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睢宁县地处北温带南缘,冬春气候干旱而寒冷,特别是春季空气湿度很小,苗木失水较快,常造成I—69,I—72杨造林成活率不高。据调查全县造林成活率平均只有70％左右,远远低于本省规定的造林验收标准。为了攻克成活关,我们查阅了国内外有关引种资料,发现凡是栽植时最低气温在0℃以上的,造林就容易成活。如我国的湖南、湖北、江苏以南地区和原产地。而气温在0℃以下的地区成活率普遍偏低。可见造林成活率的高低,不仅与水分有关,而且与气温有密切关系。为此,我们把栽植时间提前到秋末冬初气温尚高、苗木尚未完全休眠前进行
Suining County is located in the southern edge of the northern temperate zone, winter and spring arid and cold climate, especially in the spring air humidity is very small, rapid water loss seedlings, often resulting in I-69, I-72 afforestation survival rate is not high. According to the survey, the average afforestation survival rate of the county is only about 70%, which is far below the provincial acceptance standard for afforestation. In order to capture the survival of off, we have access to the introduction of relevant information at home and abroad and found that when planting the minimum temperature above 0 ℃, afforestation is easy to survive. Such as China’s Hunan, Hubei, south of Jiangsu and the origin. The survival rate of the area below 0 ℃ is generally low. We can see the level of survival rate of afforestation, not only with the water, but also with the temperature are closely related. To this end, we put planting time ahead of late autumn and winter temperatures are still high, seedlings have not fully sleep before