Forests : Glossary

There are 40 documents in this section.

  • Fauna

    16 March 2001

    The animal life characteristic of a particular biome. The savanna biome, for example, supports large populations of herbivores, such as wildebeest, antelope and kangaroo, and predators in the form of lions, cheetahs, hyenas and dingoes that prey on them. Any change in a biome, whether natural or human-induced, has the potential to alter the associated fauna.

  • Endangered species

    16 March 2001

    Species of plants or animals threatened with extinction because their numbers have declined to a critical level as a result of overharvesting or because their habitat has drastically changed. That critical level is the minimum viable population (MVP), and represents the smallest number of breeding pairs required to maintain the viability of species.

  • Ecology

    16 March 2001

    Originally defined by Ernst Haeckel in 1866, ecology is the study of the relationships that develop among living organisms and between these organisms and the environment.

  • Conservation (nature)

    9 March 2001

    Protection against irreversible destruction and other undesirable changes, including the management of human use of organisms or ecosystems to ensure such use is sustainable.

  • Global warming

    22 August 2000

    The idea that increased greenhouse gases cause the Earth's temperature to rise globally.

  • Greenhouse effect

    22 August 2000

    The cause of global warming. Incoming solar radiation is transmitted by the atmosphere to the Earth's surface, which it warms. The energy is retransmitted as thermal radiation, but some of it is absorbed by molecules of greenhouse gases instead of being retransmitted out to space, causing the temperature of the atmosphere to rise. The name comes from the ability of greenhouse glass to transmit incoming solar radiation but retain some of the outgoing thermal radiation to warm the interior of the greenhouse. The 'natural' greenhouse effect is due to the greenhouse gases present for natural reasons, and is also observed for the neighbouring planets in the solar system. The 'enhanced' greenhouse effect is the added effect caused by the greenhouse gases present in the atmosphere due to human activities, such as burning of fossil fuels and deforestation.

  • Greenhouse gases

    22 August 2000

    Molecules in the Earth's atmosphere such a carbon dioxide (CO2), methane (CH4) and CFCs which warm the atmosphere because they absorb some of the thermal radiation emitted from the earth's surface.

  • CFC's (Chlorofluorocarbons)

    21 August 2000

    A group of chemicals containing chlorine (Cl), fluorine (F) and carbon (C), sometimes referred to by their trade name Freon. These synthetic compounds were used extensively for refrigeration and aerosol sprays until it was realized that they destroy ozone (they are also very powerful greenhouse gases) and have a very long lifetime once in the atmosphere (more than 100 years). The Montreal Protocol agreement of 1987 has resulted in the scaling down of CFC production and use in industrialised countries.

  • Ecological balance

    21 August 2000

    Stability in an ecosystem achieved through the development of equilibrium among its various components. This does not imply that the community is static. It is subject to natural variations associated with ecological succession and other influences such as fire, disease and climate change, but the system is normally sufficiently elastic to make the necessary adjustments without major displacement of the balance. Human intervention that includes the introduction or removal of plants and animals, pollution of the environment and destruction of habitat is now a main cause of imbalance in many ecosystems.

  • Agroforestry

    12 August 2000

    The treatment of trees as an agricultural cropto provide for the planned production of fuelwood, timber,animal fodder and food. Agroforestry may also involve theintegration of tree cultivation into existing or planned agricultural activities.