Factors effecting biodiversity 11.6

Question 1

why is maintaining biodiversity essential for perceiving a balanced ecosystem

Answer 1

As species are interconnected within an ecosystem, the removal of one species can have a profound effect on others. For example it could lead to a loss of another species food source of shelter

Question 2

what is the leading cause of loss of biodiversity

Answer 2

humans

Question 3

What are the main problems that occurs due to human activity

Answer 3

• deforestation
• Agriculture (monocultures)
• climate change

Question 4

How can deforestation affect biodiversity

Answer 4

• if one species of tree is felled reduces species diverisity
• reduces habitats and food sources for animals which can cause reduced species eveness and richness
• if animals migrate other areas biodiveristy may increase

Question 5

How can agriculture affect biodiveristy

Answer 5

• deforestation, to increase the area of land available for growing crops or rearing animals
• removal of hedgerows,
• use of chemicals
• herbicides are used to kill weeds.
• monoculture

Question 6

How can removal of hedgerows affect biodiveristy

Answer 6

As a result of mechanisation, farmers remove hedgerows to enable them to use large machinery to help them plant, fertilise and harvest crops. It also frees up extra land for growing crop growing. This reduces the number of plant species present in an area and destroys the habitat of animals such as blackbirds, hedgehogs, mice and many invertebrates

Question 7

How can the use of chemicals affect biodiversity

Answer 7

Use of chemicals such as pesticides and herbicides. Pesticides are used to kill pests that would eat the crops our live on the animals. This reduces species diversity directly as the pest species and indirectly by destroying the food source of other organisms

Question 8

How can the use of herbicides affect biodiversity

Answer 8

Herbicides are used to kill weeds. A weed is any plant growing in an area where it is not wanted. Weeds are destroy as they compete with the cultivated plants for light, minerals and water. By destroying weeds, plants diversity is reduced directly and animal diversity may also be reduced by the removal of an important food source

Question 9

How can a monoculture affect biodiveristy

Answer 9

Many farms specialise in the production of only one crop, with many acres of land being used for the growth of one species. This has an enormous local effect in lowering biodiversity as only one species of plant is present. As relatively few animals species will be supported by only one type of plant, this results in low overall biodiversity levels. The growth of vast oil palm plantations is one of the leading causes of rainforest deforestation, leading to a loss of habitat for critically endangered species like the rhino

Question 10

what are some of the key climate change findings

Answer 10

• the warming trend over the last 50 years is nearly twice that for the previous 100 years
• The average amount of water vapour in the atmosphere has increased since the 1980s over land and ocean.
• The average temperature of the global ocean down to depths of 3 km has increased
• the global average sea level rose by an average of 1.8 mm per year from 1961 to 2003
• average artic temperatures have increased at almost twice the global average rate in the past 100 years
• long term upwards trends in the amount of precipitation have been observed over many regions from 1900 to 2005

Question 11

If global warming continues biodiversity will be affected in what ways

Answer 11

• The melting of the polar ice caps could lead to the extinction of few plant and animal species living in these regions. Artic are migrating further and further north to find favourable conditions as their habitat shrinks. Increasing global temperatures would allow temperatures plant and animal species to live further north than currently
• Rising sea levels from melting ice caps and the thermal expansion of oceans could flood low-lying land, reducing the available terrestrial habitats. Saltwater would flow further up rivers, reducing the habitats of freshwater plants and animals living in the river and surrounding areas
• Higher temperatures and less rainfall would result in some plant species failing to survive, leading to drought-resistant species becoming more dominant.
• Insect life cycles and populations will change as they adapt to climate change. Insect are key pollinators of many plants, so if the range of an insect changes, it could affect the lives of the plants it leaves behind, causing extinction.