Components of Ecosystem

An ecosystem is made up of two types of components. Non-living or abiotic and living or biotic.
Abiotic Components of Ecosystem
Abiotic components consists of non-living material and energy. These components include every thing that surrounds and individual organism except other living organism.
Abiotic components are basically of two types; Material and Energy. The material may be both organic and inorganic and include carbon, nitrogen, water mineral, carbohydrates, proteins etc. The energy is in the form of light, heat or chemical energy obtained by breakdown of chemical bonds.
The abiotic components are controlled by abiotic factors which can be divided into three categories
1. Climate Factors
2. Topographic Factors
3. Edaphic Factors
1. Climate Factors
Light
Light is the ultimate source of energy for an ecosystem and plays an important role in the lives of both plants and animals. Plants use light for photosynthesis. In terrestrial ecosystems, light is not a limiting factor because only about 3% of available light is used for photosynthesis. However, in deep and turbid waters, light can be a limiting factor for photosynthesis. Light affects organisms in three ways; Intensity of light, its duration or photoperiod and its quality (wave length).
Intensity of Light
The intensity of light depends upon season, latitude, angle of incidence and time of day. Plants are classified according to their requirement of light and shade into heliophytes and sciophytes. Intensity of light plays important role in plants. In plants intense light may destroy the chlorophyll. It also affects opening and closing of the stomata, permeability of the cell membrane, height and surface area of plant etc. In animals light affects development of pigments.
Photoperiod
Duration of light (photoperiod) affects flowering, leaf fall and other aspects of plant growth. In animals biological rhythms such as reproductive cycles sleep cycles, hibernation, migration, are affected by light duration.
Quality of Light
Out of seven colours of visible light (electromagnetic spectrum), chlorophyll absorbs only red and blue light for photosynthesis. Light of short wave length such as ultraviolet rays is harmful for life. Most of the light reaching the earth is converted to heat and thus light also affects the temperature of the ecosystem.
Temperature
Environmental temperature affects the structure and distribution of organisms because of its effects on biological processes. The living organism can function only between temperatures of 0⁰C and 50⁰C and beyond that range they die. Temperature of water usually does not show vast variations therefore aquatic life possess very few adaptions related to temperature. However, most land animals have adaptions to face sudden changes in temperature.
Water
Water is most important ecological factor because it is essential for life and directly effects the physiology distribution and structural adaptations of both animal and plants. It acts as a limiting factor in terrestrial ecosystems. The availability of water in an ecosystem depends on factors such as rain, snow, type of the soil, kind of vegetation etc. Water is the raw material for photosynthesis and also plays part in many vital biochemical reactions, It determines the quality and quantity of flora and fauna of an ecosystem. In areas where there is more rain forest are formed and where less water is available deserts are found. Therefore, both plants and animals show many adaptations with regard to water. The water is continuously recycled in nature in the form of hydrological cycle.
Atmosphere and Wind
Atmosphere is a gaseous cover around the earth. The main gaseous component of the atmosphere are CO₂, oxygen, nitrogen and water vapour. The CO₂ is essential for photosynthesis; oxygen is essential for respiration; while nitrogen is necessary for protein synthesis. Therefore, most of the components of atmosphere are linked with bio-geo-chemical cycles.
Wind is the circulation an the moving atmosphere. The velocity of the wind can affect the growth and distribution of vegetation, particularly trees. Plants in exposed areas with high winds show adaptations like presence of strong stem and roots. The dispersal of seeds and spores in plants and migration of birds is affected by the winds. Strong winds increase the rate of transpiration and can create xerophyic conditions.
Fire
Natural fires are mainly caused by lightning, volcanic activity, mutual friction between tree branches etc. It brings about sudden changes in an ecosystem by destroying many species of plants and animals. Fire also have some positive effects. For example they release and recycle many nutrients. In many areas of the world forests have been changed to grass lands due to effect frequent fires. Fire also favours growth of some fungi. These fungi are called pyrophilus fungi.
2. Edaphic Factors
The factors relating to condition and composition of soil are known as edaphic factors. The scientific study of soil is called pedology. The soil is a layer of materials lying above the rocks of earth’s crust. It forms a link between the non-living and living components. The type of soil determines the kind of plants which can grow well in a particular ecosystem. The structural components of the soil are inorganic material, organic material and soil water. Formation of soil depends upon two processes
a. Weathering: It is the breakdown of rocks into fine particles of minerals.
3. Topographic Factors
Topography refers to the physical features of land of an area and includes such components as shape of the surface, altitude, slope exposure to wind etc. Topographic can influence many climatic factors and thus plays an important role in ecosystem.
i. Altitude
Higher altitude generally have lower temperature higher rainfall, increased wind speed, more light or exposure to sun etc. Therefore vegetation at different altitude is different and show distinct zonation.
ii. Slope
Steep slope have fast drainage and therefore the soil becomes thinner and cannot retain water. Consequently, mountains usually show xerophylic vegetation. In northern hemisphere, south facing slopes get more sunlight than north facing slopes and therefore, there is marked difference in the vegetation.
iii. Direction of Mountains
Mountains and their direction affect the climate by changing the direction of the rain laden wind. The windward side of mountain have more rainfall than the other side.