B7 Deforestation and Land Use (page 93) Flashcards
Trees and Peat Bogs trap what?
traps carbon dioxide and lock it up
(the problems start when it escapes)….
What do Humans us land for?
lots of purposes like:
Building,
Quarrying,
Farming,
Dumping Waste.
When humans use lots of land, this means there’s less land available for what?
other organisms.
Sometimes, the way we use land has a bad effect on the environment, give example?
if it requires deforestation or the destruction of habitats like peat bogs and other areas of peat.
What do Deforestation mean?
it is the cutting down of forests (chopping down trees).
Why is Deforestation is done on a large-scale? (such as cutting down rainforests in tropical areas)
To clear land for farming (e.g. cattle or rice crops) to provide more food.
To grow crops from which biofuels based on ethanol can be produced.
Why can Deforestation cause many problems?
Less carbon dioxide is taken in.
Cutting down loads of trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced.
Apart from carbon dioxide not being removed from the atmosphere when trees are cut down, trees also ‘lock up’ some of the carbon that they absorb during photosynthesis in their wood, what do this mean?
trees can remove carbon from the atmosphere for hundreds of years, so removing trees means that less carbon is locked up.
What do it mean if more CO2 is in the atmosphere?
more CO2 causes global warming (see page 92), which leads to climate change.
When Deforestation happens, trees are burn to clear the land, what happens regarding the carbon dioxide?
carbon dioxide is released when trees are burnt (carbon in wood doesn’t contribute to atmospheric pollution until it’s released by burning).
when Microorganisms feed on bits of dead wood from deforestation, what to they release?
microorganisms release carbon dioxide as a waste product of respiration. (so more carbon dioxide is in the atmosphere).
What happens with Biodiversity with Deforestation?
Biodiversity (page 91) is the variety of different species - the more species, the greater the biodiversity.
Habitats like forests can contain a huge number of different species of plants and animals, so when they are destroyed there is a danger of many species becoming extinct - biodiversity is reduced.
What are Bogs?
they are areas of land that are acidic and waterlogged.
Why dont plant that live in bogs fully decay when they die?
because there’s not enough oxygen. The partly-rotted plants gradually build up to form peat. (pete bogs)
So the carbon in the plants is sotred in the peat instead of being released into the atmosphere.
Why are Peat Bogs often drained?
it so that the area can be used as farmland, or the peat is cut up and dried to use as fuel. It’s also sold to gardeners as compost. (peat is being used faster than it forms).
