energy transfer in agriculture ecosystems N/C

Question 1

agriculture ecosystem

Answer 1

ecosystems that are made up largely of domesticated animals and plants used to produce food for mankind

Question 2

why are agriculture ecosystems necessary

Answer 2

• energy lost when moving to higher trophic levels
• humans are at the third or fourth trophic level in the food chain
• this means that humans only receive a small proportion of energy necessary from food
• agriculture ecosystems try to ensure that as much of the available energy from sun is transferred to humans
• this increases the productivity of the human food chain

Question 3

productivity

Answer 3

the rate at which something is produced

Question 4

gross primary productivity (GPP)

Answer 4

the chemical energy store in plant biomass in a given area or volume, in a given time

Question 5

units of GPP

Answer 5

kJ m^-2 year^-1

Question 6

respiratory losses

Answer 6

chemical energy used for respiration

Question 7

net primary productivity (NPP)

Answer 7

the chemical energy store in plant biomass after respiratory loss (R) has been taken into account

Question 8

equation for NPP

Answer 8

NPP = GPP - R

Question 9

what factors affect NPP

Answer 9

• efficiency at which plants photosynthesise
  this can be improved by providing all necessary conditions for photosynthesis
• the area of ground covered by the leaves of the crop

Question 10

basic differences between natural and agricultural ecosystems

Answer 10

• energy input

- productivity