1. 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.

2. 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.

3. 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.

4. 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.

5. • 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.

6. 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)

7. • 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.

8. 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.

9. FRESHWATER SYSTEMS

10. 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.

11. MARINE ECOSYSTEMS
• Marine ecosystems are among the largest of
Earth's 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.

13. 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.