Ecological Relationships And Energy Flow Flashcards
Define biodiversity
A measure of the number of the different species living in an area
Define population
The number of organisms of the same species living in an area
Define habitat
Where a population lives
Define environment
An organisms surroundings. It contains factors that influence the organism. These factors can be divided into abiotic and biotic.
Define community
Several populations of different species living in habitats close together
Define ecosystem
An area where a community of organisms live and are affected by a range f environmental factors
What is an abiotic factor
Non living factors e.g temperature
Define biotic factors
A living factor e.g a predator
Name abiotic factors
Wind speed
Water / soil moisture
Light
Temperature
pH levels
How does wind speed affect organisms
It affects the rate of water loss by plants and therefore affects their survival rates in exposed areas.
How does water / soil moisture affect organisms
It’s measured by finding mass difference between the wet soil and it being dried out. Affects survival and therefore distribution of plants and animals.
How does light affect organisms
Measured using a light meter. Affects the survival and therefore distribution of plants as they light to photosynthesise.
How does temperature affect organisms
Messier with thermometer. Affects rate of cell reactions like photosynthesis and diffusion.
How does pH affect organisms
Measured using soil test kits or probes. The pH of soil is very important in distribution of many plants. Some plants will only grow in relative acid soils or relative alkaline soils. But most plants prefer to grow in neutral pH.
What are the biotic factors for animals
Competition between
Food
Water
Territory
Mates
What are biotic factors between plants
Competition between
Light
Water
Minerals
Space
What is a quadrat
A square frame used to measure a sample of an area.
Why are quadrants used
To investigate the distribution of organisms in a habitat
What makes a quadrat investigation reliable
A large sample needs to be obtained. For example 20 small sections should be sampled for a large area
Define representative
It needs to be representative of the entire area being investigated. In other words sampling should take place randomly across the larger area, not just concentrated in one part.
What is the method for quadrat random sampling
- Divide the area to be sampled into a grid using tape measures placed at right angles to each other.
- Use random number generator to generate coordinates within the grid to place the quadrat.
- Place quadrat at each coordinate
- Count the numbers / estimate percentage cover of each species in each quadrat.
- Use a key to identify each species
- Record results in a table.
- Calculate the average of each species.
What is a belt transect
It’s a method that is used when there is a gradual change from one side of a habitat to another, like the change in light between the outer edges of a forest to the centre.
What is the method for the belt transcet
- Extend a measuring tape from one side of the habitat to another
- Place a quadrat at 0m on the tape
- Count the numbers / estimate percentage of each species.
- Use a key to identify each species.
- Record results in a table.
- Continue this up the tape measure until the end
- Calculate average of each species
- A bar chart can be drawn to who the data obtained.
Define energy flow
The transfer of energy between organisms in a food chain
What is a producer in a food chain
A plant which absorbs sunlight creating its own energy.
What is a food chain
A food chain describes the order in which energy passes through living organisms.
Why is the sun important for food chains
It is the initial source of energy for all food chains
Define producer
A producer makes food by photosynthesis
What is a consumer
A consumer feeds on other living things
What is a food web
A food web shows how a number of food chains are interlinked. They are more realistic because very few consumers feed on only one thing.
What do arrows represent in a food chain
Arrows show the direction of transfer of substances (e.g carbon and nitrogen) through a food chain as well as showing what eats what (consumption)
And energy flow