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目前,我区延安以北荒山造林树种主要是刺槐,比较单一。为了丰富荒山造林树种,加速荒山绿化,我们先后于1976年、1977年对吴旗县铁边城国营林场杜梨荒山造林作了初步调查,并将调查结果进行了整理。一、自然概况铁边城国营林场位于吴旗县西北部,属黄土丘陵沟壑区,海拔1400～1630米。气候寒冷,干旱多风,最高气温37.1℃,最低气温-25℃,年平均气温7.8℃。年降水量340毫米 (个别年份仅300毫米),全年无霜期100～174天,最大风速34米/秒,经常出现持久的干
At present, the afforested tree species in the barren hills north of Yan’an in our district are mainly Robinia pseudoacacia and are relatively single. In order to enrich afforestation tree species of barren hills and speed up the afforestation of barren hills, we conducted a preliminary investigation into the afforestation of barren hills in the state farm of Tiebian City in Wuqi County in 1976 and 1977, and sorted out the findings. First, the natural profile Tiebian City State Forest Farm is located in Wuqi County, northwest, is a loess hilly and ravine, 1400 ~ 1630 meters above sea level. Cold climate, arid windy, the maximum temperature of 37.1 ℃, the lowest temperature of -25 ℃, the annual average temperature of 7.8 ℃. The annual rainfall of 340 mm (individual years, only 300 mm), the annual frost-free period of 100 to 174 days, the maximum wind speed of 34 m / s, often lasting dry