久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

 
 
 

From ancient farmers, lessons for today's Amazon

2012-04-18 17:19

 

Get Flash Player

Download

This is the VOA Special English Agriculture Report.

South America's Amazon is the largest tropical rainforest and river system on Earth. But the Amazon is disappearing at the rate of about 800,000 hectares a year. This deforestation is caused by an increase in agriculture and cattle ranching and the building of roads and dams. Another cause is the illegal cutting of trees for logging companies.

Now, a new study says ancient Amazonian farming methods could offer valuable lessons for today. The study looks at the pre-Columbian period. Christopher Columbus and other European explorers began arriving in the Americas in the late 1400s.

The researchers studied a coastal wetland area where ancient farm beds and canals remain unchanged. The site is in French Guyana.

From ancient farmers, lessons for today's Amazon

A widely held belief is that pre-Columbian farmers used a great deal of fire to manage Amazonian ecosystems. But the scientists say their study calls this idea into question. It shows that raised-field farmers limited their burning to improve agricultural production.

Jose Iriarte from the University of Exeter in England was lead author of the study. Mr. Iriarte says fire results in the loss of important nutrients for crops. When land is not being used for farming, periods without fire are most effective in rebuilding soil organic matter and preserving soil structure. "So in this sense," he says, "we interpreted that they were limiting fires because it was better to grow crops in these raised field systems."

He says this fire-free method by the pre-Columbian farmers helped change the seasonally flooded savanna, or grassland, into productive cropland. Raised fields provide better drainage and soil aeration and also hold moisture during the dry season.

This fire-free method of agriculture would have been labor intensive. It ended when up to 95 percent of the native people died from diseases brought by the Europeans. Mitchell Power is curator of the Natural History Museum at the University of Utah.

MITCHELL POWER: "Once the Columbian encounter happens, we don't see that type of agriculture any more. We start to see increased burning and a shift towards dry-land farming. So people were then clearing forests and making their raised beds in the forests. And so, what we think is happening is that there was a huge demographic collapse in this region."

The European colonizers brought slash-and-burn methods of agriculture that remain a threat to the rainforest. Experts say at current rates, more than half of the Amazon's tropical rainforest could be gone by 2030.

The study is in the Proceedings of the National Academy of Sciences. You can find a link at voaspecialenglish.com. And that's the VOA Special English Agriculture Report. I'm Jim Tedder.

savanna: a flat grassland of tropical or subtropical regions 熱帶草原

aeration: the process of exposing to air 通風

Related stories:

Using charcoal to make soil into black gold

A call for equal rights for women farmers

New report finds agriculture promotes African economic growth

Securing rights for women farmers

(來源:VOA 編輯:旭燕)

 
中國日報網英語點津版權說明:凡注明來源為“中國日報網英語點津:XXX(署名)”的原創作品,除與中國日報網簽署英語點津內容授權協議的網站外,其他任何網站或單位未經允許不得非法盜鏈、轉載和使用,違者必究。如需使用,請與010-84883561聯系;凡本網注明“來源:XXX(非英語點津)”的作品,均轉載自其它媒體,目的在于傳播更多信息,其他媒體如需轉載,請與稿件來源方聯系,如產生任何問題與本網無關;本網所發布的歌曲、電影片段,版權歸原作者所有,僅供學習與研究,如果侵權,請提供版權證明,以便盡快刪除。

中國日報網雙語新聞

掃描左側二維碼

添加Chinadaily_Mobile
你想看的我們這兒都有!

中國日報雙語手機報

點擊左側圖標查看訂閱方式

中國首份雙語手機報
學英語看資訊一個都不能少!

關注和訂閱

本文相關閱讀
人氣排行
搜熱詞
 
 
精華欄目
 

閱讀

詞匯

視聽

翻譯

口語

合作

 

關于我們 | 聯系方式 | 招聘信息

Copyright by chinadaily.com.cn. All rights reserved. None of this material may be used for any commercial or public use. Reproduction in whole or in part without permission is prohibited. 版權聲明:本網站所刊登的中國日報網英語點津內容,版權屬中國日報網所有,未經協議授權,禁止下載使用。 歡迎愿意與本網站合作的單位或個人與我們聯系。

