(MUSIC)
VOICE ONE:
You may wonder how anything can live in this extreme environment of a white sand desert. There is not much rain. The heat in summer is intense. The sand lacks nutrients.
Yet almost four-hundred kinds of animals live in White Sands National Monument. Many of them are birds or insects. There are also twenty-six kinds of reptiles, including rattlesnakes and lizards. And there are more than forty kinds of mammals. They include rabbits, foxes and coyotes.
Scientists know that plants and animals often change to be able to live in extreme environments. For example, they change color to protect themselves from enemies. Many of the animals that live in the sand dunes have become white. So it is difficult to see the animals in the sand.
There is another reason why you may not be able to see the animals. Many of them remain underground during the day when it is very hot. They come out at night when it is cooler. You may be able to see their footprints.
VOICE TWO:
Plants do grow in the White Sands dune field. But even plants that grow in most deserts have trouble surviving. A major reason is that the dunes bury any plants in their way as they move across the desert. Yet, a few plants have developed techniques to avoid being buried by moving sand.
For example, some plants grow taller and their roots grow deeper into the sand. The soaptree yucca plant can make its stem grow longer to keep its leaves above the sand. The plant grows up to thirty centimeters a year.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25