Delhi Public School Varanasi


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Ecosystem: Definition

A major threat to sustainable ecosystems and biological diversity is agriculture's continued reliance on high-risk pesticides. Every year US agriculture introduces into the environment over 900 million pounds of pesticides in producing food and fiber consumed worldwide. While contributing to the production of an abundant and affordable food supply, continued reliance on pesticides, comes at a cost in terms of harm to people, wildlife and the environment.

An ecosystem is a system whose members benefit from each other's participation via symbiotic relationships (positive sum relationships). It is a term that originated from biology, and refers to self-sustaining systems

An ecosystem can be viewed as a system where the relationships established across different industries become mutually beneficial, self-sustaining and (somewhat) closed. This is clearly the case for Silicon Valley with the entrepreneurial industry, the venture capital industry needed to fund the entrepreneurial industry, and Stanford University, supplying the human capital needed to develop innovative/creative ideas and technologies. The goal of this ecosystem is to generate entrepreneurial ventures. Once an ecosystem is established, and is able to take first-mover advantage, it becomes very difficult for other regions to emulate. The region exhibits network effects and is able to establish lock-in since the switching costs associated with moving to another region are prohibitive. The collective costs of many moving out of the region (i.e. if another region tried to incentivize a large move) would be prohibitive. Thus current members have a clear incentive to remain, and new would-be entrepreneurs, venture capitalists and students interested in this industry have a significant incentive to relocate to this region.An ecosystem consists of a community of organisms and the non-living factors that influence them. The living and non-living elements interact to support and maintain a balance between plant and animal communities within the ecosystem.

Energy Flow Through the Ecosystem

The diagram above shows how both energy and inorganic nutrients flow through the ecosystem. We need to define some terminology first. Energy "flows" through the ecosystem in the form of carbon-carbon bonds. When respiration occurs, the carbon-carbon bonds are broken and the carbon is combined with oxygen to form carbon dioxide. This process releases the energy, which is either used by the organism (to move its muscles, digest food, excrete wastes, think, etc.) or the energy may be lost as heat. The dark arrows represent the movement of this energy. Note that all energy comes from the sun, and that the ultimate fate of all energy in ecosystems is to be lost as heat. Energy does not recycle!!

The other component shown in the diagram are the inorganic nutrients. They are inorganic because they do not contain carbon-carbon bonds

To summarize: In the flow of energy and inorganic nutrients through the ecosystem, a few generalizations can be made:

The ultimate source of energy (for most ecosystems) is the sun
The ultimate fate of energy in ecosystems is for it to be lost as heat.
Energy and nutrients are passed from organism to organism through the food chain as one organism eats another.
Decomposers remove the last energy from the remains of organisms.
Inorganic nutrients are cycled, energy is not.

For further details visit:- www.bbc.co.uk