According to legend, in the second half of19th century, Xiang Bing, led by him, came to the northwest desert, feeling dry, lifeless and unaccustomed. So Zuo Gong ordered the army to build roads and plant poplars, willows and Elaeagnus angustifolia trees all over the avenue, suitable forest zone and roads near the city, named Daoliu. Its purpose is: firstly, to reinforce the subgrade; The second is to prevent wind and fix sand; Third, limit the pace of troops and horses; Fourth, provide shelter for pedestrians; Wherever we go, we should mobilize the military and civilians to plant trees, and formulate measures to protect forests and strictly implement them. According to Zuo Gong's own records, there are 264,000 living trees from Changwu County, which borders Shaanxi and Gansu, to Huining, Gansu. Since ancient times, it is the most difficult to plant trees in Hexi. However, under the advocacy and supervision of Zuo Gong, to the west of Jingzhou, the wonders of the Great Wall with thousands of miles of green roads and willows have actually taken shape. Time is merciless. It has been more than 40 years since Zuo Yu 187 1 ordered tree planting. It is not easy to meet the willow planted by Zuo Gong. According to records, according to the statistics from 65438 to 0935, there were 7978 Zuogongliu plants in Pingliang, while the Gansu Forest published from 65438 to 0998 recorded that there were only 202 Zuogongliu plants in the whole province, most of which were in Liu Hu Park, with 187 plants. It seems that Liu Hu has been twice in the past ten years, and this is indeed the place where the public interest is the leftmost. But 1998 has been 15 years. The stars are shifting, the trees are scattered, and the left is still sharply decreasing.
The general refused to return to the border, the children of Huxiang filled the Tianshan Mountains, and newly planted willows for three thousand miles, which attracted the spring breeze. Poems by Yang Changjun, an old subordinate of Zuo and a fellow countryman. When he passed Gan Xin Street, he saw the willows planted by Xiang Army along the way. In addition to the Gobi, it is continuous and touches the ground. He praised Zuo Gong's feat of mobilizing the children of Xiangjiang River to plant elm willows widely and afforest the border areas during the Western Expedition, which yielded results along the way.