The word “Ecology” was coined by a German biologist in
1869 and is derived from the Greek word, “Oikos” meaning
“House”.
Ecology is the branch
of science that deals with the
study of interactions between living organisms and their physical
environment. Both are closely inter-related and they have
continuous interaction so that any change in the environment
has an effect on the living organisms and vice-versa. Any unit
of biosystem that includes all the organisms which function
together (biotic community) in a given area where they interact
with the physical environment is known as ecosystem.
study of interactions between living organisms and their physical
environment. Both are closely inter-related and they have
continuous interaction so that any change in the environment
has an effect on the living organisms and vice-versa. Any unit
of biosystem that includes all the organisms which function
together (biotic community) in a given area where they interact
with the physical environment is known as ecosystem.
The ecosystem is the functional unit in ecology as it consists
of both the biotic community (living organisms) and the abiotic
environment. The latter has close interaction essential for
maintenance of life processes. The interaction is conducted by
energy flow (solar energy) in the system and cycling of materials
(natural cycles).
energy flow (solar energy) in the system and cycling of materials
(natural cycles).
From the biological point of view, the ecosystem has the
following constituents:
(i) Inorganic substances (carbon, nitrogen, carbon
dioxide, water, etc.) involved in natural cycles.
(ii) Organic compounds (proteins, carbohydrates, humic
substances) etc.
(iii) Air, water and substrate environment including the
climatic regime and other physical factors.
(iv) Producers, autotrophic (i.e., self-sustaining organisms)
green plants that can manufacture food from simple
inorganic substances.
(v) Heterotrophic (i.e., that depend on others for
nourishment) organisms, mainly bacteria, fungi and
animals which live on other organisms or particulate
organic matter.
(vi) Micro-consumers, decomposers, mainly bacteria, fungi
which obtain their energy by breaking down dead tissues
or by absorbing dissolved organic matter, extracted from
plants or other organisms.
The decomposers release
organisms.
Bacteria, fungi (and animals) often excrete hormone-like substances that inhibit or stimulate other biotic components of the ecosystem.
