Desert Ecosystem-1.pptx adaptations of animals who survive in desert area
- 3. DESERT Desert is dry arid land with warm temperature and very little vegetation. Desert is also called as sand seas or oceans of sands. Desert ecology is the study of interaction between both biotic and abiotic components of desert environment. Desert are found on every continent with the largest being located on Antarctica (5.5million sq. Miles), the artic, northern Africa and middle East. Desert areas cover nearly one third of the land surface of the globe.
- 4. CHARACTERISTICS OF DESERT • Sandy soils and Rocky substratum like mountains, gravels etc. • Scanty rainfall below 250 mm per year. • Hot and cold weather. • Sand dunes-large piles of wind borne sands reaching a maximum height of 250M above the surface. • Temperature variation:- In summer temperature reaches up-to 38degree C during day and drops up-to 25degree C at night. During winter temperature in desert ranges from 10 degree to 21 degree C. • Oasis- it is wet and fertile zone in a desert with vegetation. Underground water comes nearer to the ground surface. Fauna and flora- with adaptions to survive in harsh environment.
- 5. TYPES OF DESERT Sahara desert in Africa Hot and dry desert In hot and dry deserts, also known as arid deserts, the temperatures are warm and dry year-round. Some famous arid deserts include the Sahara Desert that covers much of the African continent and the Mojave Desert located in the southwest of the United States.
- 6. COASTAL DESERT Coastal deserts occur in cool to warm areas along the coast. They have cool winters and long, warm summers. Coastal deserts are located on the west coasts of continents between 20° to 30° latitude. Ex- Atacama desert of Chile in South America.
- 7. COLD AND POLAR DESERT Desert lands with extremely low temperatures are called cold deserts like Antarctica, which is the largest cold desert in the world. Ladakh in India is a cold desert that lies in the Great Himalayas on the eastern side of Jammu and Kashmir. Ex- Antarctic desert, Ladakh, Himalayas.
- 8. RAIN SHADOW DESERT A rain shadow is a patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather. On one side of the mountain, wet weather systems drop rain and snow. On the other side of the mountain the rain shadow side all that precipitation is blocked. Ex:- Atacama desert in Chile and Gobi desert in Mongolia.
- 9. REASONS FOR FORMATION OF DESERT 1) Natural situation. 2) Air circulation pattern. 3) Remote situation from oceanic moisture. 4) Mountain barrier. 5) Less rain. 6) Temperature 7) Human activities.
- 11. BIOTIC FACTORS CREOSOTE BUSH Animal scatters mesquite seeds They lie in wait for rains sometimes for decades. Face a race against the clock Must quickly send down deep roots before the water dries up.
- 12. MESQUITE Digging deep for water The Sonoran Desert is located in Arizona, Calif., and northern Mexico. Mesquite seedling emerges from a cow pie. When animals eat mesquite seeds, they help spread seeds across the desert in their dung. A trip through an animal’s gut also helps break down the seed’s hard coating, preparing it to sprout. VELVET MESQUITE (Prosopis velutina)
- 13. PLANT FRIENDLY BACTERIA Plants alert their tissues by producing ethylene (ETH-uh-leen) gas. Plants make this hormone in a strange way. First, a plant’s roots make a chemical called ACC (short for 1-aminocyclopropane-l- carboxylic acid). From the roots, ACC travels up a plant, where it will be converted into ethylene gas. But bacteria can interrupt that process by consuming the ACC. When that happens, the plant never gets its own message to stop growing. PLANT FRIENDLY BACTERIA
- 14. CAT’S CLAW ACACIA The thorns of a cat’s claw acacia look just like little cat’s claws. This plant is well adapted to life in the desert. CAT’S CLAW ACACIA
- 15. THE WILDFLOWER ‘HEDGE’ Jennifer Gremer harvests annual plants to take back to the lab. “I had been monitoring these plants through the season to see how fast they were growing, whether they survived, when they started flowering, and how many flowers they produced,” she explains.
- 16. Ursula Basinger, of the University of Arizona, uses a transparent sheet, placed on a Plexiglas “table,” to map individual annual plants at a site. Scientists update the map after each rainfall in fall and winter and note every seed that germinates. Repeated checks show which survived and how many seeds each plant later produced.
- 17. Camels are able to withstand ambient temperatures of 44℃ without sweating. Cold-blooded animals entirely lack sweat glands as they rely on the external environment to regulate body temperature. Conservation of water through reduced sweating.
- 18. The average daytime temperatures in the desert often exceed more than 38°C. Nocturnal lifestyle helps to cut down the loss of water, especially in desert biomes. It also enhances osmoregulation. Some animals become active during twilight hours, i.e., during dawn and dusk. Such animals are called crepuscular animals. ADAPTION TO NOCTURNAL LIFE
- 19. Birds and reptiles in the desert retain water as their metabolic wastes are excreted in the form of an insoluble white compound called uric acid. When compared to mammals, the metabolic wastes are excreted through urea, a considerably more soluble compound. SPECIALIZED MODE OF EXCRETION
- 20. OTHER SOURCES OF WATER Natural sources of water, such as lakes and river are almost non-existent or are seasonal. So, animals derive water from desert plants such as cactus. Some insects also tap fluids such as saps and nectars from various parts of the plants.
- 21. SPECIALIZED APPENDAGES Animals like the jackrabbit have very large ears that have a network of blood vessels. When these animals rest in the shade, their enormous ears dissipate the excess heat from their bodies.
- 22. FOOD CHAIN
- 23. FOOD WEB
- 25. 2. OFF READING.
- 28. 5.GLOBAL WARMING
- 29. 6.DUMP SITES.
- 30. THANK YOU