Emissions mostly come from vehicle exhausts(排气), factories, artificial fertilizers(肥料) and animal waste from intensive farming. The reactive nitrogen they emit to the air disrupts the environment in two ways: It can make acidic soils too acidic to support their previous mix of species. But primarily, because nitrogen is a fertilizer, it favors wild plants that can maximize the use of nitrogen to help them grow.
In effect, some of the nitrogen spread to fertilize crops is carried in the atmosphere to fertilize weeds, possibly a great distance from where the chemicals were first applied.
The effects of fertilization and acidification favor common aggressive species like grasses, brambles and nettles. They harm more delicate species like mosses(苔藓), and insecteating sundew plants.
The report said 60% of wildlife sites were now receiving a critical load of reactive nitrogen. The report's lead author, Dr. Kevin Hicks from the University of York's Stockholm Environment Institute(SEI), told BBC News that England's Peak District had a definitely low range of species as a result of the reactive nitrogen that fell on the area.
“Nitrogen creates a rather big problem that seems to me to have been given too little attention,” he said. “Governments are responsible for protecting areas like this, but they are clearly failing.”
He said more research was needed to understand the knockon effects for creatures from the changes in vegetation accidentally caused by emissions from cars, industry and farms.
【2012高考二轮复习英语专题训练(江苏专用)专题2 阅读理解21】相关文章:
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第20组(含解析)
★ 【三维设计】2017届高考英语(江苏专用)二轮复习素材:高考单词5.高中英语常见词组
★ 2017年高考英语二轮复习精品资料:专题14 阅读理解(教学案)(原卷版)
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第15组(含解析)
★ 2017届高考英语二轮复习书面表达限时测验:4(含解析)
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第13组(含解析)
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第18组(含解析)
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21