Ecology Essay Example | Topics and Well Written Essays - 2000 words

Ecology - Essay Example such as inorganic aspects (carbon, nitrogen, carbon dioxide, water), organic compounds (protein, carbohydrates, lipids), climatic factors (temperature, moisture, light, topography), producers (plants), macro consumers and micro consumers (Unit 3: Ecosystems, 2004, p.56). Ecosystem is maintained by cycling nutrients and energy derived from the external sources. There are three levels in the ecosystem, where the first trophic level consists of the primary producers, that is, some bacteria, algae and plants. The herbivores that feed on the primary source like plants comprise the second trophic level and the third trophic level consists of the predators that consume the herbivores. Furthermore, the ecosystem also consists of another group called decomposers, which include worms, insects, bacteria, fungi, molds etc that â€Å"breakdown† the dead decaying substances, thus returning the nutrients to the soil (Unit 4: Ecosystems, n.d., p. 8). The gross primary productivity (GPP) of an ecosystem is the total amount of organic matter produced through photosynthesis, whereas the net primary productivity (NPP) refers to the energy that is present for plant growth â€Å"subtracting’ the amount that plant uses for respiration (9). In order to conduct detailed analysis of the ecosystem, one must first have a clear idea about ecosystem boundaries. The whole earth can be considered as an ecosystem because all things interact with each on earth. The ecosystem â€Å"distributed† regionally and globally can be identified by the common basic structural form (2 – Ecosystems and Their Services, n.d., p. 51). According to the analysis done by MA (Mill ennium Ecosystem Assessment), â€Å"10 categories† were made, namely, forest, island, dryland, polar, coastal, marine, inland water, mountain, cultivated and urban. These categories on their own cannot be considered as an ecosystem, but each category consists of many ecosystems, and the characteristic feature of all ecosystems are highly