think of living organisms in terms of an organization with various levels
of structure. Ecology is the study of the patterns and relationships of
these systems. The word "oikos" means "house" in Greek
and "logos" means "pattern." The word "oecologie"
was coined by Ernest Haeckel, German scientist and follower of Darwin,
in 1866. Since then and throughout the 1890's European botanists studied
systems of plants and land and their interdependencies, giving rise to
the science of ecology. Thus the science of ecology has always had a holistic
approach top nature, connecting communities and systems. The philosophical
roots of ecology and the land ethic of Aldo Leopold are discussed in detail
in the unit on Ethical Systems.
study of ecology was tilted towards moral philosophy. As a science, it
grew in parallel, more as a description of the distribution of plant communities,
and their patterns of succession. In the 1920's and '30's ecology became
more of a discipline of science. In 1927, Charles Elton, a colleague of
Aldo Leopold, coined phrases such as "food chain" and "niche"
and began to work on the way nutrition started with the sun, and on the
natural dependencies of organisms and "communities of plants."
The English ecologist Arthur Tansley, reflecting that the land community
was anthropomorphic, proposed "ecosystem" for the system of
discussion describes each of the main levels, however it does not go all
the way back to the most minute level of cells and genes. These structured
levels are terminology that you need to be familiar with to start discussing
the role of ecology in environmental issues.
living and nonliving components of an area that includes the habitat and
the physical and chemical environment. The classic definition of an ecosystem
was stated in 1953 by Odum: any unit that includes all organisms (i.e.,
community) in a given area interacting with the physical environment so
that a flow of energy leads to a clearly defined structure, biotic diversity,
and materials cycles. The point is that a balance is reached.
A particular group of the same organism that depends on an optimum range
of each environmental factor such as light, pH, nutrients, food, water,
competitors, predators, etc. These ranges should overlap within a particular
location. Some of these environmental factors are more critical than others.
several members of the same species in a particular area at the same time
and genetically distinct from other populations of that species.
different species interacting together, forming a distinct system that
includes the food web. Note that the habitat is where the community lives.
For example, a wetlands habitat is defined as an area often covered by
shallow water, or one where the ground is wet long enough to support plants
specialized to grow under saturated conditions.
several habitats together in a particular climatic area e.g. tropical
rainforest versus coniferous rain forest.
highest organizational level in which life exists that ranges from several
thousand meters into the atmosphere, and to depths of the oceans including