首页
登录
职称英语
Low-level slash-and-burn farming doesn’t harm rainforest. On the contrary, i
Low-level slash-and-burn farming doesn’t harm rainforest. On the contrary, i
游客
2025-04-15
16
管理
问题
Low-level slash-and-burn farming doesn’t harm rainforest. On the contrary, it helps farmers and improves forest soils. This is the unorthodox view of a German soil scientist who has shown that burnt clearings in the Amazon, dating back more than 1 000 years, helped create patches of rich, fertile soil that farmers still benefit from today.
Most rainforest soils are thin and poor because they lack minerals and because the heat and heavy rainfall destroy most organic matter in the soils within four years of it reaching the forest floor. This means topsoil contains few of the ingredients needed for long-term successful farming.
But Bruno Glaser, a soil scientist of the University of Bayreuth, has studied unexpected patches of fertile soils in the central Amazon. These soils contain lots of organic matter. Glaser has shown that most of this fertile organic matter comes from "black carbon"—the organic particles from camp fires and charred(烧成炭的)wood left over from thousands of years of slash-and-burn faring." The soils, known as Terra Preta, contained up to 70 times more black carbon than the surrounding soil," says Glaser. Unburnt vegetation rots quickly, but black carbon persists in the soil for many centuries. Radiocarbon dating shows that the charred wood in Terra Preta soils is typically more than 1 000 years old.
"Slash-and-burn farming can be good for soils provided it doesn’t completely burn all the vegetation, and leaves behind charred wood," says Glaser. "It can be better than manure(粪肥)." Burning the forest just once can leave behind enough black carbon to keep the soil fertile for thousands of years. And rainforests easily regrow after small-scale clearing. Contrary to the conventional view that human activities damage the environment, Glaser says,"black carbon combined with human wastes is responsible for the richness of Terra Preta soils."
Terra Preta soils turn up in large patches all over the Amazon, where they are highly prized by farmers. All the patches fall within 500 square kilometers in the central Amazon. Glaser says the widespread presence of pottery confirms the soil’s human origins. The findings add weight to the theory that large areas of the Amazon have recovered so well from past periods of agricultural use that the regrowth has been mistaken by generations of biologists for "virgin" forest. During the past decade, researchers have discovered hundreds of large earth works deep in the jungle. They are up to 20 meters high and cover up to a square kilometer. Glaser claims that these earth works, built between AD 400 and 1400, were at the heart of urban civilizations. Now it seems the richness of the Terra Preta soils may explain how such civilizations managed to feed themselves. [br] Glaser made his discovery by______.
选项
A、studying patches of fertile soils in the central Amazon
B、examining pottery left over by ancient civilizations
C、test-burning patches of trees in the central Amazon
D、radiocarbon-dating ingredients contained in forest soils
答案
A
解析
根据文章第三段第一句和第三句“But Bruno Glaser,a soil scientist of theUniversity of Bayreuth,has studied unexpected patches of fertile soils in the central Amazon.Glaser has shown that most of this fertile organic matter comes from‘black carbon’——the organicparticles from camp fires and charred(烧成炭的)wood left over from thousands of years ofslash-and-burn faring.”可知,德国拜罗伊特大学的土壤科学家布鲁诺·格拉瑟研究了亚马逊中部的肥沃土壤。其研究表明,大多数肥沃的有机物质来自“黑炭”——篝火留下的有机颗粒以及数千年刀耕火种遗留下来的碳木。据此判断,答案是A。
转载请注明原文地址:https://tihaiku.com/zcyy/4038195.html
相关试题推荐
Heisbynomeansa(n)______man.Onthecontrary,healwaysdepartsfromcustoms
Low-levelslash-and-burnfarmingdoesn’tharmrainforest.Onthecontrary,i
Low-levelslash-and-burnfarmingdoesn’tharmrainforest.Onthecontrary,i
Low-levelslash-and-burnfarmingdoesn’tharmrainforest.Onthecontrary,i
Low-levelslash-and-burnfarmingdoesn’tharmrainforest.Onthecontrary,i
Low-levelslash-and-burnfarmingdoesn’tharmrainforest.Onthecontrary,i
Newtechnologyismakingthetraditionalfarmingmachineryandmethods______.A、e
Thereislittle,_____,farminginthatareaandallyoucanseeismilesofwild
WithoutwaterfromtheNileRiver,Egypt____afarmingcountryandbecomeadesert
Theemperorturnedtoalchemytoensureimmortality.butcontrarytohiswishes,
随机试题
Liquidityriskarisesfromtheinabilityofabanktoaccommodateunexpected
[originaltext]W:Whatkindoftrainingdoesoneneedtogointothistypeofjo
DearSir,Muchtomyregret,Iwritethislettertocomplainaboutyourcomp
下列属于热气溶胶灭火剂灭火原理的有()。A.吸热降温灭火 B.化学抑制灭火
一些追求快速减肥的女性,认为素食是大量食用蔬菜水果,其他什么都不吃。这种错误的膳
左边给定的是纸盒外表面的展开图,右边哪一项能由它折叠而成? A.如上图所示
Thechangeinthatvillagewasmiraculou
药物透过生物膜的转运机制错误的是A.胞饮作用 B.被动扩散 C.促进扩散
上个世纪90年代,中国高性能计算机领域存在的没得用、不适用、用不起的严重问题制约
(2015年真题)火灾爆炸的预防包括防火和防爆两方面。下列措施中,不符合防爆基本
最新回复
(
0
)