Stratification: Layering of forests, particularly evident in temperate deciduous forests and tropical rainforests.
Tropical Rainforests: The natural vegetation found in the tropics, well suited to the high temperatures and heavy rainfall associated with those latitudes.
Leaching: The dissolving and removal of nutrients from the soil, typically very effective in tropical rainforests on account of the heavy rainfall.
Primary (Virgin) Rainforest: Rainforest that represents the natural vegetation in the region, unaffected by the actions of people.
Deforestation: The cutting down and removal of forest.
Clear Felling: Absolute clearance of all trees from an area.
Selective Logging: The cutting down of selected trees, leaving most of the trees intact.
Slash and Burn: A form of subsistence farming in tropical rainforests involving selective felling of trees and clearance of land by burning to enable food crops to be planted.
Selective Management System: A form of sustainable forestry management adopted in Malaysia.
Ecotourism: Nature tourism usually involving small groups with minimal impact on the environment.
Debt Relief: Many poorer countries are in debt, having borrowed money from developed countries to support their economic development. There is a strong international pressure for developed countries to clear these debts - this is debt relief.
Carbon Sink: Forests are carbon sinks because trees absorb carbon dioxide from the atmosphere. They help to address the problem of global carbon emissions.
Non-Governmental Organisation (NGO): An organisation that collects money and distributes in to needy causes, e.g. Oxfam, ActionAid and WaterAid.