Abiotic Factors

 (i) Temperature

• Most ecologically relevant environment factor.
• Seasonally, the average temperature on land varies.
• The temperature decreases propressively from the equator to the poles and from plains to the mountain top.
• The temperature can affect the kinetics of enzymes and through it the basal metabolism and other physiological functions of the organisms.
• The organism tolerating the high range of temperature is called eurythermal and the organism which can tolerate narrow range of temperature is called stenothermal.

(ii) Water

• It is the second important factor as life is unsustainable without water.
• The amount of water in an environment determines the productivity and distribution of plants.
• For aquatic habitat, the quality of water becomes important like pH value, salinity and temperature of water.
• The organisms tolerating wide range of salinities are called euryhaline and the organisms that tolerate only narrow range of salinities are called stenohaline.

(iii) Light

• Light is important because autotrophs make food with the help of light (photosynthesis) and O₂ is evolved during this process.
• The plants depend on sunlight to meet their photoperiodic requirement for flowering.
• For many animals, light is important in that they use the diurnal and seasonal variations.

(iv) Soil

• The nature and properties of soil depend on the climate and weathering process.
• The soil composition, grain size and aggregation determine the percolation and water holding capacity of the soil.
• The vegetation in an area is determined by some soil parameters like pH, mineral composition and topography.