What are the two main components of an ecosystem? Describe the physical factors which affect the distribution of organisms in different habitats.
Abiotic (physical) and biotic components are the two main components of an ecosystem. Abiotic components or physical factors: 1. Temperature: The physiological and behavioral adaptations of most animals depend upon the changes in the environmental temperature. The rates of photosynthesis and respiration in plants also fluctuate depending upon the change in temperature. 2. Water: The extent to which an organism is dependent on an abundant water supply depends on its requirements and its ability to conserve it in adverse conditions. Organisms living in dry habitats generally have good water conservation such as in cacti and camels. Light: This is essential for all green plants and photosynthetic bacteria, and for all the animals dependent on the plants. 4. Humidity: This is important because it can affect the rate at which water evaporates from the surface of an organism, which in turn influences its ability to withstand drought. 5. Wind and air currents: This particularly applies to plants. Only plants with strong root systems and tough stems can live in exposed places where winds are fierce. The wind is also instrumental in the dispersal of spores and seeds. 6. pH: This influences the distribution of plants in soil and fresh-water ponds. Some plants thrive in acidic conditions others in neutral or alkaline conditions. Most are highly sensitive to changes in pH. 7. Soil nutrients: These particularly affect the distribution of plants in the soil. 8. Water currents: Particularly in rivers and streams. Only organisms capable of swimming or avoiding strong currents can survive. 9. Topography. Minor topographical differences may be just as important in influencing the distribution of organisms as wide geographical separation. Background. The distribution of organisms whose shape or coloration is such that they are camouflaged when viewed against a particular background is related to the general texture and pattern of the environment
