Tropical Rainforests - Water and Carbon

Question 1

General Rainforest Facts

Answer 1

Annual Rainfall: 2000mm+
Average Temperatures: 27 Degrees Celsius
Home to 200 million people and around half the world’s species of plants and animals
Rich biodiversity of plants and animals
Distinctive layers formed by plants, some trees reaching 45m heights
Absorb huge quantities of CO2 and emit 28% of the world’s oxygen

Question 2

The Water Cycle in the Rainforest

Answer 2

The dense forest canopy intercepts 75% of rainfall
About 25% of the rainfall evaporates
Of the 75%, half is used by plants, the other infiltrates into the soil (temporary storage or runoff)

Question 3

Rainforests - Carbon Cycle

Answer 3

Wood is about 50% carbon (rainforests act as carbon sinks).
Respiration (of plants, trees and animals) returns carbon dioxide to the atmosphere.
Decomposition occurs, with decomposer organisms (fungi, bacteria) thrive in wet and warm conditions - releases carbon dioxide into the atmosphere.
Some carbon is stored in soil, or dissolved and then removed by streams.

Question 4

The Indonesian Rainforest

Answer 4

As recently as the 1960s, 80% of Indonesia was rainforest, but rapid development has decreased the volume.
Just under half the original forest cover still exists.
Over a million hectares of Indonesian rainforest is cleared annually, 70% occurring in forests on mineral soils and 30% in carbon-rich peatland forests.
The rainforest has become a carbon source.
Indonesia is now the world’s third largest producer of carbon emissions - around 85% of its emissions are from deforestation and peatland degradation.
In 1997-98, carbon emission rates of the atmosphere reached their highest - there were many forest fires in Indonesia. Carbon-containing smoke particles (black carbon) were also released, causing haze and spreading air-pollution to nearby countries.
By the time the forest fires ended, an estimated 8 million hectares of land was burnt.
In 2015, over 10,000 fires burned over the Indonesian islands. The effects of El Nino exacerbated the effects, drying out damp peatland. Smoke affected health, and the volume of CO2 released was believed to be equal to the UK’s total annual emissions.