Definition, concept, structure and functions Ecology is the science that deals
with the relationships between living organisms with their physical environment and with
each other. Ecology can be approached from the viewpoints of (1) the environment and the
demands it places on the organisms in it or (2) organisms and how they adapt to their
environmental conditions. An ecosystem consists of an assembly of mutually interacting
organisms and their environment in which materials are interchanged in a largely cyclical
manner. An ecosystem has physical, chemical, and biological components along with energy
sources and pathways of energy and materials interchange. The environment in which a
particular organism lives is called its habitat. The role of an organism in a habitat is called its
niche. For the study of ecology it is often convenient to divide the environment into four
broad categories. In practice, the two approaches are usually merged. Descriptive ecology
describes the types and nature of organisms and their environment, emphasizing structures of
ecosystems and communities and dispersions and structures of populations. Functional ecology
explains how things work in an ecosystem, including how populations respond to environmental
alteration and how matter and energy move through ecosystemsNatural ecosystems are those that
are existing in nature; they are further classified into terrestrial and aquatic. Terrestrial includes hot
desert, grass land, tropical and temperate rainforest and aquatic includes ponds, river, streams,
lakes, estuaries, oceans, mangroves, swamps and bays etc. However these two ecosystems are self
regulating, open system with a free exchange of inputs and outputs with other systems. Artificial
ecosystems are simple, human-made, unstable and subjected to human intervention and
manipulation. Usually it is formed by clearing a part of the forest or grassland e.g. crop field,
agricultural landStructure and Function of an ecosystem An ecosystem has two components the
biotic components consisting of living things thingsand the abiotic portion, consisting of elements
that are not alive. The non living constituents are said to include the following category, habitat,
gases, solar radiation, temperature, moisture and inorganic and organic nutrients. The living
organisms may be sub divided into producers, consumers and decomposers. Abiotic Components
include basic inorganic and organic components of the environment or habitat of the organism. The
inorganic components of an ecosystem are carbon dioxide, water nitrogen, calcium phosphate all of
which are involved in matter cycle (biogeochemical cycles). The organic components of an
ecosystem are proteins, carbohydrates, lipids and amino acids, all of which are synthesized by the
biota (flora and fauna) of an ecosystem and are reached to ecosystem as their wastes, dead remains
Control of pests and pathogens in industrial agriculture relies heavily on the use of chemical
pesticides. Pesticide use has however created almost as many problems as it was designed to solve.
Industrial agriculture displays many of the characteristics of manufacturing industry such as high
capital expenditure on buildings and machinery; specialization of production; and large outputs of
wastes which are not recycled within the system. Wastes from industrial agriculture, such as
chemicals leached in drainage, are significant pollutants of other ecosystems. The most harmful
effects of industrial agriculture on the environment are however due to soil tillage and undue
exposure of bare soil, resulting in accelerated soil erosion and consequent depletion of the soil resource base.
Papet
ReplyDelete