Flashcards in Productivity In Ecosystem Deck (23)
Give 2 uses of the sugars made in plants.
Give the units for biomass
grams per cm2 per year
Mass per area per year
Name the technique used to estimate biomass.
Give a definition of gross primary productivity (GPP).
Chemical energy stored in plant biomass in a given area/volume in a given time.
How is net primary productivity calculated?
Gross primary productivity - respiratory losses.
NPP = GPP - R
Which term NNP or GPP represents the amount of energy available to the other tropic levels?
How is net productivity of consumers (N) calculated?
N = I - (F + R)
I = injested, F= faeces R= repsiration
Give 3 ways in which farmers can increase productive in crops.
Reduce competition (eg remove weeds)
Reduce damage by pests (eg use pesticides/ biological control)
Give 3 ways in which farmers can reduce respiratory losses in animals.
Reduce space / movement / muscle contraction
Keep animals warm (less food used to maintain body temperature).
Quality / easily accessible nutrients
Wheat --> human
Wheat --> chicken --> human
Which food chain is more efficient at transferring energy to humans?
Wheat --> human
Remember energy is lost from food chain at each tropic level.
Give 3 biologically important molecules that contain phosphate.
Proteins / amino acids
RNA / DNA
Give 3 biologically important molecules that contain nitrogen.
Amino acids / proteins
DNA / RNA
Saprobiotic nutrition - what is it?
Extra cellular digestion by fungi / bacteria causing decomposition
What happens during ammonification?
Organic molecules --> ammonia
Eg protein in dead plant/animal converted to ammonia
What happens during nitrification?
Ammonia oxidised to nitrites.
Nitrites oxidised to nitrates
What happens during nitrogen fixation?
Nitrogen is oxidised to nitrate
What happens during denitrification?
Nitrate converted to nitrogen.
What are mycorrhizae?
A mutalistic relationship between fungi and plant roots.
What is the advantage of mycorrhizae?
Increases uptake of water / inorganic ions by plant roots.
Increases surface area in contact with soil.
Why are fertilisers added to soil?
Increases inorganic ions in soil.
Inorganic ions not a factor limiting plant growth.
Prevents deficiency symptoms in plants.
Arable farming reduces the amount of inorganic ions in the soil. Why?
Crop/plants removed at harvest.
What happens if fertilisers are added to the soil?
Leaching - fertiliser enter water system.
Bacterial populations increases.
Bacterial respiration reduces amount of oxygen in water.
Suffocation of aquatic animals.