The document discusses several types of natural ecosystems. It describes tropical rainforests as having the greatest diversity of plant and animal life, with tall trees competing for sunlight in the dense vegetation. Temperate forests typically contain deciduous and coniferous trees. Taiga ecosystems, also called boreal forests, are located in northern regions and consist mainly of pine and spruce trees. Grasslands contain wide open expanses often inhabited by grazing animals, and include savannas, prairies, and steppes. Desert ecosystems are characterized by sparse vegetation and limited animal life. Tundra ecosystems are frozen for most of the year but support lichens and small flowers in the brief summer. Coral reefs support a quarter

2. Natural Ecosystem
A Lecture
By
Allah Dad Khan

3. Natural Ecosystem
• An ecosystem is comprised of all the non-
living elements and living species in a
specific local environment. Components of
most ecosystems include water, air, sunlight,
soil, plants, microorganisms, insects and
animals. Ecosystems may be terrestrial – that
is, on land – or aquatic. Sizes of ecosystems
vary; they could entail a small puddle or an
enormous swath of desert. Likewise, natural
ecosystems can look quite different from one
another.

4. • TROPICAL RAINFOREST ECOSYSTEMS
• Located in tropical regions, rainforests possess
a greater diversity of plant and animal life
than any other type of ecosystem. As their
name implies, precipitation is significant,
leading to dense, verdant vegetation. Trees
grow very tall as they compete for sunlight,
and animals live in their canopy.

5. • TEMPERATE FOREST ECOSYSTEMS
• Forest ecosystems are common across
temperate climates – areas where winters are
cold and summers are warm. They usually
consist of deciduous trees, which shed their
leaves each autumn, and coniferous trees,
which stay green throughout the year.

6. • TAIGA ECOSYSTEMS
• Taigas are a type of forest ecosystem
located in the far northern regions of the
world. Also called boreal forests, they
consist mainly of evergreen, coniferous
trees, such as pine and spruce.

7. • GRASSLAND ECOSYSTEMS
• Grasslands, located in semi-arid zones, contain
wide, treeless expanses often inhabited by
grazing animals. Sub-categories of grassland
ecosystems include savannas, which are found
in the tropics; prairies, situated in temperate
regions; and steppes, which can be found in
either climate.

8. • DESERT ECOSYSTEMS
• With a drier climate than grasslands,
desert ecosystems are characterized by
relatively sparse vegetation, and the
number of insects and animals is also
relatively limited. Deserts aren’t
necessarily hot; they can lie in temperate
zones as well. Nor must they be sandy;
many deserts feature rock floors.

9. • TUNDRA ECOSYSTEMS
• Tundra ecosystems, located in polar
regions or on the tops of high mountains,
are frozen and snow-covered most of the
year. Life is hard in these white, treeless
swaths, but during the brief summer,
snows may melt enough to expose lichens
or small wildflowers and attract migrating
birds.

10. • STILLWATER ECOSYSTEMS
• Various aquatic ecosystems can be found in
stagnant or very slowly flowing waters.
Lakes, ponds, bogs, freshwater and saltwater
marshes, swamps and lagoons are examples
of ecosystems found in stationary or nearly-
stationary waters. Algae, plankton,
underwater and floating plants, such as lily
pads, may inhabit the calm waters.

11. • RIVER AND STREAM ECOSYSTEMS
• Consisting of flowing freshwater, river and
stream ecosystems support a variety of
underwater life. Their relatively fast-
moving waters boast a higher oxygen
content than that of stationary waters,
allowing greater biodiversity among plant
and animal species.

12. • LITTORAL ZONES
• Littoral zones are essentially coastlines,
the often shallow parts of the ocean
nearest the shore. The waters in littoral
zones experience a significant amount of
turbulence, due to wave action. Seaweed,
barnacles, mollusks and crabs may be
found in littoral zones

13. • CORAL REEFS
• Coral reefs are often referred to as the
“rainforests of the ocean” because these
ecosystems teem with life – an estimated
one-quarter of marine species rely on
them for food or shelter. In addition to
corals and brightly-colored fish, sponges,
sea anemones, sea urchins and clams
make their homes in coral reefs.