Terrestrial ecosystems

Lesson 13: Types of ecosystems

Terrestrial ecosystems

Forest ecosystem: Forests occupy 40% of the land. In India it is 1/10th of the total land area. Forests are formed by a community of plants, i.e. tress, shrubs, climbers and ground cover. There is a gradual decrease in biomass of organisms at successive levels from producers to the carnivores. Thus, pyramid is upright. Forest ecosystem is formed by abiotic and biotic components.

  1. Abiotic components: These are the inorganic as well as organic substances present in the soil and atmosphere. Light conditions are different due to complex stratification in the plant communities. Forest type depends upon the abiotic factors such as climate and soil conditions of a region.

  2. Biotic component: The living organisms present in the food chain occur in the following order.
    1. Producers: These are mainly trees with species diversity depending upon the kind of forest formation developing in that climate. Besides trees, there are also several climbers, shrubs and a ground vegetation.

    2. Consumers :
      Primary consumers:
      These are the herbivores that include the animals feeding on tree leaves as ants, flies, beetles, leafhoppers, bugs and spiders etc. and larger animals grazing in shoots and or fruits of the producers, the elephants, deer, squirrels, flying foxes, fruit bats etc.
      Secondary consumers: These are the top carnivores like snakes, birds, lizards, fox etc. feeding on the herbivores.
    3. Tertiary consumers: These are the top carnivores like lion, tiger etc. that eat carnivores of secondary consumers level.

    4. Decomposers: These are wide variety of microorganism including fungi, bacteria and actinomycetes. They actively participate in biogeochemical nutrient recycling .

Last modified: Saturday, 31 December 2011, 10:42 AM