A12 BIODIVERSITY

What is the definition for habitat?

the environment in which an organism usually lives

What is the definition for population?

all the individuals of the same species living in a particular area

What is the definition for community?

all the individuals of all the species living together in the same area at the same time

What is the definition for species richness?

the number of different species in a community

What is the definition for biodiversity?

the number of different species and the number of individuals of each species within any one community

What is the equation for the diversity index?

What do all the letters mean in the diversity index equation?

d= species diversity index

N= total number of organisms of all species

n= total number of organisms of each species

What does a larger number for species diversity mean?

the greater the species diversity

What does a higher diversity mean for the stability of the ecosystem?

• more stable ecosystem

• with a wide variety of organisms its less likely that disease or change in climate will affect every organism

• this allows the ecosystem to continue to exist

Why is plant diversity so important?

• increased plant diversity

• more habitats

• more food sources

• so biodiversity increases

How does the removal of plants affect biodiversity?

• removal of plants reduces plant diversity

• less habitats

• less food sources

• so biodiversity decreases

How does farming reduce diversity?

• natural plants and animals are lost when the land is cleared, ploghed, reducing food sources and habitats

• growth of specific crops stops the growth of other species

• pesticides and herbicides may be used to kill unwanted species

• fertilisers are designed to encourage growth of specific crops

Why is it crucial to find the balance between biodiversity and profit?

• farming practices that maintain or increase biodiversity can be expensive, labour intensive and time intensive and may reduce the yield of crops and livestock

• this means the farmer will have to charge more from the produce

What’re advantages of hedges?

• increased biodiversity which increases in predators that eat pest species, so crop yield and profit would increase

• increase in pollinators so higher yield, so more profit

• may attract more tourists so increased profit

What’re disadvantages to hedges?

• reduces the area of land which can be used for crop growth, so decreases the yield and profit

• interspecific competition between crop species and other species so decreased yield and profit

• more difficult to farm as harder to access with machinery adn hedges need to be maintained so higher labour costs and reduced profit

• greater biodiversity so increased pest population, therefore decreased yield and profit