Energy and Ecosystems Flashcards
1
Q
define biomass
A
the total mass of living material in a specific area, at a given time
2
Q
what is the process called to estimate the chemical energy in dry mass
A
calorimetry
3
Q
how is biomass measured
A
using dry mass per given area, in a given time
4
Q
describe how calorimetry works
A
- a sample of dry material is weighed
- then its burnt in pure oxygen in a sealed chamber
- the bomb is surrounded by a water bath
- the combustion causes a small temperature rise
- because we know how much energy is needed to heat 1g by 1c
- we can calculate the energy released
5
Q
why cant plants rely only on the sun for energy
A
- most of the suns energy is reflected back into space
- not all wavelengths can be absorbed
- light may not fall on a chlorophyll molecule
6
Q
what is meant by gross primary production (GPP)
A
the rate at which chemical energy is incorporated into organic molecules by an ecosystem
7
Q
what is meant by the net primary production (NPP)
A
the rate at which chemical energy is incorporated into organic molecules that make up the new plant biomass
