科尔沁沙地不同密度小叶锦鸡儿灌丛水量平衡研究

根据沙地水分平衡理论推算了不同栽植密度下小叶锦鸡儿灌丛的蒸散量.结果表明，小叶锦鸡儿灌丛生长期土壤水分含量随着植被密度增加而降低，0.5 m×1 m、1 m×2 m密度植被区平均土壤含水量低于凋萎湿度(1.55%)，2 m×2 m密度植被和天然小叶锦鸡儿植被平均土壤含水量保持在1.60%以上，能够满足植被生存和生长的水分需求.蒸散量随着植被密度增加而增大，以0.5 m×1 m密度灌丛区最高，为297.81 mm，占同期降水量的97.90%；2 m×2 m密度灌丛区最低，为279.71 mm，生长期末期土壤水分节余为24.49 mm.依据生长期土壤水分状况和水分平衡要求，科尔沁沙地小叶锦鸡儿灌丛适宜密度应为2 m×2 m.

Water balance of different density artificial Caragana microphylla shrubs in Horqin sand land

Employing water balance equation, this paper estimated the evapotranspiration of different density Caragana microphylla shrubs during their growing season. The results showed that during this season, the soil water content under artificial C. microphylla shrubs decreased with their increasing planting density. The average soil water content of 0.5 m x 1 m and 1 m x 2 m density artificial C. microphylla shrubs was below wilting humidity (1.55%), while that of 2 m x 2 m density and natural shrubs was kept above 1.60% which could meet the demand of shrubs growth. The evapotranspiration increased with increasing planting densities, being the highest (297.81 mm) in 0.5 m x 1 m density artificial C. microphylla shrubs, which accounted for 97.90% of the total rainfall during growing season, and the lowest (279.71 mm) in 2 m x 2 m density shrubs. By the end of growth phase, soil water content had a surplus of 24.49 mm. According to the soil water status and water balance theory, the appropriate planting density of C. microphylla shrubs in Horqin sand land should be 2 m x 2 m.