4: GENETICS - BIODIVERSITY Flashcards
(18 cards)
What is biodiversity?
the variety of different species in a specific area
What is a habitat?
where an organism lives
What is a community?
populations of different species in a habitat
What is species richness?
no. of different species in a community (doesn’t take into account the population size of each species)
What is species evenness?
the relative no. of individuals (populations) of the different species in a community
What is the index of diversity?
a measure of how diverse an area is
What is the equation for index of diversity?
D = N(N-1)/Σn(n-1)
(N is the total no. of organisms, n is the no. of individuals of each species found in an area)
What does a higher index of diversity mean?
the area is more diverse
What does a diversity index of 1 mean?
all individuals are the same species
What are some agricultural techniques that affect biodiversity?
- woodland clearance
- hedgerow removal
- pesticides
- herbicides
- monocultures
Woodland clearance:
- why is it done?
- how does it impact biodiversity?
- done to increase area of farmland
- directly reduces no. of trees and sometimes no. of diff tree species
- also destroys habitats so some species could lose their shelter and food source
- this means that species will die/be forced to migrate to another suitable area, further decreasing biodiversity
Hedgerow removal:
- why is it done?
- how does it impact biodiversity?
- done to increase area of farmland by turning lots of small fields into fewer, larger ones
- destroys habitats so some species could lose their shelter and food source
- this means that species will die/be forced to migrate to another suitable area, further decreasing biodiversity
Pesticides:
- what are they/why are they used?
- how does their use impact biodiversity?
- chemicals that kill organisms (pests) that feed on crops
- decrease diversity directly by killing pests
- also any species that feed on the pests will lose a food source so their no.s could decrease too
Herbicides:
- what are they/why are they used?
- how does their use impact biodiversity?
- chemicals that kill unwanted plants (weeds)
- decrease plant diversity
- could decrease no. of organisms that feed on the weeds
Monocultures:
- what are they?
- how does it impact biodiversity?
- when farmers have fields containing only 1 type of plant
- decreases biodiversity directly
- will support fewer organisms (eg: as a food source/habitat) which further reduces biodiversity
Why does there need to be a balance between agriculture and biodiversity?
- agriculture is important for producing resources we need from the environment (eg: food, fibres for clothing, medicines, fuels)
- biodiversity is important for maintaining the environment
What is done to try and achieve a balance between agriculture and biodiversity?
conservation schemes
What are some examples of conservation schemes?
- giving legal protection to endangered species
- creating protected areas which restrict further development including agricultural development
- the environmental stewardship scheme encourages farmers to conserve biodiversity (eg: replanting hedgerows and leaving margins around fields for wild flowers to grow)
