Energy and ecosystems Flashcards
In ecosystems what do plants synthesise organic compounds from?
- Atmospheric or aquatic carbon dioxide
What are most of the sugars synthesised by plants used as?
Respiratory substrates
What are the rest of the sugars synthesised by plants used for?
and what do they form?
To make other groups of biological molecules
- The biomass of the plants
What can biomass be measured in terms of?
In terms of mass of carbon or dry mass of tissue per given areas
Whats the chemical energy store in dry mass be estimated using?
Calorimetry
What does GPP stand for?
Gross primary production
What is GPP?
What is it given in?
The chemical energy store in plant biomass
- Given in area or volume
What does NPP stand for?
Net Primary production
What is NPP?
The chemical energy store in plant biomass after respiratory losses to the environment have been taken into account
What is the Equation for NPP?
NPP - GPP - R
What is NPP mainly available to the plant for?
Plant growth and reproduction
What is the NPP also sometimes available to?
give to examples
Other trophic levels in the ecosystem, such as herbivores and decomposers
What is N?
Net production of consumers
What can N be calculated by?
N = I (F + R) I = chemical energy store in ingested food F = chemical energy lost in faeces and urine R = respiratory losses to the environment
What is primary and secondary productivity? and how can it be measured?
Is the rate of primary or secondary production
- It’s measured as biomass in a given area in a given time
( kj ha-1 year-1 )
