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一、试验的依据 张家口地处冀西北山地,位于北纬39°26′至42°8′,东经113°50′至115°27′。北部坝上是内蒙高原的一部分,海拔在1300—2100米之间。坝下山峦起伏,地形复杂,海拔在600—1800米,蔚县境内的小五台山最高蜂达2870米年平均气温1.2℃—9.1℃,无霜期81—149天。年降水量380—480毫米,但集中在7—8月份。海拔高,气温低、无霜期短。在1976年赤城县第一次飞机播种油松造林成功以后,陆续在
I. Test Basis Zhangjiakou is located in the mountainous area of northwestern Hebei Province, between latitudes 39 ° 26 ’and 42 ° 8’ and longitude 113 ° 50 ’to 115 ° 27’. The northern dam is a part of Inner Mongolia plateau, at an elevation of 1300-2100 meters. Dam under the hills and downs, complex terrain, at an elevation of 600-1800 meters, Yuxian County, the highest peak of Mount Wutai 2870 meters, the average annual temperature of 1.2 ℃ -9.1 ℃, frost-free period 81-149 days. Annual precipitation 380-480 mm, but concentrated in the July-August. High altitude, low temperature, frost-free period is short. After the success of the first plane planting pine planted in Akagi in 1976, one after another