Factors affecting biodiversity

Question 1

Why is maintaining biodiversity important?

Answer 1

Essential for preserving balanced ecosystem for all organisms.

Species interconnected within ecosystem.
—> Removal of 1 species = profound effect on another.

Question 2

What are 3 factors that affect biodiveristy?

Answer 2

Human population growth

Agriculture

Climate change

Question 3

Describe the 3 factors:

Answer 3

• Human population growth:
  –> need to create enough space for housing, industry + farming .: deforestation
• Agriculture:
  increased amount of land must be farmed to feed growing population.
• Climate change:
  Release of greenhouse gases + burning of fossil fuels = increases global temperature.

Question 4

Describe how deforestation affects biodiveristy?

Answer 4

• Directly reduces number of trees present in an area.
• Only specific type of tree grown = species diversity reduced.
• Reduces number of animal species present in area.
• Animals forced to migrate to other areas to ensure survival –> can result in biodiveristy of neighbouring habitats increasing.
• Soil errosion -> reduce crop yield

Question 5

Describe how agriculture affects biodiversity:

Answer 5

• Deforestation : increase land to rear animals/ grow crops
• Removal of hedgerows: enable use of large machinery to help plant/fertilise/harvest crops. –> Reduces number of plant species
• Use of chemicals (pesticides/herbicides) –> reduces pest species + indirectly destroys food source of other organisms.
• Herbicides used to kill weeds –> plant diveristy reduced.
• Monoculture –> production of only 1 crop –> many acres of land used for growth of 1 species.

Question 6

What does global warming mean?

Answer 6

Rise in Earth’s mean surface temperature.

Greenhouse gases trapping more thermal energy in the atmosphere.

Question 7

How will biodiversity be affected if global warming continues?

Answer 7

• Melting of polar ice caps –> lead to extinction of few plants/animal species
• Rising sea levels + thermal expansion of oceans could flood low-lying land –> reducing available terrestrial habitats.
• Higher temperatures + less rainfall –> result in some plant speices failing to survive –> lead to drought-resistant species (xerophytes) = more dominant.
• Insect life cycles + populations will change as they adapt to climate change –> key pollinators –> can cause plant 😵

Question 8

How can species still survive with climate change?

Answer 8

Climate change = slow, species have time to adapt.

e.g: change to different food source/migrate to new areas

Question 9

What are the aesthetic reasons for maintaining biodiveristy?

Answer 9

• Presence of different plants/animals in environemnt to enrich lives
• Provides inspiration for people (artists)
• Studies show patients recover more rapidly from stress + injury when supported by plants

Question 10

What are the economic reasons for maintaining biodiversity?

Answer 10

• Biodiveristy rich areas = attractive = promote ecotourism
• Greater diveristy = greater potential to manufacture different products in future.
  –> beneficial to humans
• Increases crop yield
• Drug development

Question 11

What are the ecological reasons for maintaining biodiveristy?

Answer 11

• Genetic biodiveristy
• Organisms interdependent on others for their survival.
  —> Removal of 1 species = significant effect on other species .
• Keystone species = maintain structure of ecological community.

Question 12

Example of keystone species:

Answer 12

• Sea stars = predators
• Eat mussels + sea urchins

If not eaten = growing populations crowd coral reefs

Question 13

Human activity versus biodiversity?

Answer 13

Farming, grazing, planting of hedges = +ve change in landscape