文档介绍：All This Carbon Dioxide is Making Me Hungry
二氧化碳能增加食欲?
伊利诺伊大学的研究人员在《美国国家科学院院刊》(PNAS)网络版发布的一项最新研究报告显示,大豆类作物的抗虫害能力正随着二氧化碳含量的增多而逐渐减弱。这项研究是利用伊利诺伊大学的大豆开放式空气浓度增高研究平台进行的。这个开放式实验室可以让大豆种植田内的植物暴露在不同浓度的二氧化碳和臭氧环境中,但又不会与雨水、阳光以及害虫等其它环境影响因素隔绝开来。高浓度的二氧化碳可以促进植物的光合作用,使植物叶片中碳水化合物增加,从而改变碳元素和氮元素的比例。研究人员认为,这种碳与氮的比例变化会影响到害虫。他们认为,害虫会通过吃掉更多叶片来满足自身的氮需求。对比实验结果显示,在二氧化碳浓度高的环境中,大豆的虫害情况更加严重,豆田中成年日本甲虫和西方玉米食虫的数量明显增加,亚洲大豆蚜虫虫害爆发时的害虫数量也更多。
Carbon dioxide is a potent greenhouse gas.
Levels of carbon dioxide, or CO2, in the atmosphere are increasing at an unprecedented rate. But what impact do higher CO2 levels have on plants?
Plants use CO2 from the air along with sunlight and water to produce carbohydrates they use for energy. This process is called photosynthesis.
Higher atmospheric CO2 increases the rate of photosynthesis, and thus the amount of carbohydrates in plant leaves. Sounds beneficial, right? However, scientists have found that as CO2 levels go up, plant defenses might go down.
Researchers at the University of Illinois used a special open-air research facility that allowed them to grow soybean plants in different concentrations of CO2—without changing other factors such as sunlight, insects or rainfall.
They discovered that soybeans grown in fields with higher CO2 levels had much more insect damage and attracted more adult insect pests than those in plots with less CO2 in the air.
The insects