Desert plants have developed various ways to get as much water as possible and to reduce water loss.Some plants have long roots to get water deep in the soil, or branched roots to get water over a wide area. With thick waxy layer on the stems and leaves, water can be retained and the tissues are protected from strong sunshine. Some plants have pin-like leaves to reduce water loss.        Barrel Cactus             Many desert plants are succulents and they store water in their swollen stems or leaves.  

World Rainforest Movement

Human impact in desert areas 1700,2000 and 2050

NTERDEPENDENCE - In all environments, various plants and animals depend on each other either directly or indirectly for survival.

These ecosystems are either barren or with scanty vegetation consisting of mainly thorny bushes. Deserts are classified as warm (hot) and cold (temperate) deserts. The hot deserts are the Sahara in Northern Africa, Kalahari in Southern Africa, Thar in India, Atacama in South America, deserts of Mexico and Australia.The deserts of Iran and Turkey, Gobi desert of Mongolia, some deserts of Argentina are recognised as temperate or cold deserts. Characteristics of Desertsi) Most deserts receive some rain every year but not uniform. ii) Light green covering of annuals is seen just after rains.iii) Have scanty vegetation, clear skies, hot days and extremely cold nights. iv) Soil is rocky and encrusted with sand or salt.v) Long periods without precipitation and extreme temperature (50 - 60oC) conditions (arid lands) impose considerable restraints on the flora and fauna which inhabit there. vi) Sandy storms are very frequent.vii) Occur generally in rain shadow areas. Flora1) Includes succulents such as Cacti and Euphorbias, which can store water in their tissues. 2) Trees with long spreading roots such as Acacia, Prosopis, Phoenix (dates) are found.3) Ephemerals (short lived) such as Boerhaavia repens are seen only during rainy season. FaunaMost desert animals are nocturnal and avoid the heat of the day by burrowing into the cooler soil. Animals include ants, locusts, lizards, Gila monster, coral snake, rattle snake, burrowing owls, Gambel's quail, kangaroo rats, rabbits, camel, skunk, badger foxes, jackals and desert cats. In general, the organisms having specialised structural and physiological and behavioural adaptations to withstand the extreme temperatures only can survive in a desert.

The 10 largest deserts Rank   Desert   Area (km²)   Area (mi²)   1 Antarctic Desert (Antarctica) 13,829,430 5,339,573 2 Arctic 13,700,000+ 5,300,000+ 3 Sahara (Africa) 9,100,000+ 3,320,000+ 4 Arabian Desert (Middle East) 2,330,000 900,000 5 Gobi Desert (Asia) 1,300,000 500,000 6 Kalahari Desert (Africa) 900,000 360,000 7 Patagonian Desert (South America) 670,000 260,000 8 Great Victoria Desert (Australia) 647,000 250,000 9 Syrian Desert (Middle East) 520,000 200,000 10 Great Basin Desert (North America) 492,000 190,000

The Amazon Rainforest By Alec The Amazon rainforest has many different plants that can be used as herbal medicines. Some of the most important medicines come from the Amazon. They have been used for hundreds and hundreds of years. These plants can be deadly if taken in large doses, but in small doses they can be very helpful. They can be used to cure headaches, skin irritation, high blood pressures, and many other diseases. Here are some of them. White Trillium The white trillium has three petals, three sepals, and three leaves. If the leaves are chewed, it can help cure snake bites. If the plant’s petals are chewed, they can help ease childbirth, and the sepals if chewed are used to help cure fevers. Cinchona Tree (Cinchona officinalis) The bark of this tree is used to make Quinine, a medicine that helps treat Malaria, a serious disease. A number of various other chemicals can also be made from Cinchona, and these chemicals include cinchonine, cinchonidine and quinidine. However, quinine has been replaced by other drugs such as chloroquine and mefloquine, and now quinine is rarely used to treat malaria. Foxglove (Digitalis purpurea) The leaves of this plant contain digitalis, a substance used to treat heart problems. When taken in large doses it can produce palpitations and dizziness, but when taken in smaller doses it can help the heart beat more slowly. This medicine had many effects, and sometimes it cured in miraculous ways, but it mostly produced violent reactions, occasionally killing because it was taken in very large doses. The foxglove tea is used as a morning tea to aid in birth control. Opium Poppy (Papaver somniferum) The opium poppy is used to make Morphine and Codeine, two drugs that are used as painkillers. The opium gum may be crudely refined and smoked, or converted to morphine and heroin.

The World's Lungs? In the past, scientists often referred to tropical rainforests as the "lungs of the world" because of the large amount of oxygen they produce. More recent evidence shows that rainforests don't have much of an effect on the world's oxygen supply. The decomposition of dead plant matter consumes roughly the same amount of oxygen that the living plants produce. But rainforests do play a key role in the global ecosystem. Some experts are now calling them the "air conditioners to the world," because their dark depths absorb heat from the sun. Without the forest cover, these regions would reflect more heat into the atmosphere, warming the rest of the world. Losing the rainforests may also have a profound effect on global wind and rainfall patterns, potentially causing droughts throughout the United States and other areas

Author: barry a bieda How does the cutting of the rainforest affect Earth? Response #: 1 of 1 Author: mortis Well, we have been cutting rainforests for thousands of years with no permanent damage to the earth at all. Forest people who cut small patches for growing gardens do not hurt the forest because the small plots recover their original growth very quickly: think of the pictures of Mayan ruins in Mexico that are completely covered by forest - these used to be open, active cities! So on a small scale, slash and burn agriculture has no effect whatever on the rain-forest- it is a sustainable use of the forest. However, on a large commercial scale, where bulldozers and flame-throwers are use to convert huge tracts of land into pasture for cattle, the ability of the forest to recover is seriously impaired, destroying the forest for a very long time, if not forever. This kind of unsustainable destructive use affects the earth by taking a large portion of the biosphere out of production - which interrupts the carbon and oxygen cycles, affects local water and soil quality, and causes a decline in the global gene pool by making many species extinct.

Tropical Rainforests are Absorbers of Carbon Dioxide

Oxygen producerIt is sometimes estimated that rainforests provide up to 40% of the oxygen currently found in the atmosphere

Rainforests are important for many reasons. Very importantly, the plants clean the air. By absorbing carbon dioxide they help slow down the greenhouse effect. Rainforest trees store carbon dioxide in their roots, stems, branches, and leaves. Destroying the rainforests causes carbon dioxide to be released, which makes the greenhouse effect worse.