Ecosystems Flashcards
What’s a pioneer species?
The species/ organisms that arrive first that are adapted to abiotic factors (have a low biodiversity)
What’s a climax community?
Species that arrive last that are adapted to biotic factors (have a high biodiversity)
What’s a climax community?
The species that arrives last and is adapted to biotic factors (has a high biodiversity)
What’s meant by decomposition?
The break down/ conversion of organic matter to inorganic
What’s meant by denitrification?
The conversion of nitrates to nitrogen
What’s nitrogen fixation?
Conversion of nitrogen into ammonia
What’s nitrification?
Conversion of ammonia into nitrite
What are biotic factors?
Living conditions within a habitat
What are abiotic factors?
Non-living conditions within a habitat
What’s meant by ‘biomass’?
The chemical energy store for an organism
What’s used by plants to create biomass?
Organic molecules
What piece of equipment is used to measure biomass?
Calorimeter
The mass of carbon is usually about … the dry mass
…Half…
What’s the dry mass?
The mass of an organism after water has been removed
What’s Gross Primary Production (GPP)?
The chemical energy stored in plant biomass, in a given area/ volume
What’s respiratory loss?
The amount of GPP lost as heat during respiration
What’s Net Primary Production?
The chemical energy stored in a plant biomass after respiratory losses
(NPP = GPP - R)
What’s Net Production of consumers?
Production of new biomass by consumer
How can net production of consumers be calculated?
N = I (F + R)
- N= net production of new biomass by consumers.
- | = chemical energy stored in ingested food.
- F = chemical energy lost to the environment in faces and urine.
- R = chemical energy used in respiration.
How can efficiency of energy transfer be calculated?
Total energy consumed / net productivity x 100
What are saprobionts?
Microorganisms that feed on dead/ decaying organic matter
What’s extracellular digestion?
When sabrobionts secrete enzymes onto dead organic matter
What’s the chemical symbol for nitrate ions?
NO3-
What’s the chemical symbol for nitrite ions?
NO2-
What’s the chemical symbol for ammonium ions?
NH4+
How can carbon leave the atmosphere?
By mixing with water vapour and falling as acid rain via precipitation
What’s combustion?
The burning of biomass/ fossil fuels to release carbon dioxide
Are artificial fertilisers organic or inorganic?
Inorganic
Are natural fertilisers e.g., manure, organic or inorganic?
Organic
What’s leaching?
When water soluble plant nutrients are lost from the soil
Ways to maximise primary productivity in farming:
- Using pesticides
- Maximise plant exposure to light
- Irrigation to maximise water supply
Ways to reduce energy loss in secondary productivity:
- Antibiotics
- Restrict movement of animals
- Heating in barns
What’s succession?
Change in an ecosystem over time
When does secondary succession take place?
When parts of an ecosystem are disturbed and remnants of previous community remain
What happens to the soil as pioneer species die?
It becomes more nutrient-rich and stable/ less hostile
What’s deflected succession?
Where ecosystems are disturbed by humans, so succession can’t take place
What’s positive chemotaxis?
Movement towards a chemical stimulus
What’s the definition of a producer?
Organisms that photosynthesise to make their own food (autotrophs)
What’s the definition of a consumer?
Organism that eats other organisms
What’s the definition of trophic levels?
Stage in a food chain
What is ecology?
The interactions between organisms and their environment