電話:8610-84883645

傳真:8610-84883500

Email: languagetips@chinadaily.com.cn

久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

    日本老熟妇毛茸茸| 超碰97免费观看| 性做爰过程免费播放| 欧美一区二区中文字幕| 日韩高清第一页| 大陆极品少妇内射aaaaa| 亚洲无在线观看| 99999精品视频| 青青视频免费在线观看| 性生交免费视频| 青青青在线观看视频| 中文字幕亚洲乱码| 每日在线更新av| 91麻豆天美传媒在线| 91极品视频在线观看| 亚洲 高清 成人 动漫| 欧洲精品视频在线| 亚洲精品第三页| 国产天堂在线播放| 日韩在线一级片| 丁香婷婷综合激情| 欧洲在线免费视频| 国产精品天天av精麻传媒| 每日在线观看av| 国产精品88久久久久久妇女| 亚洲欧美国产日韩综合| 日本在线视频www| www插插插无码视频网站| 米仓穗香在线观看| 在线无限看免费粉色视频| 91蝌蚪视频在线观看| 黄色一级视频片| 99久久久精品视频| 欧美一级中文字幕| 日本一级淫片演员| 五月天婷婷在线观看视频| 久久久久国产一区| 日韩福利视频在线| 欧美性猛交久久久乱大交小说| 国产h视频在线播放| 国产九色porny| 久久成人福利视频| 久久人妻无码一区二区| 久久视频免费在线| 色婷婷777777仙踪林| 公共露出暴露狂另类av| 精品国产无码在线| 亚洲五月激情网| 国产又爽又黄ai换脸| 五月天丁香花婷婷| 日韩av自拍偷拍| 九九九久久久久久久| 国产又粗又猛大又黄又爽| 中文字幕综合在线观看| 日本丰满少妇黄大片在线观看| 日本一本在线视频| 久久久久久久久久久久久国产| 国产欧美自拍视频| 亚洲精品蜜桃久久久久久| 性一交一乱一伧国产女士spa| 欧美中文字幕在线观看视频| 国产一区二区三区小说| av免费观看国产| 无码aⅴ精品一区二区三区浪潮| 97成人在线观看视频| 黄色免费网址大全| 国产免费中文字幕| 可以在线看黄的网站| 人人妻人人做人人爽| 男人操女人免费软件| 五月婷婷之综合激情| 激情五月婷婷基地| 成人在线观看毛片| 成人免费播放器| 国产成人精品无码播放| 亚洲欧美偷拍另类| 亚洲小视频在线播放| 无码粉嫩虎白一线天在线观看 | 国产无色aaa| 欧美大片免费播放| 欧美日韩二三区| 美女网站视频黄色| 97超碰人人爽| 久久手机在线视频| 欧美日韩亚洲一二三| 在线观看日本www| 国产高清www| 一区二区xxx| 欧洲金发美女大战黑人| 美女福利视频在线| www.五月天色| 国产视频一视频二| 中文字幕久久av| 国产精品69久久久| 中文字幕国内自拍| 69精品丰满人妻无码视频a片 | 欧美日韩精品区别| 六月婷婷激情综合| 国产嫩草在线观看| 国产系列第一页| 国产精品丝袜久久久久久消防器材| 91日韩视频在线观看| 久久综合亚洲精品| 亚洲精品高清无码视频| 欧美在线观看黄| 韩国中文字幕av| 男人天堂av片| 日韩av一卡二卡三卡| 免费毛片小视频| 五月天国产视频| 北条麻妃视频在线| 国产成人永久免费视频| 亚洲午夜激情影院| 欧美日韩中文在线视频| 欧美一级免费在线观看| 一本色道无码道dvd在线观看| 日韩高清在线一区二区| 国产黄色特级片| 波多野结衣 作品| 五月天视频在线观看| 北条麻妃在线视频观看| 欧美性猛交内射兽交老熟妇| 欧美在线aaa| 欧美v在线观看| 中文字幕在线中文| 99re精彩视频| 成人免费观看视频在线观看| 欧洲精品视频在线| 成人亚洲免费视频| 久草在在线视频| 99视频在线免费播放| 永久免费在线看片视频| 欧美一级xxxx| 中文字幕有码av| 国产精品亚洲a| 毛片在线播放视频| 一二三四中文字幕| www.久久com| www.com污| 小泽玛利亚视频在线观看| 国产精品第12页| 伊人成色综合网| 人妻夜夜添夜夜无码av| www.日本三级| 久久久天堂国产精品| 欧美少妇一级片| 91热视频在线观看| 中文字幕线观看| 玖玖爱视频在线| 亚洲天堂av线| 激情网站五月天| 欧美aⅴ在线观看| 国产成人亚洲精品无码h在线| 成人网站免费观看入口| 奇米影视亚洲色图| 18禁免费观看网站| 欧美老熟妇喷水| 黄色片视频在线免费观看| 欧美 国产 日本| 亚洲中文字幕无码不卡电影| 国产主播在线看| 久久精品午夜福利| 国产一级做a爰片久久| 精品999在线| 亚洲欧美天堂在线| 成年人黄色在线观看| 一二三四中文字幕| 日韩精品一区二区在线视频| 99久久久精品视频| av高清在线免费观看| 免费黄色日本网站| 日本www高清视频| 手机在线成人免费视频| 国产欧美一区二| 日本一本草久p| www.av91| 精品久久久久av| 欧美美女一级片| 美女黄色片网站| 很污的网站在线观看| 女性女同性aⅴ免费观女性恋| 50路60路老熟妇啪啪| 一道本在线免费视频| av观看免费在线| av动漫在线观看| 黄大色黄女片18第一次| 精品国产无码在线| 蜜臀av无码一区二区三区 | 亚洲色图偷拍视频| 加勒比海盗1在线观看免费国语版| 成人精品视频在线播放| 爱福利视频一区二区| 尤物国产在线观看| 欧洲xxxxx| 国产一区二区网| 最新天堂在线视频| 中文字幕人妻熟女人妻洋洋| 丰满少妇被猛烈进入高清播放| 超碰网在线观看| 深夜做爰性大片蜜桃|