12/6 quiz Flashcards
what are the different ways nitrogen can move through a system?
nitrification or denitrification
assimilation
fixation
decomposition
what part of the nitrogen cycle is done by anaerobic bacteria?
denitrification
what part of the nitrogen cycle is done by aerobic bacteria?
decomposition and nitrification
what organism does nitrogen fixation?
bacteria
how can nutrients be regenerated in an ecosystem?
decomposition
weathering
biological accumulation
how can nutrients be lost from a system?
disturbance
what is weathering?
the break down of inorganic matter
what is decomposition?
the break down of organic matter
what is biological accumulation?
the stuff we eat and store as biomass
how can species affect nutrient cycling?
increase n-fixation and potentially facilitate colonization of invasive species
what is decomposition essential for?
nutrient regeneration
what are the four ways decomposition can take place?
leaching of soluble material into water
consumption by large detritivores
breakdown of wood and leaves by fungi
bacterial consumption of practically anything
why does costa rica have poorer soils than north carolina?
decomposition occurs faster in CR so soil is more exposed to rain and therefore run off
what influences the rate of decomposition?
temperature (biological processes happen faster at higher temps)
nutrient content
tissue quality
how does regeneration differ between land and water?
land: takes place close to roots, decomposition is mostly aerobic
water: photic zone is far removed from sediments, decomposition is mostly anaerobic
what is the photic zone?
where light is present in an aquatic system
what results from anaerobic decomposition in aquatic systems?
lots of nutrients are stuck in sediments at the bottom of the system and can’t be recycled
what are ways scientists have collected data about nutrients?
collecting tree litter and matter in streams
what is the Hubbard Brook experiment?
experimental set up of one deforested and one forested basin controlled by Harvard
what are the main findings of the Hubbard Brook experiment?
greater nutrient output is run off from the deforested basin
forest slows and moderates stream flow
what is an example of a disturbance that caused a lot of soil nutrient loss?
the dust bowl
what factors contributed to the dust bowl?
plowing, wind, and drought
a lot of nutrients lost to the ocean
during the hubbard brook experimental forest case study, why didn’t the trees recover after emissions declined
it takes longer for acidity of soil to recover
particulate declined, which was a major source of calcium
what are particulates?
tiny particles suspended in the air/water
what does a decline in particulate matter mean?
calcium ions reduced acidity in soil and water, but is a nutrient for trees
calcium was leached away due to tree deaths, so acid rain was stealing nutrients from soil
true or false: acid rain caused tree death
false, it did not directly cause tree deaths
what does primary production control?
the flow of energy through an ecosystem
what does decomposition control?
the regeneration of nutrients in an ecosystem
