Biodiversity Flashcards
Examples of how to avoid loss of biodiversity
Breeding programmes by zoos
Establishing of national parks
Re introduce species
Setting up seed banks
How can we predict the possible effects of climate change etc?
Computer programs
What is sampling?
Studying a large area by taking a small sample of its area to study the biodiversity. The whole area is to large to study
In terms of sampling, what points must be considered?
The sample area must be typical of the whole area
The bigger the sample area, the better, small areas are less likely to be typical
Method of sampling must not affect the results (animals might be scared away of human presence)
What method do scientists use as sampling is not completely accurate?
Statistical analysis
It takes into account of sample size
What is a quadrat?
A square frame used to sample a measured area
Explain process of using quadrat
Square frame placed randomly in the area to be studied. Individuals of different species in each quadrat are counted and recorded. They are placed randomly so person placing them doesn’t introduce any bias
What is a transect?
Set of samples taken down a set line marked by a chain or tape. Samples are taken at measured intervals and the species under the sampling point are recorded.
What is the purpose of transects?
Used to measure how populations change along some sort of gradient.
(Difference between light and shaded part of woodland)
What is biological control?
The use of living organisms to control the population of a pest species
What are control agents?
Usually predators, parasites or micro organisms that cause death by disease
What is biological control an alternative of?
Chemical control. The use of chemical pesticides to kill pests
Why is a control agent introduced?
To reduce a pest problem, it is always a species not already present in the environment.normally a species from a different country
Alien species
Advantages of biological control?
No chemicals are used which may persist on crops and enter food chain
The control agent will just attack the pest species. Chemical pesticides affect many species
Reduces the pest population to manageable level, rather than wiping out completely. This makes a more stable Eco system
Disadvantages of biological control
More complicated to operate than chemical control
Difficult to use outdoors. Containing the agent is difficult. Mainly used in greenhouses
More expensive than chemical control
Agent may cause problems in ecosystem
