3.4.6 Biodiversity Flashcards
Define biodiversity.
Variety in the living world
What is species diversity?
The number of different species and the number of individuals of each species within any one community
What is genetic diversity?
The variety of genes possessed by the individuals that make up a population of a species
What is ecosystem diversity?
The range of different habitats within a particular area
Define community.
All of the individuals of all species in a given habitat
Define population.
All of the individuals of one species in a given habitat
What is an ecosystem?
A specific area with a specific community and environmental conditions
How is species diversity measured?
N(N-1) / En(n-1)
N- number of organisms of all species
n- number of organisms of each species
E- the sum of
What impact does agriculture have on species diversity?
Reduced
A field can only support a certain amount of biomass
Farmers plant crops with desirable species
Other species have to compete but there is little space
Pesticides also reduce the amount of other plants so theirs don’t have to compete
What is the effect of intensive food production?
Reduced variety in habitats
So reduced species diversity
What can directly remove habitats?
Removal of hedgerows
Creating monocultures (one crop)
Draining ponds/marsh
Over-grazing of land
What can indirectly remove habitats?
Use of pesticides
Absence of crop rotation
What techniques can be used to increase species and habitat diversity?
Maintain hedgerows at beneficial height and shape
Plant hedges instead of fences
Maintain ponds
Plant native trees
Reduce pesticide use
Use organic rather than inorganic fertilisers
