LW-Glossary

Key terms for this unit:

Stratification: layering of forests particularly evident in temperate deciduous forests and tropical rainforests

Pollarding: cutting off trees at about shoulder height to encourage new growth

Sustainable management: a management approach that conserves the environment for future generations to enjoy as it is today

Tropical rainforests: the natural vegetation found in the tropics, well suited to the high temperatures and heavy rainfall associated with these 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 action 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 practised in tropical rainforests involving selective felling of trees and clearance of land by burning to enable food crops to be planted

Ecotourism: nature tourism usually involving small groups with minimal impact on the environment

Debt relief: many poorer countries are in debt, havig borrowed money from developed countries to support their economic development. The is 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 warming

Non-governmental organisation (NGO) - an organisation that collects money and distributes to it needy causes, e.g. Oxfam, ActionAid and WaterAid

Subsistence farming: farming to produce food for the farmer and his/her family only Hunter-gatherers: people who carry out a basic form of subsistence farming involving hunting animals and gathering fruit and nuts

Commercial farming: farming with the intention of making a profit by selling crops and/or livestock

Salinisation: the deposition of soild salts on the ground surface following the evaporation of water

Ecosystem: the living and non-living components of an environment and the interrelationships that exist between them

Biomes: global-scale ecosystems

Adaptations: the ways that plants evolve to cope with certain environmental conditions such as excessive rainfall

Producers: organisms that obtain their energy from a primary source such as the sun

Consumer: organisms that obtain their energy by eating other organisms

Food chain: a line of linkages between producrs and consumers

Food web: a diagram that shows all the linkages between producers and consumers in an ecosystem

Scavengers: organisms that consume dead animals or plants

Decomposers: organisms such as bacteria that break down plant and animal material

Nutrient cycling: the recycling of nutrients between living organisms and the environment Temperate deciduous forest: forests comprising broad-leaved trees such a oak that drop their leaves in the autumn.