The Differences between Natural Ecosystems and Agro-Ecosystems

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The Differences between Natural Ecosystems and Agro-Ecosystems

An ecosystem is by definition the processes and interactions of the

biotic community (living organisms) and inorganic component (physical

and chemical features) of a particular environment. In a natural

setting a stable, or climax ecosystem represents a state of natural

equilibrium, whereby all occupant species compete for resources, and

energy and nutrient cycles are balanced. Human farmers effectively

out-compete most natural species for resources, and through select

harvested species export energy and nutrients for consumption

elsewhere; this is an agro-ecosystem or plagioclimax.

An ecosystem unaffected by man has a structure characteristic of its

climatic region, for example deciduous oak woodland in the U.K has a

typical biomass of 30Kgm-2, and an average productivity of 1.2Kgm-2

per year. This reflects the maximum mass of flora and fauna that can

be supported by the climate and soil. However, when such woodland is

cleared and tilled by man new characteristics appear. Arable crops

have a far lower average biomass, wheat is typically 1.6Kgm-2, with

productivity falling to 0.6Kgm-2 per year. This is caused by the loss

of the multi-storey vegetation that photosynthesises at maximum scale

and optimum rate, and in arable fields there is not the habitat to

support faunal species such as woodpeckers and other woodland birds,

resulting in lost animal mass. Livestock farmland is characterised by

similar primary productivity as grassland, but again this is far below

the potential for the temperate climate and fertile soils. In

addition, livestock farming results in a far grea...

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...at may lead to global warming.

It could, however, be argued that with the exponential growth of the

human population intensive agriculture in the long-term reduces the

rate at which new areas of land have to be cultivated, effectively

reducing the need for extensification and environmental damage.

However, the opposing argument suggests that if farming was not only

extensified, but also made sustainable, then the positive ecological

gain would outweigh the loss of some natural habitats. Technology has

provided few suggestions as to how intensive productivist agriculture

could be replaced, and the protest against GM crops is narrowing down

current alternatives. The impact of modern farming on the environment

is certainly damaging, but it provides a tangible and potentially

successful solution to the worlds hunger.

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