Monday, September 15, 2014

Structure and Function of an Ecosystem

Structure and function of an ecosystem
The two important aspects of an ecosystem are:
  • Structure and
  • Function

Structure of an ecosystem consists of
  • Composition of biological community (eg: plants, animals and microbes), biomass, life cycles and distribution in space.
  • Quantity, distribution and cycling of non-living materials (macro and micro nutrients, trace elements and water)
  • Variation of conditions like temperature, rainfall, sunlight, relative humidity, wind and topography.
Function of an ecosystem consists of
  • Rate of biological energy flow (production and respiration rates)
  • Rate of nutrient cycles
  • Ecological regulation (Environment regulation in the form of photoperiodism and Organism regulation in the form of nitrogen fixation by organisms)

From the trophic stand-point, an ecosystem has two components
  • Autotrophic component and
  • Heterotrophic component

Autotrophic component involves
  • Fixation of light energy
  • Use of simple inorganic substances like carbon and water
  • Synthesis of hexose sugars (glucose) to complex substances such as polysaccharide carbohydrate (starch), fat and protein synthesis.

Heterotrophic component involves
  • Utilization
  • Rearrangement and Decomposition of complex substances
  • Herbivores, Carnivores and Omnivores (Phagotrophs) and microconsumers (decomposers, osmotrophs and saprotrophs) comprise the heterotrophic component.