core practical 10 Flashcards
What is abundance in ecological studies?
The number of individuals of a particular species in a specific area.
What is distribution in ecological studies?
The pattern of where a species is found in a habitat.
What is a quadrat?
A square frame used to sample and estimate populations of immobile organisms.
What is percentage cover?
The proportion of the quadrat covered by a species, useful for plants and immobile organisms.
What is systematic sampling?
A sampling method where measurements are taken at regular intervals, often used with transects.
What is a transect?
A line across a habitat along which systematic sampling is conducted.
What is the independent variable in a population investigation using quadrats?
The location where the quadrats are placed (e.g., distance from a tree, or along a transect).
What is the dependent variable in a quadrat investigation?
The number of individuals or percentage cover of a species in each quadrat.
What are some control variables in a quadrat sampling investigation?
Size of the quadrat
Number of quadrats used
Time of sampling
Weather conditions
Why is random sampling important in ecology?
It reduces bias and ensures the sample is representative of the habitat.
How can you randomly place quadrats?
By using random coordinates generated before sampling.
When should systematic sampling be used instead of random sampling?
When investigating how abiotic factors influence distribution along an environmental gradient.
What are the steps for using quadrats to estimate population size?
- Choose a sampling area.
- Place quadrats randomly or systematically.
- Count the individuals of each species in the quadrat.
- Repeat for multiple quadrats.
- Calculate mean number per quadrat and estimate total population.
How is percentage cover estimated in a quadrat?
By counting how much of the quadrat is covered by a species—more than half-covered means it is counted.
How can transects be used to investigate distribution?
By placing quadrats at regular intervals along a line from one area to another (e.g., from a riverbank to a dry field).
How can pH be measured in a habitat?
By using a pH probe or chemical indicator tests.
What tool can measure soil moisture?
A soil moisture meter.
How is light intensity measured in an ecological study?
Using a light meter.
How can wind speed be recorded in a field study?
By using an anemometer.
What is a kite diagram used for?
To show the abundance and distribution of species along a transect.
Why should the same sampling technique be used when comparing different habitats?
To ensure results are comparable and not affected by variations in methodology.
