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| Sunday, 16 January 2005 |
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Junior Observer |  |
| News Business Features Editorial
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Ecosystems of the world An ecosystem is a living community of plants and animals sharing an environment with non-living elements such as climate and soil. The most familiar natural ecosystems are our backyards or parks near our homes.
The world has many different ecosystems. Each one has its own climate, human activities, plants and animals. Very few ecosystems are natural because of human activities. Most ecosystems are under threat today than ever before, and need protection. Within each ecosystem, there are habitats which may also vary in size. A population is a group of living organisms of the same kind living in the same place at the same time. All the populations interact and form a community. The community of living things interacts with the non-living world around it to form the ecosystem. The habitat must supply the needs of organisms, such as food, water, temperature, oxygen and minerals. If the population's needs are not met, it will move to a better habitat. Two different populations cannot occupy the same niche (place) at the same time.
All ecosystems are 'open' systems, in the sense that energy and matter are transferred in and out. The Earth as a single ecosystem constantly converts solar energy into various organic products and has increased in biological complexity over time. There are a number of ecosystems on which life on Earth most heavily depends on. The agro-ecosystem ( the farms where we grow our food and livestock production systems), forest ecosystems (woodland), freshwater ecosystems (lakes, streams and rivers), grassland ecosystems (meadows, prairies, savannas), coastal ecosystems (beaches, reefs), urban ecosystems (even cities and suburbs are ecosystems) are some of the examples of such ecosystems. The goods and services that ecosystems provide us with, form the foundation of our economies. Agriculture, forestry and fishing are responsible for 50 per cent of all jobs worldwide. In 25 per cent of the world's nations, crops, timber and fish still contribute more to the economy than industrial goods. Ecosystems also purify our air and water, help to control our climate and produce services that can't be replaced at any cost. It is our very reliance on ecosystems that is threatening them. As our populations grow and consumption of food, water and other material needs increase, the ecosystems that provide these needs are abused and in some cases destroyed. Humans have affected ecosystems in almost every way imaginable! Everytime we walk out in the wilderness or bulldoze land, we are altering an ecosystem. We have disrupted the food chain, the carbon cycle, the nitrogen cycle and the water cycle. Mining minerals also takes its toll on an ecosystem. We need to do our best not to interfere with these ecosystems and let nature take its toll. **** What is a biome? A biome is a large area with similar flora, fauna and micro organisms. Most of us are familiar with the tropical rainforests, tundra in the Arctic regions and the evergreen trees in the coniferous forests. Each of these large communities contain species that are adapted to its varying conditions of water, heat and soil. For instance polar bears thrive in the Arctic, while cactus plants have thick skin to help preserve water in the hot desert. |
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Ecosystems, which vary in size can be as small as a puddle or as large
as the Earth itself. An example of a small scale ecosystem is a pond. A
medium scale ecosystem could be a forest. The tropical rainforest is an
example of a very large ecosystem, which is also known as a biome.
Ecosystems are dynamic entities composed of the biological community
and the abiotic environment. An ecosystem's abiotic (air, water, rocks,
energy) and biotic (plants, animals and micro organisms) composition
structure is determined by the state of a number of interrelated
environmental factors. Changes in any of these factors will result in
dynamic changes to the nature of these systems.
