科尔沁沙地人工固沙植被优化配置模式试验研究

Optimized Modes of Planted Sand-fixing Vegetation in the Horqin Sandy Land

通过对科尔沁沙地7种人工固沙植被配置模式在植物生长季节土壤水分含量、蒸散量和植被盖度的综合分析，优选出可以维持较好的土壤水分状况、形成有效的植被盖度和保障稳定固沙效果的人工固沙植被建立初期的配置模式。结果表明：7种人工固沙配置模式处于人工固沙林定植初级阶段，沙地土壤含水量维持在2.32%～3.41%，基本满足固沙植被水分需求。但在降雨量较低的月份，部分固沙模式土壤含水量表现出较低水平，影响固沙植物的正常生长需求。7种人工固沙植被配置模式蒸散量占同期降雨量94%以上，基本能够维持土壤水量平衡。柠条纯林（525株/hm^2）、山竹岩黄芪＋沙蒿混交（沙蒿2 800株/hm^2、山竹岩黄芪500株/hm^2）、山竹岩黄芪（3 300株/hm^2）的人工固沙配置模式适合初期建立的固沙工程应用。虽然山竹岩黄芪纯林（3 300株/hm^2）固沙模式盖度较高，防风固沙效果好，但由于土壤耗水大，应采取措施，降低其密度。由于小叶杨纯林（1 350株/hm^2）的固沙模式土壤耗水较高、植被盖度低，在固沙初级阶段，相对其他6种固沙模式，综合效果较差。

By analyzing the soil moisture content, evapotranspiration and vegetation coverage under 7 modes of planted vegetation in growing season, the preferred modes of planted vegetation were optimized, and these modes could be used to maintain the good soil moisture conditions, efficient vegetation coverage and ideal effectiveness of sand stabilization in the Horqin sandy land. Soil moisture content varied in a range of 2.32% -3.41% and could basically satisfy the water consumption for plant growth at the early stage of sand fixation. It, however, was low in dry season, and the normal growth of vegetation was impacted. The proportion of evapotranspiration under the 7 modes of planted sand-fixing vegetation occupied over 94% of rainfall, and the balance of soil moisture content could be basically maintained. The planted sand-fixing plantations including the pure Caragana korshinkii shrub- bery （525 plants/hm^2 ）, mixed plantation of Hedysarum fruticosum （500 plants/hm^2 ） with Artemisia desterorum （2 800 plants/hm^2） , and Hedysarum fruticosum shrubbery （3 300 plants/hm^2） were good for popularize in the study area. The planting density of pure Hedysarum fruticosum （3 300 plants/hm^2 ） was high, but the water con- sumption was also high, so some measures should be taken to reduce its density. The sand-fixing effect of pure Populus sirnonii Cart. （ 1 350 plants/hm2 ） was relatively poor because of its high soil moisture consumption and low vegetation coverage.