Books

Ecology: A Bridge Between Science and Society

by E P Odum

Agroecosystems are domesticated ecosystems that are many basic ways intermediates between natural ecosystems and fabricated ecosystems.

Differences: solar powered but auxiallary sources enhance productivity, diversity is greatly reduced in order to maximise yield of specific products, dominant plants and animals under artificial selection, control is external and goal orientated rather than internal via subsystem feedback, extensive dependence and impact on externals, autotrophic rather than heterotrophic, increased power density ratio.

Ecology per se will not solve probles (eg world food shortages) but the holistic and system-level approaches that underlie ecological theory can make a contribution to the integration of disciplines.

Traditionally, the land-owning farmer is an efficient controller since he is able to respond and adjust to local conditions and needs.

His goal is not only to make a living but also to pass on his farm to the next generation in as good or better shape. (also an internal controller since he operates within the farming system.

Unfortunately..control has passed to more distant controllers, absentee landlords, corporations, government, and especially the grain and food markets..

These remote controllers cannot respond effectively to the nurmerous positive and negative feedbacks that originate within the crop system itself.

Furthermore, the goal of the remote controllers is priamrily directed to obtaining the largest possible yield of a cash crop, not to maintaining long-term prodcutivity. Landholder