Sampling and Food Security Flashcards
Define sampling.
Taking observations or measurements from a small area, which is representative of a larger area.
Give 5 examples of sampling techniques/methods.
Posters, Pitfalls Traps, Sweep Nets, Kick Sampling, Tree Beating.
How does tree beating work?
A large white cloth is stretched out underneath a tree while said tree is shaken or beaten to dislodge invertebrates, which will fall onto the cloth.
Why do pitfall traps have to have rooves?
Without a roof, the trap could fill up with rainwater and drown any invertebrates inside.
Which sampling technique would you use to collect sample data for the number of diving beetles in an area?
Kick Sampling - diving beetles will be underwater.
Outline the process of kick sampling.
Kick a riverbank or bed to disturb mud and vegetation. Hold a net downstream to capture any organisms released into the flowing river.
What are the two main types of identification key?
Branched/Spider Key and Numbered/Dichotomous Key
What is the formula for estimating total population using the capture-recapture method?
Total population number = first sample size x second sample size/number of recaptured individuals
What are the advantages and disadvantages of random sampling?
A: It prevents bias.
D: The data collected may not be representative of the while population, as the area has not been chosen according to trends.
What is a quadrat and why is it useful?
A quadrat is a square frame divided into a grid used for marking out areas to take sample data from.
How do you work out the total population number from sample data taken from a quadrat?
Multiply the mean population per m2 by the total area.
What is used to study how the distribution of organisms changes over a gradient?
A transect.
Define biodiversity.
A measure of how many different species live in an ecosystem.
How does deforestation reduce biodiversity?
-Permanent removal of species’ habitat.
-Removes food sources and shelter.
-Affects predator species as their prey grows in scarcity.
What is the process of eutrophication and what causes it?
Eutrophication is caused by runoff from farmlands containing pollutants such as fertilisers flowing into rivers, causing an algal bloom. This algal bloom prevents sunlight from reaching the organisms beneath the river’s surface, meaning that the plants below shall die and microorganisms start to decompose them. Microorganisms respire as they decompose the plants, which requires oxygen; therefore the oxygen levels fall and kill other organisms (such as fish) living in the river, until nothing but algae lives.
What is growing only one crop in an area referred to as?
Monoculture.
How does monoculture affect biodiversity?
Very few species are supported by just one type of plant, so an abundance of that plant and little else cannot sustain a healthy, diverse ecosystem.
Give 4 ways in which biodiversity can be lost.
Deforestation, Hunting and Fishing, Agriculture, Pollution.
Give three ways in which agriculture reduces biodiversity.
- Herbicides used to kill plants growing in particular areas reduces the number of plant species present as well as the number of animal species present, as it can remove sources of food or shelter.
- Pesticides reduces the number of pest species and thus decreases the food source for predator species. It can also accumulate in a food chain, killing animals that were not targeted.
- The removal of hedgerows removes habitats and decreased the number of plant species.
What is the key word for: “Protecting a natural environment to ensure that habitats are not lost?”
Conservation.
Give a 6 examples of conservation methods.
-Protected habitats for species to live in
-Education to increase awareness of the problem
-Captive breeding in zoos to increase the population
-Seed banks to store the seeds of rare plants (E.G. Seed Bank in Kew Gardens)
-Artificial ecosystems made to replace destroyed ones
-Legal protection to stop hunting and trade.
What are coral reefs and rainforests both examples of?
Areas with high biodiversity.
Give three ethical reasons for maintaining biodiversity.
- No human has the right to cause extinction.
- Stewardship - humans have a moral duty to protect the environment.
- All organisms have a right to life.
Give four economic reasons for maintaining biodiversity.
- Technology often utilises the assets of living creatures - biomimicry.
- Plants give humans medicine.
- Tourists enjoy nature probably
- Resources. We require a variety of crops for food and fuel.