Ecology - Humans and biodiversity

Question 1

Biodiversity =

Answer 1

the variety of all the different species of organisms on Earth or within a specific ecosystem.

Question 2

Why does high biodiversity ensure the stability of an ecosystem?

Answer 2

It reduces the dependence of one species on another in the ecosystem for food or habitat maintenance.

Question 3

Ways in which biodiversity is maintained to make up for the damage humans have already made:

Answer 3

• breeding programmes in zoos for endangered species
• protecting and regeneration of rare habitats
• reintroduction of hedgerows in agricultural areas where single crop species are grown, as hedges provide habitat for many organisms
• recycling resources rather than dumping waste in landfill

Question 4

What are hedgerows and why are they good for biodiversity?

Answer 4

1. habitat connectivity:
   - hedgerows link fragmented habitats allowing wildlife to move between isolated patches of forest, grassland etc.
2. food and shelter:
   - offer a variety of resources like buds, flowers, pollen, fruits, leaves, and plant sap, providing sustenance for many species. They also provide shelter, nesting sites, and winter quarters for diverse animal populations.
3. reduce flooding
   - absorb water
4. help control crop pests, reducing the need for pesticides
5. store carbon:
   - store carbon and help combat climate change

Question 5

What are peat bogs?

Answer 5

Bogs are very wet areas of land without trees in which many types of moss grow. They are acidic and often have very low levels of nutrients. Here
decomposition is very slow and peat is formed from partially decayed plants.

Question 6

Why are peat bogs being destroyed?

Answer 6

1. to produce garden compost
2. drainage of peatlands to make them more productive for agriculture or forestry is a significant driver of destruction, as it leads to peat decomposition and the release of stored carbon.

Question 7

Why are peatbogs being destroyed bad?

Answer 7

1. release locked up carbon - bad for the environment
2. This dramatically reduced
   biodiversity. Because peat takes such a long time to form, it is a
   non-renewable energy resource like fossil fuels.

Peat bogs are a very important store of carbon. We call them
carbon sinks. If all the peat was removed and burned this would quickly release a huge volume of carbon dioxide into the atmosphere and contribute to the greenhouse effect.

Question 8

Why had deforestation increased and why is it bad?

Answer 8

• large amounts of carbon released into the atmosphere due to combustion
• extinctions and reductions in biodiversity as habitats are destroyed
• climate changes, as trees absorb carbon dioxide and release water vapour

Large-scale deforestation in tropical area has been carried out to provide land for cattle and rice fields, and to grow crops for biofuels.