Ecosystems Flashcards
Ecosystem
All living and non-living factors in an area
Environment
All factors in a habitat which affect an organism
Habitat
An area occupied by an organism
Community
All living factors in an area
Population
All members of one species in a habitat
Niche
An organisms role in an ecosystem
Food chain
The sequence of organisms in which each is food for the other
Producer
First in the food chain ( plant )
Trophic level
A feeding level in a food web
Biomes
Major ecosystems with similar climates
Energy Transfer in Ecosystems
- Energy enters an ecosystem by photosynthesis in a producer’s biomass.
- Energy is passed on when another organism eats the producer
Why is not all of the energy passed on?
- Some of the plants do not retain all of the light energy
- It’s reflected, the wrong wavelength or passes through the leaf
- Some parts of plants and animals cannot be eaten or digested and are left in the waste
Net Productivity
Amount of energy available for the next level
Net productivity equation
GPP - Respiration
Efficiency
Energy in next level / Energy in the previous level * 100
Abiotic and Biotic factors
- Abiotic - Non-living factors
- Biotic - Living factors
Abiotic factors affect the abundance
A population’s size will vary depending on the amount of light, water, space or temperature around them.
Abiotic factors need to benefit the organism so it can grow and reproduce successfully
Biotic factors affect the abundance
- Competition: Competition within or outside a species can occur. When resources become limited eg: food, mates or space the population will compete to survive
- Predation: When a predator kills its prey the population is affected. As one population changes the other is affected too
- Disease: Diseases can affect the growth and size of populations
Measuring Abiotic factors
Using Equipment like :
- Thermometer
- Light sensor
- PH paper or sensor
- Compass
- Clinometer
What are the different sampling methods?
- Random sampling
- Quadrats and transects
Random Sampling
- Reduces bias
- Throwing a quadrat randomly in an area
- Counting how many species are in each square
Transects
Line transect - Use a tape measure in a line
Measure how many species touch the tape next to it
Succession Defenition
This is the gradual change of an ecosystem over time
Primary Succession
This occurs in newly formed rock or in the sand where no species live and barely any nutrient content
Secondary Succession
This occurs on land where soil still remains eg: after a forest fire
Pioneer species
First species to arrive and colonise an area.
- They tolerate harsh conditions
- Fast growing but are then out-competed
- Create humus, and add nutrient content to the soil
- Have low diversity
Climax community
The final stage in succession, where constant biodiversity is reached and a complex community of organisms remains.
Succession can be prevented by human activity
Human interaction can prevent succession. If humans constantly disturb the area or alter the land then succession can be slowed.
