Energy and Ecosystems Flashcards
1
Q
What is an ecosystem?
A
Abiotic and biotic factors
2
Q
How can biomass measured?
A
- Dry mass of tissue per unit area
- Mass of carbon
3
Q
How to measure dry mass?
A
- A sample is dried (oven) at low temp. The sample is continuously weighed at regular intervals until it becomes constant
4
Q
What is the mass of carbon?
A
About half the mass of dry mass
5
Q
What is Gross primary production?
A
- The total amount of chemical energy converted from light by plants in a given area
6
Q
What is respiratory loss?
A
- Heat lost to the environment when plants respire
7
Q
What is Net primary production?
A
- Energy available to the plant for growth and reproduction, stored in the biomass
- The energy available to organisms at the next stage in the food chain
8
Q
The equation for NPP
A
NPP = GPP - R
9
Q
Equation for net production
A
N = I - (F + R) N = Net production I = Chemical energy in ingested food F = Chemical energy lost in faeces R = Energy lost through respiration
10
Q
How to maximise energy transfer ?
A
- Simplifying food webs
- Reducing respiratory loss
11
Q
What is biomass?
A
The chemical energy store for an organism
12
Q
What is primary productivity?
A
- Rate of primary production by green plants
13
Q
What is secondary productivity?
A
- Rate of secondary production by consumers
14
Q
How can you maximise primary productivity
A
- Maximise light exposure
- Using warmer temps in glasshouses
- Irrigation to maximise water supply
15
Q
How do fertilisers improve primary productivity?
A
Maintain nutrient levels in the soil as they help plants convert energy to biomass efficiently
