If asked to define a forest, most of us will straightaway think of trees.
While it is true that trees dominate - they are the biggest organisms present there, there are many of them, and they don't move about - a forest is in fact a community of not just plants and animals, but of micro-organisms as well.
Throw into the mix the non-living, abiotic components like soil, climate and water, and take in the complex interrelationships among the organisms and the environment, and we are closer to an actual understanding of this ecosystem.
Over two-thirds of known terrestrial species
Over 30% of the Earth's surface is covered with forests. They are among the most notable storehouses of biological diversity on the land - they house over two-thirds of known terrestrial species; they also harbour the largest share of threatened species.
Forests and Humans
Forests have a variety of uses to humans, including wood from trees, nutrition from animals, for grazing, recreation, medicinal and so on.
At the present time, conservationists are still arguing about a 'technical' definition of a forest. According to The Food and Agriculture Organisation of the UN (FAO), a forest does not stop being a forest just because the trees are gone.
While that may be so, it is important to understand how the disappearing green cover and the resultant threat to habitats and to human life fits into the bigger picture of life on the planet.
The forest ecosystem
The forest is a complex ecosystem - a biological system with distinct, myriad interrelationships of the living part of the environment (plants, animals and micro-organisms) to each other and to the non-living, inorganic or abiotic parts (soil, climate, water, organic debris, rocks).
Picture it as an intricate web - fragile but at the same time holding the ecosystem together.
Forest variety and distribution
Forests come in all sizes and types - from the northern taiga to the scrub forests of arid regions to the rainforests of the humid tropics.
They are found on moving glaciers¹ , in fresh and salt water, on arctic mountain slopes. They do not occur in isolation from the rest of the landscape. The type of forest in a given area depends on many elements, including climate, soil, water source, rainfall patterns, seed sources and human influence.
The complex ecological relationships involving forests could allow humans to benefit from them in a variety of ways. However, a deeper understanding of these relationships is crucial for development of effective forest management and policy options.
-----------------------------------------------¹Source: Forest ecosystem by Bernard T. Bormann, Judy L. Meyer, Tim Schowalter, Everett Hausen. McGraw-Hill Encyclopedia of Science & Technology.
