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在水土流失严重的晋西黄土山区,由于土地利用不合理,加之乱垦滥牧,天然植被保存无几,林地复盖率大约12％左右。每平方公里年土壤流失量达1～1.5万吨之多。为了增加这类地区森林复盖率,必须营造各种防护林。森林能保持水土、涵养水源、防风固沙、提高土壤肥力、改善小气候。晋西不少地区,三料(饲料、肥料、燃料)俱缺,是影响农业生产发展的顽症。由于土壤贫瘠和干旱,适于栽植灌木。灌木枝干小,根系发达,萌蘖丛生性强,
In the western Shanxi Loess Plateau where soil and water loss are serious, due to unreasonable land utilization and overgrazing of pasture, there are few natural vegetation, and the coverage rate of forest land is about 12%. The annual soil loss per square kilometer up to 1 to 15,000 tons. In order to increase the coverage of forests in such areas, various shelter forests must be created. Forests can maintain water and soil, conserve water, wind and sand, improve soil fertility, improve microclimate. In many parts of Shanxi Province, three materials (feed, fertilizer and fuel) are all defects that affect the development of agricultural production. Due to poor soil and drought, suitable for planting shrubs. Small shrubs branches, developed root system, sprout bushy strong,