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
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The latter characteristic is less noticeable in countries with high population densities where a higher energy yield from arable crops is required, for example the necessity for widespread rice growing in Bangladesh.

Diversity and richness of plant species is with few exceptions lower in agro-ecosystems than in natural ecosystems. By the nature of farming it is far more efficient in terms of harvesting time and bulk sale to grow monocultures of a single plant species and to remove the diversity of weeds and pests that threaten crop yield. Furthermore, the initial clearing of land for farms removes a large majority of varied native species. Hence, in agro-ecosystems the remaining soil fauna, microorganisms, and any surviving weeds provide the only species diversity. For example in the U.K a wheat crop will only support the insects or animals (i.e. field mouse) that feed on wheat, and any species that can then feed on these primary consumers. Some non-native crops such as rape have very few consumers, and so support an even lower diversity of fauna. Also, the initial loss of the oak tree canopy and rich vegetation has removed the habitat for most bird species, like the jackdaw and tawny owl, and for small mammals such as the dormouse and
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