Category Ecology

HOW IS THE SPARROW IMPORTANT IN MAINTAINING A HEALTHY ECOLOGICAL BALANCE?

Sparrow serves the ecosystem of the earth. Sparrows mostly prefer seeds of millet, thistle, weed and sunflower seed. However, they also eat fruits and berries. During this process, sparrows spread seeds to places away from the fruit tree. This is important for germination of the seeds, because if the seeds fall close to the parent plant, they would have to compete for nutrition with the mature plant. This would reduce the chance of germination of the seed as well as growth of the plant once the seed germinated. By spreading seeds, sparrows help the survival of many plants that are the producers in an ecosystem.

Although primarily seed-eaters, sparrows also feed on small insects and worms such as caterpillars, beetles and aphids. Some of these creatures destroy certain plants. Sparrows keep their population in check; otherwise, the insects would have eaten certain plant species to extinction. Here also sparrows play an important role in preserving the ecosystem.

Most birds of prey, such as eagles and falcons, eat other smaller birds. Snakes, which are also secondary consumers, are known to eat sparrows. For example, sharp-shinned hawks prefer sparrows for food.. Hence by providing food for the secondary consumers, sparrows play an important role in their survival and in preserving the ecosystem.

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CAN IT SNOW IN THE SAHARA?

While snow is present in Africa at very high elevations, snow in the Sahara Desert is a very rare event. 

The Sahara Desert is an extremely hot and arid region.  An area about 3,600,000 square miles (9,200,000 square kilometers), the desert is about the size of the United States and stretches across much of North Africa. 

Winter is the season when any rainfall might fall in this area.  The air above the desert is so dry, that often rain doesn’t reach the ground or arrives in very small quantities. 

There have been three recorded episodes of significant snowfall.  The first was recorded in 1979, the second in December of 2016, and the third in January 7, 2018. 

On January 7, 2018, about 10 to 30 centimeters (4 to 12 inches) of snow covered the desert higher elevations above 1000 meters. The snow lasted for less than a day thanks to warming temperatures.

Credit: GEOGRAPHYREALM

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WHICH IS THE WORLD’S YOUNGEST DESERT?

The Aralkum Desert, in Uzbekistan and Kazakhstan. It was once a water body called the Aral Sea, but water from the two rivers that fed it was diverted for agriculture and, gradually, by 2000, most of the sea had become a desert.

The white salt terrain left behind by the desiccation of the southern Aral Sea is now known as the Aralkum Desert. 

At around 17,000 square miles (45,000 square kilometers), the Aralkum Desert is the world’s youngest desert, created entirely due to man-made disturbances. The desolate area has replaced a once vibrant fishing and tourist industry. With the climate mitigating effects of the Aral Sea diminished, winters are now colder and summers hotter.

The Aralkum Desert lies in the path of a powerful east-west airstream and these pollutants have been carried as far away as Antarctica.  Known as Black Blizzards, these powerful wind sorts carry dust pollutants from the Aral Sea over thousands of miles away; Aral dust has been found in the bloodstream of penguins in Antarctica, in the glaciers of Greenland, and in Norway’s forests.

Credit: GEOGRAPHYREALM

Picture Credit : Google

WHAT IS A SAND DUNE?

When grains of sand pile up to form a mound or ridge, it is called a sand dune. Dunes are usually formed by wind blowing the sand in one direction. They can be of various shapes and sizes, including crescents, stars, and long ridges called seifs.

Sand dunes are some of nature’s most scintillating creations. These eye-catching land masses are found around the globe in different climatic conditions. They are not only limited to deserts, but can form in any landscape on the earth’s surface provided the conditions are right. Every sand dune is formed as a result of the interaction between the wind and soil in the form of sand grains. There are many ways thrill seekers can explore sand dunes, for example, sliding down the dunes, Bird viewing in wetlands, skiing, sand boarding or just sledging on the sand slopes. Sky divers or those on airplanes experience the true beauty of sand dunes.

A Sand Dune is a small ridge of hill of sand found in a desert or on top of a beach. When they form on a beach, they are typically above the normal maximum reach of the waves. They form from millions of finely divided sand particles that are blown by the wind and get deposited against some obstacle such as a piece of drift wood, bush or rock.

Credit: EARTH ECLIPSE

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WHERE DID THE SAND IN THE DESERT COME FROM?

Today’s deserts were not always arid lands, and their soil was held in place by plants and trees. But when vegetation dies out, the soil is exposed to erosion. Gradually, the lighter clay and dried organic particles are blown away by the wind, leaving behind grains of sand made up of small particles from eroded rocks.

Sand consists of small particles of larger rock that’s been eroded. But erosion doesn’t happen fast enough in arid environments to be the only cause of desert sand.

Nearly all sand in deserts came from somewhere else – sometimes hundreds of kilometers away. This sand was washed in by rivers or streams in distant, less arid times – often before the area became a desert.

Once a region becomes arid, there’s no vegetation or water to hold the soil down. Then the wind takes over and blows away the finer particles of clay and dried organic matter. What’s left is desert sand.

Finding the exact origin – the source rock – of a desert’s sand can be difficult. Scientists might look for the origin by following dried riverbeds upstream or by tracking the “footprints” that sand left as it traveled – for example, streaks on the faces of boulders left behind by blowing sand in centuries past.

Sometimes an entire desert has migrated due to movement of Earth’s huge overlying land plates. When that’s happened, pieces of the same source rock are sometimes discovered on both sides of a fault line. When scientists identify a potential source rock, they match it to sand grains by its age and composition.

Credit: Earth Sky

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WHY ARE DESERTS ARID?

Deserts are dry for different reasons depending on where they are. Winds in sub-tropical deserts, such as the Sahara in northern Africa, prevent rain clouds from forming. Coastal deserts, like the Atacama in Chile, get no rain, just a little moisture from fog. Death Valley, in California, USA, is a rain shadow desert on mountainsides that face away from rain-filled winds. The Gobi, in Mongolia, is an interior desert; rain-bearing winds cannot reach so far inland. Polar deserts, such as the Arctic and Antarctic, are dry because the water is locked as ice.

Areas that receive less than 25 centimeters (10 inches) of rain annually are called deserts. Deserts are dry with sparse vegetation. Landforms tend to have angular features because the lack of rain results in minimal chemical weathering, and flash floods create steep?walled scarps and gullies. There are few plants to protect the soil from the wind, so the soil is blown away to expose the rocky surface. Even in such a dry climate, most of the landforms are carved by the rare periods of heavy rainfall that result in flash floods, erosion, and sediment deposition.

Hot air rises at the equator, where the land receives the greatest amount of the sun’s radiation. Most of the world’s deserts are located near 30 degrees north latitude and 30 degrees south latitude, where the heated equatorial air begins to descend. The descending air is dense and begins to warm again, evaporating large amounts of water from the land surface. The resulting climate is very dry.

Other deserts are located in the rain shadows of mountain ranges. As moist air passes over a mountain range, it expands and cools, precipitating most of its moisture as it rises. As it sweeps down the other side of the mountain range, it warms and compresses, causing high evaporation rates and shedding little rain. Many of the deserts in the southwestern United States are the result of rain shadows.

Credit: Cliffs Notes

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