Environmental Factors

Environmental Factor

Environmental factor or ecological factor or ecofactor is any factor, abiotic or biotic, that influences living organism.  Abiotic factors include ambient temperature, amount of sunlight, and pH of the water soil in which an organism lives. Biotic factors would include the availability of food organisms and the presence of conspecifics, competitors, predators, and predatos.

1. Biotic Factor

Ecosystem is composed of biotic factors of a community of living organism interacting with one another which we can see in food chains/webs. These diverse organisms stay together because of the need of food. Population is referred to as a collection of same species. This population plays a role in maintaining the equilibrium in the ecosystem. Populations for food-- the roles played by the population in this feeding relationship are classified into the three major biotic components of an ecosystem namely:

• Producers

• Macro-consumer

• Decomposer

What are Producers?

These are organisms called producers can manufacture their own food from simple organic substances through the process of “photosynthesis”. They are often said to be “autotrophs” which comes from the Greek word “autos” which means self and “trophikos” which means nursing that refers to nutrition.

The name “autotrophic” pertains to “self-nourishment or self-feeding.” Producers manufacture foods by converting sunlight to energy in the process of photosynthesis. One good example is the chlorophyll-bearing plants and photosynthetic bacteria. But some producers manufacture food without the aid of sunlight by just using chemical energy of simple inorganic substances like mushrooms and the process is called “chemosynthesis” and the organism is known as chemosynthesis bacteria. Plants photosynthetic and chemosynthetic bacteria are autotrophic organisms that produce food in the ecosystem.

Producers are mainly of the first stage of food chain for they are the one of sustain and produce food for other living creatures or biotic factors.

Macroconsumers

This is mostly composed of herbivores, carnivores and omnivores. Macroconsumers are large consumers like animals depends food on other organism. Hence, macroconsumers like decomposers may also described as heterotrophic. The hetero which means other because the term describe organisms the feed on others, macroconsumers are grouped into three according to their food preferences;

1. Plants-eaters (herbivores) – These are consumers who eats plant leaves, flowers, stems, roots and etc. Some of the few examples of herbivores are carabao, horses and goats. Plant-eaters are vegetarian animals so meaning they do not eat meat of other animals.

1. Flesh-eater (carnivores) – These are animals that eat meat of other animals and some examples of carnivorous animals are dog, snake and hawk. They don’t eat plants but only eat meat of the animals. It comes from the Greek word “Carni” which means meat and the other means eaters.

1. Variety-eaters (Omnivores) –These are consumers who actually eat either plants or animal meats. Some examples of omnivorous animals are rat, chicken and man that eat both plants and animals.

Decomposers

Decomposers refer to small consumers like bacteria, fungi and worms that cause the decay of dead organism. They are sometimes called to as microconsumer because many of them are microorganisms that are too small to be seen by the naked eye.

They are also described as heterotrophic because the feed on other organism. Some decomposers like fungi are saphrotrophic. This means fungi take in food by absorbing dissolved organic substances that are products of decay.

Decomposers break down the complex substances in bodies of dead plants and animals into simpler materials. They are the final consumers of a biotic community. They return to the nonliving environment the materials which were originally absorbed by plants from the soil.

2. Abiotic Factors

Abiotic factors are the non-living components of a habitat. The abiotic factors in an ecosystem are grouped into soil (edaphic), air, topography, meteorology, availability of water and quality of water. The meteorological factors are temperature, wind, sun, humidity and precipitation. The activities and growth of plants and animals are a result of several of these abiotic factors. 

The abiotic factors play a major role in the environment.

The list of abiotic factors are

clouds, 

weather,

latitude,

temperature, 

oxygen, 

salinity, 

soil (edaphic factors), 

air, 

water, 

sunlight, 

humidity,

topography, 

pH, 

atmospheric gases

Soil - Edaphic Factors

The edaphic factors are the abiotic factors with respect to soil. These factors include 

• Soil texture -   The texture of the soil is variable from particles like clay to larger particles like sand. Sandy soils are suitablke for growing plants and are well aerated and are easy to cultivate. Sandy soils cannot retain much water and contain few nutrients required for plant growth. 

• Soil air - Soil air is the spaces between the soil particles where it is not filled with soil water. The soil air determines the firmness of the soil. 

• Temperature of soil - Temperature of the soil is an important factor, temperature of soil below 30cm is said to be constant but there are seasonal variations. The decaying caused by decay-causing microorganisms is low at lower temperature. 

• Soil water - Soil water is classified into three types - capillary water, hygroscopic water and gravitational water. 

