ecology 3 (ecosystems ecology)

Question 1

ecosystem

Answer 1

biotic community of organisms in an area plus the abiotic environment affecting that community

Question 2

trophic structure

Answer 2

the organization of organisms within an ecosystem based on their feeding relationships; how energy flows through a food chain by dividing organisms into different trophic levels

Question 3

primary producer

Answer 3

organisms that acquire their energy from sunlight and materials from nonliving sources

Question 4

primary consumer

Answer 4

organism that eats primary producers

Question 5

secondary consumer

Answer 5

organism that eats primary consumers

Question 6

tertiary consumer

Answer 6

organisms that eat secondary consumers

Question 7

detritivore

Answer 7

an animal which feeds on dead organic material

Question 8

decomposer

Answer 8

an organism that breaks down dead organic material;

Question 9

detritus

Answer 9

debris; accumulation of non man made/ natural material

Question 10

trophic level

Answer 10

each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy

Question 11

primary production

Answer 11

the amount of light energy converted to chemical energy by autotrophs (primary producers) during a given span of time

Question 12

gross primary production

Answer 12

total amount of production of biomass from solar energy

Question 13

net primary production

Answer 13

amount of production of biomass from solar energy minus the energy the plant uses for respiration

Question 14

what energy is available to consumers for energy

Answer 14

NPP

Question 15

biomass

Answer 15

the total mass of living organisms in an ecosystem at a given time

Question 16

limiting nutrient

Answer 16

limits the rate of production of biomass
ex. nitrogen

Question 17

production efficiency

Answer 17

a measure of how well a company uses its resources to produce goods or services

Question 18

trophic efficiency

Answer 18

the percentage of energy that is passed from one trophic level to the next in a food chain or food web; energy loss up tropic levels

Question 19

top down control

Answer 19

organisms at higher trophic levels in a food web regulate the populations of organisms at lower trophic levels

Question 20

bottom up control

Answer 20

availability of resources at the base of a food chain, like nutrients, water, or light, regulates an ecosystem

Question 21

how to calculate net primary production?

Answer 21

NPP = GPP – R(respiration)

Question 22

tropic cascade

Answer 22

a series of tropic interactions that result in changes in biomass and species composition; indirect effects

Question 23

secondary produtivity

Answer 23

amount of chemical energy in food converted to new biomass in a particular amount of space during a given period of time

Question 24

bioaccumulation

Answer 24

chemicals build up in an organism over time, becoming more concentrated than the chemical in the environment

Question 25

assimilated energy uses

Answer 25

energy used for growth (new biomass) and respiration

Question 26

not assimilated energy uses

Answer 26

feces/ waste

Question 27

pool

Answer 27

main reservoirs of elements/nutrients
*organic/inorganic
*avaibale/unavailable

Question 28

pool size

Answer 28

total amount of nutrient in a component of the ecosystem

Question 29

mean residence time

Answer 29

amount of time on average that a molecule spends in a pool

Question 30

turnover

Answer 30

rates of nutrients cycling

Question 31

global cycles examples

Answer 31

carbon, oxygen, sulfur, nitrogen cycling; atmospheric pool is global

Question 32

local cycles examples

Answer 32

phosphorus, potassium, calcium; minerals rather than gasses

Question 33

3 mechanisms for nutrient cycling

Answer 33

biological, geological, chemical

Question 34

nutrient budget components

Answer 34

• input (decomposition rates)
  -mean residence time
  -output

Question 35

carbon cycle: available forms

Answer 35

CO2 gas, organic matter, dissolved C in water

Question 36

carbon cycle: largest pool

Answer 36

sedimentary rocks

Question 37

carbon cycle: key processes

Answer 37

*photosynthesis/respiration
-net movement of C to ocean 0> ocean acidification
-fossil fuels -> C in atmosphere
-erosion of organic matter

Question 38

why does CO2 in the atmosphere increase in the northern hemisphere winter

Answer 38

less photosynthesis is being done to counteract respiration
*more land in northern hemisphere -> more photosynthesis; global pattern reflects northern hemisphere seasonality

Question 39

nitrogen cycle: major reservoir

Answer 39

atmosphere

Question 40

nitrogen cycle: available forms

Answer 40

NH3, NO2, NO3

Question 41

nitrogen cycle: key processes

Answer 41

bacteria break down N2 into available forms; nitrogen fixation

Question 42

Phosphorus cycle: main reservoir

Answer 42

rocks

Question 43

Phosphorus cycle: available forms

Answer 43

decomposers release avail form: (PO4) 3-

Question 44

Phosphorus cycle: key processes

Answer 44

weathering, decomposition

Question 45

how can phosphorus become unavailable

Answer 45

soluble P combines with Fe, Ca, Al through chemical mechanism -> forms insoluble unavailable nutrients

Question 46

nutreince limitation for plants: N and P patterns

Answer 46

N starts off all in the atmosphere (N NPP limitation) than rocks break down and P decreases (P NPP limitation)

Question 47

how to humans add excess nutrients into nutrient cycle

Answer 47

• phosphorus runoff -> eutrophication
  -fossil fuels, N fixing crops, N fertilizer -> N fixation adds N to atmosphere

Question 48

nitrogen saturation

Answer 48

nitrogen additions to an ecosystem lead to losses of the same order of magnitude; trees die

Question 49

how do humans remove nutrients from environment/cycles

Answer 49

• removing trees/vegetation(logging)
  -???