[by:www.51voa.com] [00:00.00]¸ü¶àÌýÁ¦Çë·ÃÎÊ51VOA.COM [00:00.24]Much of the western United States [00:03.20] is suffering from extreme drought conditions. [00:07.32]U.S. officials are blaming the lack of rainfall [00:11.28]and snow for wildfires and water shortages. [00:16.48]The long drought has influenced changes around an increasing number [00:22.67]of homes in southern California. [00:25.47]More and more people there [00:28.12]are removing traditional garden plants [00:31.43]and replacing them with plants that need less water. [00:36.23] Jan Muntz is one of those homeowners. [00:40.20]She says it has not been easy to replace the plants in her yard. [00:46.52]"It's very painful, and some of these plants have been there probably 80 and 90 years." [00:51.64]Many plants in the Los Angeles area do not grow there naturally. [00:58.12]In other words, they are non-native plants. [01:02.10]Some require lots of water. [01:05.08]The Theodore Payne Foundation has been working for years [01:09.88]to educate Californians about plants that are native to the state. [01:16.16]Kitty Connolly works for the group. [01:19.41]She says there has been a sharp increase [01:22.41]in the number of people who want to learn about indigenous plants. [01:27.96]"You use less water, so in a California native garden, [01:31.44]depending on how you plant, [01:32.96]you'll save 50 to 80 percent of water over a conventional garden." [01:37.08]The foundation operates a nursery [01:40.16]where people learn how to grow and care for native plants. [01:45.28]Scientists are now predicting some weather changes in the American West. [01:51.56]Bill Patzert is a climatologist, a scientist who studies the climate. [01:58.76]He predicts rain will fall in Southern California this winter. [02:04.64]"This looks very, very promising [02:07.00]for a down payment on drought relief in the American West. [02:10.84]We're very hopeful for this El Nino." [02:13.04]The El Nino weather event produces warmer- [02:17.12]than-average waters in the Pacific Ocean, near Earth's Equator. [02:22.68]Scientists expect this weather pattern will be very strong, [02:27.80]beginning at the end of this year and continuing into next year. [02:33.92]Mr. Patzert notes that El Nino also has an effect on other areas. [02:41.08]"Some areas that are normally dry like the American West, [02:44.84]Peru and Ecuador, get torrential rains. [02:47.96]Southeast Asia, Indonesia and the Philippines and northern Australia -- [02:52.75]they get punishing droughts. [02:54.60]Even in South Africa, they get droughts [02:57.24]and so there isn't one continent that doesn't feel the footprint of a big El Nino." [03:04.08]El Nino lasts for about a year. [03:07.72]But another weather pattern is forming, and could last much longer. [03:14.24]It is called the Pacific Decadal Oscillation, or PDO. [03:21.76]Nate Mantua is a research scientist. [03:25.88]He told VOA on Skype that the PDO [03:30.56]could produce warming and cooling patterns for many years. [03:35.40]"The warm pattern of the PDO favors above-normal rainfall in southern California [03:40.68]and throughout the southwest part of the U.S. and northern Mexico, [03:43.84]so it would favor a break in these dry conditions for the Southwest." [03:48.80]Mr. Mantua notes, weather is unpredictable. [03:53.16]He says the southwestern United States [03:56.56]may have only one year of rain. [03:59.98]I'm Marsha James.