Grass land ecosystem

Presentation by

Jhansirani.R AP/ECE

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

Types of grasslands

• Based on different climatic regions grasslands are of types

Tropical grasslands Temperate grasslands Polar grasslands (arctic tundra)

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

Savanna

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.

Termite mound

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.

Trees of savanna

Baobab

Acacia

 Candelabra 

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

Temperate grassland

Prairie in Effigy Mounds National Monument, Iowa, United States

Pampas, Argentina

Velds, Africa

Steppes, Mongolia

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.

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.

Polar grassland

Desert ecosystem

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.

Types of deserts

• Based on different climatic conditions deserts are of 3 major types

Tropical deserts Temperate deserts Cold deserts

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.

Tropical desert (Thar) , India

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.

Temperate desert (Gobi) in Inner Mongolia

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.

Rank Desert’s Name Type of desert Location

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

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

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.

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.

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.

Roadrunner

Anteater

ScorpionGila monster (lizard)

Camel