TYPES OF ECOSYSTEMS• Earth is a giant ecosystem where different biotic and abiotic components are constantly interacting with each other.• TYPES : (a) Terrestrial – forest, grassland, deserts. (b) Man made – croplands. (c) Aquatic - fresh water, marine, estuarines.
FOREST ECOSYSTEM• Depends upon various factors such as annual rainfall, its distribution in different areas, mean temperature, relative humidity, total annual wet and dry period.• COMPONENTS : ABIOTIC – Inorganic, Organic litter, minerals. BIOTIC - Producers, primary consumers, secondary consumers, tertiary consumers and Decomposers.
PRODUCERS – Vegetation of the forest is the ra producer. All contains chlorophyll pigment and perform the process of photosynthesis. -Abiotic components are synthesized in the form of carbohydrates (food).PRIMARY CONSUMERS – Herbivores, insects, pests, birds, flies, spiders etc.SECONDARY CONSUMERS – Carnivorous animals like snakes, birds, fox, jackal etc.TERTIARY CONSUMERS – Top carnivores like lions, tigers, hawks etc.DECOMPOSERS – Microorganisms that recycles the nutrients.
GRASSLAND ECOSYSTEMS• Grasslands cover about 19% of the earth’s total surface.• ABIOTIC COMPONENTS – Nutrients such as C, N, H, O, P, S, etc. supplied by air and soil.• BIOTIC COMPONENTS – PRODUCERS- Herbs and shrubs. PRIMARY CONSUMER – Cattle, Rodents, Insects and all animals feeding on grass.
• SECONDARY CONSUMERS – Foxes, jackals, snakes, frogs, lizards, wild dogs etc.• TERTIARY CONSUMERS – Birds such as Hawks etc.• DECOMPOSERS – recharges the mineral contents of the soil and make it useful for farming.
DESERT ECOSYSTEMS• Deserts constitute about 17% of land, occurring in regions where annual rainfall is less than 25 cms.• Species composition is quite specific due to extreme climatic conditions.• BIOTIC COMPONENTS : PRODUCERS : Shrubs, some grasses, that have branched root system with stems and branches variously modified to reduce water loss. Eg. Cactus (Xerophytes)
• CONSUMERS : The most common are reptiles and insects able to live under xeric conditions. Some nocturnal rodents and birds. Camels “The ship of the desert “ feed on tender shoots of these plants.• DECOMPOSERS : Due to poor vegetation, the amount of organic matter available is less. Very few Thermophillic bacteria and fungi survive in such conditions.
CROPLAND ECOSYSTEMS• Artificial system aimed at growing a single species of own choice. Wheat, maize, rice, bajra, jowar, sugarcane, veget ables etc.• A no. of weeds also contribute like cynodon dactylon, euphorbia hirta, launaea nudicaulis etc.• COMPONENTS : ABIOTIC – Inorganic, Organic litter, minerals. BIOTIC - Producers, primary consumers, secondary consumers, tertiary consumers and Decomposers.
ZONES OF A LAKE• Littoral zone-The zone close to shore• Limnetic zone - This is the layer of open water where photosynthesis can occur.• Profundal zone - Many lakes (but few ponds) are so deep that not enough light reaches here to support net primary productivity.
MARINE ECOSYSTEMS• Marine ecosystems are among the largest of Earths ecosystem. They include oceans, salt marsh and estuaries, mangroves, the deep sea and the sea floor, which have a higher salt content.• Marine waters cover two-thirds of the surface of the Earth. Such places are considered ecosystems because the plant life supports the animal life and vice-versa.
ESTUARINE ECOSYSTEM• Estuaries form a transition zone between river oceans and are subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of fresh water and sediment.• The inflow of both seawater and freshwater provide high levels of nutrients and sediment, making estuaries among the most productive natural habitats in the world.• Act as breeding areas for deep water fishes.