Animals in Agroecosystems - Agroecology: The Ecology of Sustainable Food Systems - page 278

their weight on the acorn diet, producing flesh used for the unique and highly sought-after ham they are famous
for ( jamón Ibérico ). Cattle prefer the green herbaceous growth of the winter months, and the sheep are able to do
well on the green biomass of winter as well as dry plant material that persists into the summer.
The Dehesa represents an example of the sustainable use of resources in a marginal environment. It is sustainable
only because its management is based on optimizing the natural productivity of the landscape through careful
management of livestock, not on maximizing yields. Its base is diversification, complementarity of plants and
animals, extensive rather than intensive use of the fragile natural resources of the oak forest, local animal breeds,
and management knowledge built up over centuries.
Competition from factory-farmed pork, the desire for higher returns per unit area of land, and the movement
of rural people to the cities, however, all put pressure on this remarkable system. An agroecological understanding
of its value is needed to preserve it into the future.

FIGURE 19.8 Iberian pigs. This locally adapted breed is the most important animal component of the Dehesa system in Spain.

contains many examples of research on animal-oriented
agroforestry systems that demonstrate many characteris-
tics of ecological sustainability and provide many eco-
nomic and social benefits as well.

fish or shellfish with crop production. As one might
expect, these systems are most common in areas with
abundant moisture, where wetlands would predominate in
the absence of agriculture.
Integrated rice and duck farming is practiced in parts
of Japan and China (Furuno, 2001). Weeds and insects are
consumed by the ducks, manure from the ducks is returned
to fertilize the rice, and humans harvest both ducks and rice
at the end of the crop cycle. When the aquatic fern Azolla,

Aquaculture and Crop Production

A variety of systems in use around the world incorporate
the raising of either waterfowl or aquatic species such as