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1986年春,我们分别在黄土型沟底、阴向沟坡、阳向沟坡、阴向峁坡(斜坡)和阳峁坡(斜坡)等五个不同立地类型上设置了白榆造林对比专题试验。试验设在绥德县中角乡景家沟村。该地为丘陵沟壑区,水土流失严重,具有黄土高原丘陵沟壑区特有的地形地貌,土壤为黄土母质上发育的黄绵土(淡粟钙土)。1985年秋进行了鱼鳞坑整地。试验地选择了面积为0.03—0.2公顷5块。1986年4月1日采用常规造林方法在所选择的试验地中分别栽植71株、98株、125株、374株和329株,并设置了保护行。当年6月9日进行第一次成活率调查,10月17日进行了第二次。以后于每年秋季树木停止生长后调查了高、径生长量,并进行了数理统计分析。结果如下:1.五个立地类型成活率和保存率高低依
In the spring of 1986, we set up the special trial of afforestation of Ulmus pumila on five different site types, loess ditch bottom, overcast ditch slope, sunward ditch slope, overcast slope slope and Yangyang slope (slope) . The experiment is located in Jingjiagou Village, Zhongjiao Township, Suide County. The area is a hilly and gully area with severe soil erosion. It has the unique topography of the hilly and gully area in the Loess Plateau. The soil is loessial soil (pale-earth calcareous soil) developed on the loess parental material. The autumn of 1985 fish scale pit site preparation. The area of 0.03-0.2 hectare was selected experimentally. On April 1, 1986, 71 strains, 98 strains, 125 strains, 374 strains and 329 strains were planted in the selected experimental sites by the conventional afforestation method, and the protection lines were set up. The first survival rate survey was conducted on June 9 of the same year and the second was conducted on October 17. After the trees stopped growing in autumn every year, the height and diameter growth were investigated, and the mathematical statistics were analyzed. The results are as follows: 1. The five site type survival rate and the preservation rate according to