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林带具有积雪作用,早为人们所知,但定量研究尚不多见。1981年12月17、18两日,永定河下游农田防护林区普降大雪。据安次县气象站观测:降雪厚度7厘米,降水量7.6毫米,降雪时伴有4级北偏西风,吹雪现象明显。笔者为了解农田防护林的积雪作用,于20日进行了实地调查。一、调查点概况:调查点设在安次县旧州公社赵各庄村北,即该防护林区西北部边缘的第二网格的麦田内。该网格迎风面主带作为主测林带,树种为29年生旱柳,平均胸径35.3厘米,平
Belt snow has long been known, but quantitative research is still rare. December 1981,18,18 two days, the lower reaches of Yongding farmland shelter belt plunge heavy snow. According to Anzixian weather station observations: the thickness of 7 cm of snowfall, rainfall 7.6 mm, snow accompanied by 4 northwest westerly, blowing snow obvious. In order to understand the role of farmland shelterbelt snow, on the 20th conducted a field survey. I. Survey Point Survey: The investigation point was set up in the north of Zhaogezhuang Village of Old State Commune in Anci County, that is, the second grid of wheat fields on the edge of the northwestern part of the protection forest. The grid windward main belt as the main test forest belt, tree species for 29 years of Salix, the average diameter of 35.3 cm, flat