High Confidence - Biodiversity Flashcards
How do you ensure a sample is not biased?
Use random sampling.
What process would you follow to ensure random sampling?
Divide the field into a grid using a tape measure.
Use a random number generator to select coordinates.
This ensures that each sample site has the same probability of being picked.
Bonus: Take samples at different times of the day and in different weather conditions.
If the investigator picks the samples, what is this called?
Opportunistic.
Note: Data will be biased.
Give examples of the equipment you would use for sampling.
Quadrat - Plants
Pitfall - Insects
Sweep net - Insects
Net - Aquatic
What should you ensure that you do when sampling to get good results?
Repeat the process to collect as many samples as possible.
Make sure your sample collection method is constant. E.g. leave pitfall traps out for the same length of time.
When counting samples - what should you be mindful of?
That organisms do not escape and you do not count them twice.
How do you calculate Simpson’s Index or Diversity?
n = total number of organisms in species
N = total number of all organisms
Note: the answer will always be between 0 and 1.
Explain the consequences of higher and lower diversity.
The higher the diversity of habitat, the greater the ability to cope with change is.
The lower the diversity, the more easily it will be damaged by change.
How does climate change affect global biodiversity?
Species are forced to migrate to more suitable areas. This changes species distribution. Increases biodiversity in one location decreases it in another.
If a species cannot migrate, it may die out.
Organisms that have a huge effect on the environment are called what?
What are two points that are often associated with them?
Keystone species
Relatively low population size
Often predators e.g. wolves
Sampling done at fixed intervals is called what?
Give an example of how you might achieve this.
Systematic sampling
Plant species in a field:
Quadrats placed on the ground along a transect. Starting from a shady corner going to the middle.
Define ‘biodiversity’
The variety of living organisms in an area.
What are the three levels of biodiversity?
Habitat diversity
Species diversity
Genetic diversity
Explain habitat diversity and provide examples.
The number of different habitats in an area.
Includes physical factors such as:
Soil
Temperature range
Living factors e.g. availability of food, presence of predators.
Examples:
Coastal area: beaches, sand dunes, mudflats, salt marshes
River valley: meadows, agricultural fields, streams, woodland
What would you look at to determine the species diversity of an area?
Number of different species (richness)
Abundance of each species (evenness)
