ABIOTIC FACTORS OF ENVIRONMENT

1. Temperature

  • It is the most important factor plays a significant role in determining the habitat. A few organisms, that can tolerate a wide range of temperature, are called Eurythermal, and the majority of the organisms that tolerate a narrow range of temperature, are known as Stenothermal.
  • The temperature ranges from 0o C in polar region to >50o C in tropical regions. Even in the same habitat the temperature may vary from one season to another. There are some unique habitats, such as hot springs and hydrothermal vents, where the average temperature exceed 1000 C.
  • You are aware about the habitats of mango tree, polar bear, snow leopard and tuna fish etc. The mango trees of tropical and sub tropical region can not grow in temperature countries like Germany and Canada. The polar bear and Snow leopard can not be found in the forests of Tamil Nadu. Kerala etc. and similarly the tuna fish is not found in the oceans of temperature region.
  • The problem of global warming in recent years is affecting the distribution range of various species.

2. Light

  • Most of the plants (Autotrophs) require sun light for the synthesis of food (photosynthesis). Some plant like shrubs and herbs photosynthesise in low light conditions. The marine plans (algae), inhabiting different depth of ocean, need different colour components of visible spectrum. The red algae (with red pigment phycoerythrin), as compared to brown or green algae, is found in greater depth of sea and absorbs blue light for photosynthesis
  • The sun light can not penetrate deep into the ocean. At the depth of >500 m the inhabitants live in dark and can not photosynthesize for energy production. The source of energy in such deep sea organisms (like bacteria) is Chemosynthesis. The animals of deep sea areas are either blind or show bioluminescence.
  • The animals also require light for their diurnal and seasonal activities. The foraging migration and reproduction depend on specific photoperiods (duration or exposure) and intensity of light. The sun light is also the source of heat and varies from one biome to the other.

3. Water

The water is another important abiotic factor that influences the life of the organisms. As you know that life on earth has originated in water and without water life cannot be sustained. The availability of water, in the form of precipitation, is different in different biomes. In desert, the plants and animals have special adaptations for the scarcity of water. In aquatic organisms the pH and chemical composition of water are important for their survival. The salinity (the salt concentration in ppm, i.e., parts per million) is<5% in inland water, 32-35% in sea and>100% in some hyper saline lagoons. Most of the fresh water animals can not live in sea water for a long due to osmotic problems. The same happens when a marine animal is transferred to a fresh water body.

4. Soil

The study of soil, an Edaphic factor, is called Pedology. The soil is weathered superficial layer of earth’s crust which is intermixed with the living organisms. The nature or properties of the soil varies from place to place, depending upon climate, weathering and the process of soil development. The plant depend upon soil for nutrients, water supply and anchorage. The holding capacity, pH, percolation properties, topography and mineral composition determine the types of vegetation in the area. A good fertile soil consist of mineral matter \left( { \sim 40\% } \right), water/soil-solution \left( { \sim 25\% } \right), soil air \left( { \sim 25\% } \right) and organic matter \left( { \sim 10\% } \right). The ‘loam’ is best for the plant growth. The soil also affect seeds-germination, size of plants, depth of the roots system,susceptibility to frost and parasites, and the flowering in the plants. The type of vegetation also determines the type of animals which it supports.

In case of aquatic environment, it is the type of sediments that determines the category of the thriving organism.

Post Author: E-Biology

Leave a Reply

Your email address will not be published. Required fields are marked *