Ecology Flashcards
What are the 4 levels of ecological organisation
Individual organism
Population
Communities
Whole ecosystem
What is interdependence
All organisms in an ecosystem depend upon each other. If the population of one organism rises or falls, then this can affect the rest of the ecosystem
What is competition
Plants compete for light, water, space and minerals
Animals compete for food, mates and territory
Competition can be interspecific or intraspecific
What is an ecosystem
The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment
What are 7 abiotic factors
- Light intensity
- Temperature
- Moisture levels
- Soil pH and mineral content
- Wind intensity and direction
- Carbon dioxide levels for plants
- Oxygen levels for aquatic animals
What are 3 biotic factors
- Availability of food
- New pathogens
- One species out competing another so the numbers are no longer sufficient to breed
What are the producers of biomass for life on Earth
Photosynthetic organisms
What are the 4 Trophic levels
Producer - Photosynthesises to produce glucose
Primary consumer - Eats producer
Secondary consumer - Eats primary consumer
Tertiary consumer - Eats secondary consumer
In a stable community the numbers of predators and prey rise and fall ……
In cycles
Belt transect practical method (6 Marks)
1 - Extend a measuring tape from one side of the habitat to another.
2 - Place a quadrat at 0m on the tape.
3 - Count the numbers/estimate percentage cover of each species.
4 - Use a key to identify each species.
5 - Record results in a table.
6 - Move the quadrat along the measuring tape.
Quadrat random sampling method (6 Marks)
1 - Divide the area to be sampled into a grid using measuring tapes placed at right angles to each other.
2 - Use random numbers to generate coordinates within the grid on which to place the quadrats.
3 - Place a quadrat at each coordinate.
4 - Count the numbers/estimate percentage cover of each species in each quadrat.
5 - Use a key to identify each species.
6 - Record results in a table.
7 - Calculate the average of each species
Explain the importance of the carbon and water cycles to living organisms
Maintaining this carbon balance allows the planet to remain hospitable for life
What does the carbon cycle do?
The carbon cycle returns carbon from organisms to the atmosphere to be used by plants in photosynthesis
Explain the role of microorganisms in cycling
materials through an ecosystem by returning carbon to the atmosphere as carbon dioxide and mineral ions to the soil.
Microorganisms help return minerals and nutrients back to the environment so that the materials can then be used by other organisms.
The effect of water availability on the rate of decay
With little or no water there is less decomposition because decomposers cannot survive
Without water, enzymes that decompose biological material cannot be excreted