Human changes: Deforestation

Question 1

overview

Answer 1

Forests are cleared for agriculture, building, ranching, mining and commercial crops such as soya and palm oil. Large amounts of the above-ground biomass are burned releasing most carbon into the atmosphere. Forest clearing accelerates the decay of deadwood and litter, as well as below-ground organic carbon.

Question 2

Tropical regions

Answer 2

In tropical regions most of the remaining biomass decomposes in less than ten years. Deforestation is widespread across the world but is particularly concentrated in tropical regions, e.g. Indonesia. In total, deforestation accounts for about 20% of all global carbon dioxide emissions.

Question 3

overall

Answer 3

When deforestation happens by burning carbon is immediately released into the atmosphere. The forest becomes a carbon source rather than a carbon sink.

Deforestation removes a natural carbon store, reduces soil carbon content and closes down photosynthesis. The FAO estimate that about 13 million hectares of the world’s forest are cut down per year.