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联邦德国汉堡的林业科技人员,最近查明了城市马路两旁的绿化树患死症的原因。街旁绿树的枯死,主要是由于城市街道脏水和废弃物的污染,使树木根部的土壤严重盐渍化,从而导致树木日趋枯死。如果重新种植树木或移栽树苗,都将付出昂贵的代价,而且并非一朝一夕即可奏效。为此,除要求人们保持城市街道的环境卫生,限制在绿化树下的人行道上摆摊贩卖饮食和各种污染环境的商品,更重要的是采取科学抢救病树的措施。汉堡的科学人员将一定含量的钙、钾、镁等微量元素制剂,施入林木根部的土壤中,可排除土壤中多余的钠和氯,在短期内就能够使树木重新长得枝叶繁茂。科技人员采用这种方法,曾于1982年在汉堡市抢救活了700多棵濒于病死的绿化树。目前汉堡市的绿化树已大部分返青了,此法值得世界各大城
Forestry scientists in the Federal Republic of Germany have recently identified the causes of the afflictions of greening trees on both sides of urban roads. The death of green trees in the street is mainly due to the pollution of dirty water and waste in the urban streets, causing the soil in the roots of trees to be seriously salinized, thus causing the trees to become increasingly dead. If the replanting of trees or transplanting seedlings, will pay a high price, and not be effective overnight. For this reason, in addition to requiring people to maintain the sanitation of urban streets, restrictions on the sale of food and beverages and various products polluting the environment on sidewalks under tree-lined trees are more importantly measures for the scientific rescue of diseased trees. Burger scientists apply certain amounts of trace elements such as calcium, potassium and magnesium to soil in the roots of trees to remove extra sodium and chlorine in the soil and to make the trees regrowth in the short term. In this way, scientists and technologists used to rescue more than 700 dying green trees in Hamburg in 1982. At present, most of green trees in Hamburg have returned to green, and this method deserves to be in every major city in the world