Agricultural Ecosystems
Since the change of the agricultural production, there has been both positive and negative effects, with regards to the environment and the economy. New technologies, government policies, increased chemical use and the mechanisation of the farming world have all favoured maximizing crop production. There have, however been some significant costs. Topsoil depletion, groundwater contamination, decline of family farms, increased costs of production and reduction of species diversity.
The energy loss at each trophic level has meant that the energy humans receive is only a small percentage of the total amount of energy available to the sun as humans are most often the third or fourth trophic level in a food chain. Intensive farming practices have tried to ensure that as much of this energy as possible is transferred, thus increasing the productivity of the human food chain.
eg. Grass Cow Human
Arable
Natural ecosystems and agricultural ones differ mainly in the energy input and the productivity. In natural ecosystems, the sun is the sole source of energy and much of the land would be covered by forests if it were allowed to develop naturally, known as the climax community. This community is obtained through succession, in which simple communities are replaced by much more complex ones. Each successive community harbors many other life forms, and therefore having a great species diversity, for example, the desert and tropical rain forests are such climax communities. In order for the agricultural ecosystem to have a high productivity,