ENVIRONMENTAL FACTOR
Hi guys.. long time no see. Well, today I will post and
share some knowledge about Ecology. From the tittle above, it will talk about
environmental factor. What is that? Environmental factor or ecological factor
or ecofactor is any factor, abiotic and biotic that influences living
organisms.
In any ecosystem, a living organism is influenced by a
number of factors and forces. These environmental factors are known as eco-factors or ecological factors which include light, temperature, soil, water
etc. These factors may be biotic (living) and abiotic (nonliving). The sum
total of all these factors constitutes the environment of an organism. Abiotic
factors refer to non-living physical and chemical elements in the ecosystem.
Abiotic resources are usually obtained from the lithosphere, atmosphere, and
hydrosphere. Examples of abiotic factors are water, air, soil, sunlight, and
minerals. Biotic factors are living or once-living organisms in the ecosystem.
These are obtained from the biosphere and are capable of reproduction. Examples
of biotic factors are animals, birds, plants, fungi, and other similar organisms. All these ecological factors can
be broadly classified into the following divisions:
A. Abiotic Factors
1. Climatic Factors
(a) Light
Light plays an
important role in the species composition and development of vegetation. Light
is abundantly received on the surface of the earth. And, on an average
approximately only 2-3 percent of this solar energy is used in Primary
Productivity. Light intensity shows special variations due to the factors like atmospheric
water layer, particles dispersed in the air, etc. Further, the vegetation of an
area may also affect the light intensity. In deep shade under trees, or under
water, light becomes limiting below which photo-synthesis is not sufficient for
effective growth.
(b) Temperature
Temperature is
a measurement of the degree of heat. Like light, heat is a form of energy. The
radiant energy received from the sum is converted into heat energy. Heat is
measured in calories. The temperature at which physiological processes are at
their maximum efficiency is called optimum temperature. The minimum, optimum
and maximum temperatures are called cardinal temperatures. The cardinal
temperature varies from species to species, and in the same individual from
part to part.
(c) Water
Water is an
indispensable part of land and soil productivity. The misuse of water leads to
soil degradation and erosion. Proper management of water is highly necessary
for better production. Water is also indispensable for human beings. Thus, it
goes without saying that water is the most important substance necessary for
life. All the physiological processes take place in the medium of water.
Protoplasm, the very basis of life, is made up mostly of water. Plants and
animals show considerable variation in their requirements of water.
(d) Rainfall
The main
source of soil water is precipitation. The rainfall provides water to plants
and animals. Rainfall occurs due to interchange of water between earth’s
surface and the atmosphere. This is known as the hydrologic cycle. In this
cycle two important things are precipitation and evapotranspiration.
(e) Wind
Air in motion
is called wind. It is a vital environmental factor. It affects plants, and
other organisms. It modifies the water relation and light conditions of a
particular region. Wind brings about a number of physical, anatomical and
physiological changes of plants. Such changes are breakage and uprooting of
plants, deformation, erosion and deposition, salt spray etc. The wind
accelerates transpiration, removes solid moisture and at high velocities causes
soil erosion.
(f) Humidity
Atmospheric
moisture in the form of invisible vapour is known as humidity. Humidity is
greatly influenced by intensity of solar radiation, temperature, altitude,
wind, water status of soil etc. Low temperature causes higher relative humidity
by decreasing the capacity of air for moisture. Processes as transpiration,
absorption of water etc. are influenced by atmospheric humidity. Humidity,
thus, plays an important part in the life of plants and animals.
(g) Atmospheric Gases
Some principal
gases like nitrogen, oxygen, carbondioxide, helium, hydrogen, methane, ozone
etc. are found in atmosphere. In addition to these gases, there are water
vapours. Industrial gases, dust, smoke particles, microorganisms etc. are
present in the atmosphere. These gases have important influence on the
environment.
2. Topographic Factors:
The factors
concerned with physical geography of the earth are known as topographic
factors. These factors influence vegetation which causes variation in climate
of a geographic region, ultimately give rise to a characteristic microclimate,
such as:
- Altitude of the place
- Steepness and Exposure of the slope
- Direction of mountain chains
3. Edaphic Factors
Edaphic
factors deals with different aspects of soil, such as the structure and
composition of soil, its physical and chemical features. Thus, soil has mainly
the following components:
- Mineral matter
- Soil organic matter or humus
- Soil water/soil solution
- Soil atmosphere
- Biological system (fauna of bacteria, fungi, algae, protozoa, ratifies, arthropods, etc.)
4. Limiting Factors
Limiting factors
is the environmental variables that can determine or negatively affect the
pupulation of different organism or species in an ecosystem. Limiting factors
also some aspect of the environmnet that limits an organism’s distribution. Limiting
factor consist of abiotic variable (temperature, salinity, water) and biotic
variable (competition, predation, disease).
B. Biotic Factors
Under natural
situations, organisms (such as: human, plant, animal, microorganism) live
together with their interactions directly and indirectly. The biotic factors
constitute the living organisms of the environment and definitely they have
their interactions. The population occurring together in an area interacts with
each other in several ways. In the study of environmental reactions of a
particular kind of organisms, these interactions are generally referred to as
the biotic factors. Biotic factors are useful in describing the number of
components in an environment of near or habitats known as forming the ecosystem
of its own, which on one hand is composed of parts of inorganic and on the
other hand the various organisms that live together as a unit sociology called
biota.
Source:
- Campbell, N.A. Jane B. Reece and Lawrence G. Mitchell. 2000.
Biologi Edisi Kedelapan Jilid 3. Jakarta: Erlangga
- http://www.environmentalpollution.in/
