Ecology
Over the last nine pages we have been looking
at a number of individual, but not independent, components of
permaculture design. These were mostly components from the world
of nature. In the real world, all of the pieces, including humans,
work together to form a total, interrelated environment. Ecology
is the study of these 'total' landscapes or ecosystems.
The Elmwood Institute in California has published a list of Principles
of Ecology that are pertinent to permaculture design. These are
supplemented by quotes from the paper Great Ideas in Ecology by
Eugene Odum found in BioScience, 42:7, 1992.
Interdependence
All members of an ecosystem are interconnected in a web of relationships
in which all life processes depend on one another. The success
of the whole system depends on the success of its individual members,
while the success of each member depends upon the success of the
system as a whole.
Sustainability
The long-term survival (sustainability) of each species in an
ecosystem depends on a limited resource base. Each species has
its niche, or place, in the overall structure using a limited
segment of the food web and a portion of the space available for
nesting sites and raising of young.
Ecological Cycles
The interdependence among the members of an ecosystem involves
the exchange of matter and energy in continual cycles. These ecological
cycles act as feedback loops. The waste products of one group
may become the food source for another.
Energy Flow
Solar energy, transformed into chemical energy by the photosynthesis
of green plants, drives all ecological cycles. Energy is not lost,
but it is transformed as it moves through the system. "As
communities become larger they require more of the available energy
for maintenance." (Odum)
Partnership
All living members of an ecosystem are engaged in a subtle interplay
of competition and cooperation, involving countless forms of partnership.
There are "two aspects to the struggle for existence: organism
versus organism, which leads to competition, and organism versus
environment, which leads to mutualism." (Odum)
Flexibility
In their function as feedback loops, ecological cycles have the
tendency to maintain themselves in a flexible state, characterized
by interdependent fluctuations of their variables. "Short-term
interactions ... tend to be oscillatory or cyclic; ... large,
complex systems ... tend to go from randomness to order and will
tend to have more steady-state characteristics." (Odum)
Diversity
The stability of an ecosystem depends crucially on the degree
of complexity of its network of relationships; in other words,
on the diversity of the ecosystem. "The focus on preserving
biodiversity must be at the landscape level, because the variety
of species in any region depends on the size, variety and dynamics
of patches (ecosystems) and corridors." (Odum)
Coevolution
Most species in an ecosystem coevolve through an interplay of
creation and mutual adaptation. The creative reaching out into
novelty is a fundamental property of life, manifest also in the
processes of development and learning.
