11.6

Question 1

How have humans influenced biodiversity?

Answer 1

• Increasing human population means we need more space for housing and infrastructure and farming therefore disrupting the ecology of many areas
• Road developments isolates species meaning populations are unable to interbreed and gene flow cannot occur so genetic biodiversity is reduced
• Pollution from industry can kill species reducing habitat and species biodiversity

Question 2

What are the problems associated with this?

Answer 2

• deforestation- permanent removal of large areas of forest to provide wood for building and agriculture
• Agriculture- an increasing amount of land has to be farmed in order to feed the growing population. This has resulted in large amounts of land being cleared or instead plant one type of crop (monoculture)
• Climate change- release of CO2 and other pollutants into the atmosphere from the burning of fossil fuels is increasing global temp

Question 3

What is deforestation and how does this reduce biodiversity?

Answer 3

• can occur naturally for example as a result of forest fires or caused by lightening or extreme heat and dry weather
• If only a specific type of tree is felled, the species biodiversity is reduced
• Can also be destroyed indirectly such as acid rain which results in pollutants being released into the atmosphere

How does this reduce biodiversity?

• directly reduces the number of trees in an area
• Species diversity is reduced
• Reduces or removes other animals food source
• Animals have to migrate to other areas to ensure survival

Question 4

How does agriculture affect biodiversity?

Answer 4

• creating enough space for farming leads to deforestation which reduces biodiversity
• farmers often select the most high value crops or crops that will have a high yield which can greatly reduce the biodiversity of an area
• farmers would want to grow lots of this species since it is economically viable
• This results in a reduction of biodiversity for example
• Deforestation- to increase land available for growing crops or rearing animals
• Removal of hedgerows to allow farmers machinery to help plant, fertilise and harvest crops while also freeing up more land. This results in the loss of species such as blackbirds and destroys the habitat of many species
• Using chemicals such as pesticides and herbicides that kill insects which indirectly removes the food source for the other species
• Herbicides are used to kill weeds which compete with plants for soil minerals and water which reduces plant diversity and potentially remove a food source for other animals
• Monoculture- lowers biodiversity as only one species of plant will be present or loss of habitat for some animals

Question 5

What has climate change result in? And how does this affect biodiversity?

Answer 5

• CO2 levels in the atmosphere have significantly increased since the industrial revolution
• average amount of water vapour in the atmosphere has increased
• Average temperature of global ocean has increased
• Global sea level average has rose
• Average artic temperatures has increased
• Mountain glaciers and snow cover have declined on average
• Insects population can change due to climate change, they can also migrate to new areas and spread new diseases

How will global warming affect biodiversity?

• melting polar ice caps leads to the extinction of animal and some plant species
• Animals migrate further north in the artic to find more favourable conditions as their habitat shrinks
• Rising sea levels due to melting ice caps and thermal expansion
• Drought resistant xerophytes become more dominant over other plant species
• Insects