2. Grass land ecosystem
• Grass lands are dominant by grass
species
• Sometimes allows the growth of few trees
and shrubs
• Rainfall is average but erratic (25-75)cm
• Limited grazing helps to improve primary
production off grassland
• Overgrazing leads to degradation resulting
in desertification
3.
4. Types of grasslands
• Based on different climatic regions
grasslands are of types
Tropical grasslands
Temperate grasslands
Polar grasslands (arctic tundra)
5. Tropical grasslands
• They are near the borders of tropical rain
forest
• Found in region of high average
temperature
• Rain fall is low to moderate
• In Africa they are known as Savannas
• They have tall grasses with scattered
shrubs and stunted trees
7. Savanna
• Savanna have wide diversity of animals
• Zebras, Giraffes, Gazelle, Antelopes etc.,
• During dry season fires are quite common
• Termite mounds are very common here.
• Termites gather the detritus containing a lot
of cellulose and build up a mound
• On Top of the mound fungi are found to grow
which feed upon this dead matter including
cellulose and in turn release methane, a
greenhouse gas.
9. Tropical savanna
• Tropical savanna have a highly efficient
system of photosynthesis.
• Most of the carbon assimilated by them in
the form of carbohydrates is in the
perennating bulbs, rhizomes, runners etc.,
which are present underground
• Burning of these grasslands can release
huge quantity of CO2, a green house gas,
responsible for global warming.
11. Temperate grassland
• They are found on flat, gentle sloped hills
• Winters are very cold
• Summers are hot and dry
• Intense grazing and summer fires do not
allow shrubs are trees to grow
• In U.S & Canada – Prairies
• In south America – Pampas
• In Africa – Velds
• In Central Europe & Asia - Steppes
17. Temperate grassland
• Winds keep blowing
• Evaporation rate is very high
• Favors rapid fires in summer
• Soil is quite fertile and therefore, often
these grasslands are cleared for
agriculture.
• Animals like Deer, Bison, Saiga, Wild
horses, Coyotes, ect., are found here.
18. Polar grassland (arctic Tundra)
• They are found in arctic polar region
• Severe cold & strong, frigid winds along with ice and
snow create too harsh a climate for trees to grow
• In summer sunshine's hence several small annual
plants grow in summer
• Animals include arctic wolf, weasel, arctic fox, reindeer
• A thick layer of ice remains frozen under the soil
surface throughout the year is known as permafrost.
• In summer it appears like shallow lakes, bogs etc.,
• Where mosquitoes, insects and migratory birds
appear.
21. Desert ecosystem
• They occur in regions where evaporation
exceeds precipitation
• Rainfall is less than 25cm/year
• About 1/3rd
of our worlds land area is covered by
deserts
• Deserts have little species diversity
• It consist of drought resistance or drought
avoiding plants
• Atmosphere is very dry, hence a poor insulator
• That’s why in deserts soil gets cooled up quickly
making the nights cool.
22. Types of deserts
• Based on different climatic conditions
deserts are of 3 major types
Tropical deserts
Temperate deserts
Cold deserts
23.
24.
25. Tropical deserts
• Sahara and Namibia in Africa
• Thar desert, Rajasthan, India
• These are the driest of all with only few
species
• Wind blown sand dunes are very common
• Camel, Armadillo, Bandicoot, Bat, Black widow
spider, Desert Tortoise, spiny-tailed lizard,
scorpions, snakes are found here
• Plants like Cactus, Joshua tree, Palm tree grow
here.
27. Temperate deserts
• Monjave in south California
• Day time temperature is very hot in
summer but cool in winter
• Has a variety of different animals
including
different types of mammals, birds and
reptiles.
29. Cold deserts
• Gobi desert in china has cold winters and
warm summers
• The main plants are deciduous, most having
spiny leaves.
• Widely distributed animals are jack rabbits,
kangaroo rats, kangaroo mice, pocket mice,
grasshopper mice, and antelope ground
squirrels.
30. 1 Antarctic Desert Polar Antarctica
2 Sahara Subtropical Africa
3 Arctic Polar Alaska , Canada, Greenland (Denmark), Iceland and Russia
4 Arabian Desert Subtropical Saudi Arabia, Jordan, Iraq, Kuwait, Qatar, UAE, Oman, Yemen
5 Gobi Desert Cold Winter Mongolia and China
6 Kalahari Desert Subtropical Angola, Botswana, Namibia and South Africa
7 Patagonian Desert Cold Winter Argentina and Chile
8 Great Victoria Desert Subtropical Australia
9 Syrian Desert Subtropical Syria, Jordan and Iraq
10 Great Basin Desert Cold Winter United States
11 Chihuahuan Desert Subtropical Mexico and United States
12 Great Sandy Desert Subtropical Australia
13 Karakum Desert Cold Winter Turkmenistan
14 Colorado Plateau Cold Winter United States
15 Sonoran Desert Subtropical Mexico and United States
16 Kyzyl Kum Cold Winter Kazakhstan, Turkmenistan and Uzbekistan
17 Taklamakan Desert Cold Winter China
18 Thar Desert Subtropical India and Pakistan
19 Gibson Desert Subtropical Australia
20 Simpson Desert Subtropical Australia
21 Atacama Desert Cool Coastal Chile and Peru
22 Namib Desert Cool Coastal Angola and Namibia
23 Dasht-e Kavir Cold Winter Iran
24 Mojave Desert Subtropical United States
25 Dasht-e Lut Cold Winter Iran
31. Desert plants
• Desert plants and animals has most typical
adaptations for conservation of water
• Many desert plants have reduced scaly
leaves to cut down loss of water due to
transpiration
• They may have succulent leaves to store
water
• Their stems get flattened and develop
chlorophyll for photosynthesis
32. Desert plants
• Some have deep roots to tap ground
water
• Many plants have waxy, thick cuticle over
the leaf to reduce loss of water
• Due to low species diversity, shortage of
water and slow growth rate, desert plants
if face with sever stress takes long time to
recover.
33. Desert Plants
• Many plants are found in the desert.
They usually grow close to the ground.
• Thick stem, shallow and wide roots, and
thick skin covered with spines instead of
leaves.
34. Desert Animals
• There are many animals in the desert.
• They can survive by eating other animals or by eating
plants that store water.
• To protect them from the hot sun, they stay in the
shade or in their shelter.
• They usually live inside burrows where humidity is
better and heat is less.
• Animals may build their shelters inside plants.
• Some animals sleep during the day and are active at
night.
• Some animals have hard shells to protect them from
losing much water.
• Desert soil is rich in nutrients but deficient in water.