12/6 quiz

Question 1

what are the different ways nitrogen can move through a system?

Answer 1

nitrification or denitrification

assimilation

fixation

decomposition

Question 2

what part of the nitrogen cycle is done by anaerobic bacteria?

Answer 2

denitrification

Question 3

what part of the nitrogen cycle is done by aerobic bacteria?

Answer 3

decomposition and nitrification

Question 4

what organism does nitrogen fixation?

Answer 4

bacteria

Question 5

how can nutrients be regenerated in an ecosystem?

Answer 5

decomposition

weathering

biological accumulation

Question 6

how can nutrients be lost from a system?

Answer 6

disturbance

Question 7

what is weathering?

Answer 7

the break down of inorganic matter

Question 8

what is decomposition?

Answer 8

the break down of organic matter

Question 9

what is biological accumulation?

Answer 9

the stuff we eat and store as biomass

Question 10

how can species affect nutrient cycling?

Answer 10

increase n-fixation and potentially facilitate colonization of invasive species

Question 11

what is decomposition essential for?

Answer 11

nutrient regeneration

Question 12

what are the four ways decomposition can take place?

Answer 12

leaching of soluble material into water

consumption by large detritivores

breakdown of wood and leaves by fungi

bacterial consumption of practically anything

Question 13

why does costa rica have poorer soils than north carolina?

Answer 13

decomposition occurs faster in CR so soil is more exposed to rain and therefore run off

Question 14

what influences the rate of decomposition?

Answer 14

temperature (biological processes happen faster at higher temps)

nutrient content

tissue quality

Question 15

how does regeneration differ between land and water?

Answer 15

land: takes place close to roots, decomposition is mostly aerobic

water: photic zone is far removed from sediments, decomposition is mostly anaerobic

Question 16

what is the photic zone?

Answer 16

where light is present in an aquatic system

Question 17

what results from anaerobic decomposition in aquatic systems?

Answer 17

lots of nutrients are stuck in sediments at the bottom of the system and can’t be recycled

Question 18

what are ways scientists have collected data about nutrients?

Answer 18

collecting tree litter and matter in streams

Question 19

what is the Hubbard Brook experiment?

Answer 19

experimental set up of one deforested and one forested basin controlled by Harvard

Question 20

what are the main findings of the Hubbard Brook experiment?

Answer 20

greater nutrient output is run off from the deforested basin

forest slows and moderates stream flow

Question 21

what is an example of a disturbance that caused a lot of soil nutrient loss?

Answer 21

the dust bowl

Question 22

what factors contributed to the dust bowl?

Answer 22

plowing, wind, and drought

a lot of nutrients lost to the ocean

Question 23

during the hubbard brook experimental forest case study, why didn’t the trees recover after emissions declined

Answer 23

it takes longer for acidity of soil to recover

particulate declined, which was a major source of calcium

Question 24

what are particulates?

Answer 24

tiny particles suspended in the air/water

Question 25

what does a decline in particulate matter mean?

Answer 25

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

Question 26

true or false: acid rain caused tree death

Answer 26

false, it did not directly cause tree deaths

Question 27

what does primary production control?

Answer 27

the flow of energy through an ecosystem

Question 28

what does decomposition control?

Answer 28

the regeneration of nutrients in an ecosystem