Topic 7 - Bio diversity Flashcards
What are the advantages of biological control
No chemicals are used, there fore no bio accumulation
Will only attack the specific targeted pest
It doesn’t kill all the pests so is better on the whole for the environment than other methods
What is biological control?
The use of a living organism to control a pest
What is an alien species
An animal or plant that has been introduced into a country that it does not originate from
What are the problems that come with alien species
The alien species may grow faster than the native species and cause upset to the natural ecosystem
The native species may not be able to compete against the alien species
Compete against and existing species natural to the area to the point it dies out
What is biodiversity
The number of different species in a given habitat
What is a quadrat ?
A square used to count the number of species inside of it, or the percentage of plant cover
What is a transect
A series of quadrat samples taken in a line
Explain how you would use a transect in an experiment
A tape measure of rope is laid out across the area to be sampled. Quadrats are then placed at regular intervals
How do you ensure accuracy of sampling with a transect
The sample must be typical of the whole area
Use a bigger sample area
How do you find out how many organisms there are in an area ?
Select a random sampling area. This avoids bias
Place a quadrat randomly and count the number of living organisms are within the quadrat
Repeated at least twice
Calculate an average
what is the method of capture and recapture
Capturing a number of individuals from the same species
And marking them then release them back into the wild
Some time later, capture a number of the same species in the same area.
Analyse which of those had been captured the first time by identifying the marks on them.
Use an question to work out the total number of that species in that area
What are the problems/ disadvantages of capture and recapture technique
Immigration
Predation may have reduced numbers of the species
Same size may be too small to produce accurate results
What are habitats being destroyed for in the world?
Building
Agriculture
Dumping rubbish
What are the methods of protecting bio diversity
CITES SSSI Captive breeding programme National parks Seed banks
What are the disadvantages of biological control?
Predator may become the pest
There is a delay in between introducing the predator and a reduction of the pest
Often difficult to use outdoors
