herbivore, omnivore), secondary consumer (carnivore, omnivore), tertiary consumer (carnivore/ omnivore)
what is an apex predator?
those always at the top of the food chain, and have no natural predator
All life is carbon-based. What does carbon-based mean?
carbon is recycled when an organism dies and decomposes, and they excrete carbon dioxide while alive which can help plants to grow (bacteria also do this)
what is potable water?
water that has low enough levels of dissolved salts and minerals that it is safe to drink
what is the nitrogen cycle?
nitrogen converted into nitrates by nitrogen fixing bacteria (FIXATION), other bacteria and fungi convert protein into ammonia during decomposition (AMMONIFICATION), ammonia converted into nitrates by nitrifying bacteria (NITRIFICATION)- these are used by plants (ASSIMILATION), denitrifying bacteria convert nitrates back into nitrogen (DENITRIFICATION)
what is eutrophication?
nitrate filled fertilisers run off into standing water (ponds, lakes), causes algae on the surface to bloom causing a barrier that stops light from reaching underwater plants which then die, respiring bacteria feeds on the dead plant material uses up more oxygen in the water starving fish and other creatures and they then die
what is biodiversity?
the variety of species of organisms that exist in an ecosystem
what contributes to global warming?
carbon dioxide and methane
what can impact biodiversity?
HUMAN DEVELOPMENT- destruction of habitats due to waste causing pollution, LAND- needed by us for building, farming and disposing of waste, PEAT BOGS- affects the habitats of many organisms, reducing biodiversity, burning peat releases carbon dioxide contributing to global warming, DEFORESTATION- flattening forests reduces biodiversity, usually done to create farmland
