7. Agriculture And Biodiversity Flashcards
What are farmers aim ?
Maximise amount of food they can produce from a given area of land.
Woodland clearance
Increase the area of farmland
Reduces number of trees and Nd can reduce different tree species.
Species forced to die or migrate elsewhere.
Reduction in biodiversity
Hedgerow removal
Increase area is farm land
Turns lots of smaller files into fewer larger ones.
Destroys habitats as species lose shelter / food source.
Reduces biodiversity
Pesticides
Kill organisms that feed on crops
Reduces diversity by directly killing pests.
Species that feed on pests with lose food source
Herbicides
Kill unwanted plants
Reduces plants diversity
Reduce number of organisms that feed on them
Monoculture
Farmers have fields containing only one type of plant
Single type of plant reduce biodiversity directly and will support fewer organisms
Example - study done in the uk
Found that insect species fell during years when agriculture practices where intensified and land was used to grow cereals
And then bird diversity fell
Why do we need agriculture
Food
Fibres for clothing
Medicines
Fuels
Why is biodiversity so important
It’s helps maintain environment.
Provides us with new sources of food and medicines
Benefits agriculture.
Give some example of conservation schemes
Legal protection to endangered species.
Protected areas like SSSI - restrict development
Environmental stewardship scheme encourages farmers to conserve biodiversity - replanting hedgerows
What stat test do you use to see weather there’s a correlation between 2 variables or not ?
Spearman’s tank correlation co efficient
Spearman’s rank
-1 or +1
Result of test is a number between -1 and +1
-1 then there is perfect negative correlation between 2 variables.
+1 perfect positive correlation
0 weak correlation
What does a positive correlation mean in spearman’s rank ?
As one variable increases so does the other.
What does a negative correlation mean?
As one correlation increases the other decreases.
Null hypothesis
Always suggests that there is no correlation between the factors.
Results of SR allow you to see if null hypothesis can be rejected or accepted