• Soil pH - pH of the soil affects the biological activity in the soil and certain mineral availability. The pH influences the growth and development of plants.

• The organisms and the decaying matter in the soil is known as soil solution and it increases the fertility of the soil. 

Light

Light is the primary source of energy to almost all ecosystems. The light energy is used by the heterotrophs to manufacture food by the process of photosynthesis by combining together other inorganic substances. The factors of light like its quality, intensity and the length of the light period play a vital role in an ecosystem.

• The quality of light affects the aquatic ecosystems, the blue and red light is absorbed here and it does not penetrate deep into the water. Some algae have specialized pigments that absorbs the other colors of light. 

• The intensity of light depends upon the latitude and the season of the year. During the period from March to September the Southern Hemisphere receives less than 12 hours of sunlight while it receives more than 12 hours of sunlight during the rest of the year. 

• Some plants flower only during a certain time of the year. One of the factors is due to the length of dark period. Depending on the intensity of light the plants are classified as short-day plants (Example Chrysanthemum sp., Datura stramonium etc.) Long-day plants (Examples - Spinach, barley, wheat, radish, clover, etc.) Day-neutral plants (Examples - Tomato, maize, etc.) 

Temperature

Temperature influences the distribution of plants and animals. The occurrence of frost is an important to determine the distribution of plants as most of the plants cannot prevent freezing of their tissues. Below are a few examples of the effects of temperature in plants and animals: 

• The blooming of flowers either in the day or night is due to the temperature difference between day and night. 

• Some biennial plants germinate during spring or summer this is known as vernalization. 

• Some fruit trees require cold temperature so as to blossom in the spring. 

• Animals have a clear distinction between being cold blooded or warm blooded. 

• Seasonal migration is seen in some animals.  

Water

Habitats of animals and plants vary widely from aquatic environments to the dry deserts. Water is essential for life and all the biotic components of the ecosystem are directly dependent on water for survival. 

Based upon their water requirements plants are classified as: 

• Hydrophytes (Example - Water lilies)
• Mesophytes (Example - Sweet pea, roses)
• Xerophytes (Example - Cacti, succulent plants) 

Land animals are prone to desiccation and these animals show various types of adaptations to this. Some of the adaptations seen in terrestrial animals are:

• Body covering which limits loss of water. 

• Some animals have sweat glands which are used as cooling devices. 

• The tissues of some animals like camel are tolerant to water loss. 

• Some insects are said to absorb water from the water vapor directly from the atmosphere. 

Wind

Air currents or winds are a result of interaction between expansion of hot air and convection in the mid latitudes. This complex interaction influences the earth's rotation and results in a centrifugal force which lifts the air at the equator. Some of the effects of wind are: 

• Winds also carry water vapor; this may undergo condensation and fall in the form of rain, hail or snow. 

• It also helps in dispersal pollen grains of some plants and also in dispersal of insects. 

• Wind erosion also leads to dispersal of topsoil. 

Atmospheric Gases

Atmospheric gases like oxygen, nitrogen and carbon dioxide: 

• All organisms require oxygen for respiration. 

• Carbon dioxide is used by green plants to make food by the process of photosynthesis. 

• Nitrogen is necessary for all plants and atmospheric nitrogen is fixed by nitrogen fixing bacteria through the action of lightening. 

Topography
Topography is the landscape shapes which is determined by the aspects of slopes and elevations. Topography gives a variety to the ecosystems. For example: The grassland topography is varied like hills, prairies, cliffs, low lying areas etc, which gives variability to life forms. 

• The aspect of the direction of the land facing also varies as the land facing towards the south or the sun ar hotter and drier than areas in the north, which are away from the sun. 

• Slope of on areas is also important as water may run downhill and may soak in ground which makes it available for plants. The areas in the southern part with slopes will be much be hotter and drier than the northern areas with slopes. 

Climate
Climate of a region includes the average rainfall, temperature and the patterns of winds that occur. Climate is one of the most important abiotic factors of an ecosystem. 

• Temperature of an area and the precipitation factor determines whether the region is grassland or a forest. 

• The rainfall an area receives influences the productivity of the area and the types of plants.

• For example: The climate in a grassland ecosystem is dry and hot during the spring and summer and is cool and cold during the winter. 

• Precipitation in winter is snow rather than rainfall. During summers, more water is evaporated from the grasslands making the region deficient of moisture. 

 

References; Science and Technology by Lilia M. Rabago Ph. D , Crescensia C. Joaquin Ph.D, Catherine B. Lagunzad , PH. D, Encarta