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)
Explain genetic diversity and provide examples.
The variation of alleles within a species.
Example:
Human blood type - controlled by 3 different alleles.
Variation of alleles in a dog species creates different breeds.
Why would you use non-random sampling?
If there is a lot of variety in the distribution of species/types of areas in the habitat and you want to make sure that different species and/or areas are sampled.
What is stratified sampling?
When different areas in a habitat are identified and sampled in proportion to their part of the habitat as a whole.
What other considerations should you have in mind when preparing a biodiversity investigation.
Risk assessment
Damage to the environment e.g. trampling
Disturbing animals
Ethical issues - animal distress
What are the ecological reasons for protecting biodiversity?
Organisms in an ecosystem are interdependent.
Protect species
The loss of just one species could:
- Disrupt the food chain
- Disrupt nutrient cycles e.g. worms numbers decline - soil quality deteriorates. Growth of plants and the amount of food available.
Maintain genetic resources
Define species’ evenness?
The number of individuals in each different species.
What is polymorphism?
A locus that has two or more alleles.
These genes exist in a population where there are many variations of a gene present.
What could you look at to measure genetic diversity?
How would you calculate this?
The proportion of polymorphic gene loci in a population.
number of polymorphic gene loci
total number of loci
x 100 to convert the proportion to a percentage
Human population growth decreases biodiversity.
What are the 4 factors of this?
Provide examples for each.
HOUP!
Habitat Loss
Humans need land for housing and food production
e.g. Amazon deforestation for grazing and agriculture
Over-exploitation
Increased demand for resources, therefore, used up quicker. Food, water and energy.
e.g. Industrial fishing depletes certain fish species. Can cause extinction.
Urbanisation
Cities and roads isolate species. Populations are unable to interbreed which decreases genetic diversity.
Pollution
Population growth increases waste. Pollutants can kill species and destroy habitats.
e.g. Fertilizer flowing into rivers, gases from factories and cars cause acid rain. pH of rivers, lakes and soils lowered.
Feeding a large population requires what?
Why does this lead to?
Monoculture - the growing of a single variety of a single crop.
Habitat loss
Land cleared for large fields. Marine fish farms.
e.g. Mangrove forests being cleared for shrimp farms.
Loss of local plants and animals
Cleared away with pesticides and herbicides.
e.g. Herbicides on US corn farms kills Milkweed plant. The main source of food for the Monarch butterfly.
Loss of heritage varieties
Traditional varieties of crops do not make enough money.
Give some examples of genetic resources.
Food and drink
Clothing
Cotton, Silk, Leather
Drugs
Morphine from poppies
Fuels
Organisms used to produce biofuels (ethanol, biogas)
Industrial materials
Wood, paper, dyes, oils, rubber
Why are genetic resources important for the future?
The genes may allow us to engineer crops that are resistant to changes in growing conditions. E.g. drought-resistant crops
How can monoculture have an economic impact?
Continuous monoculture causes soil depletion because the nutrients are gradually used up. This means increased spending on fertilizers and decreased yields.
What are the two types of conservation?
In situ
Ex Situ
What is in situ conservation?
Protecting species in their natural habitat.
