【摘要】 榆树疏林草原是科尔沁沙地古老的、持续期最长的原生植被 ,具有极强的适应性、稳定性 ,抗干扰能力和恢复能力 ,而且生物产量高 ,它是科尔沁沙地植被演替的顶级群落。榆树疏林草原广布于科尔沁沙地 ,经过长期的破坏 ,已经残缺不全 ,到 1 998年总面积 41 39平方公里。在科尔沁沙地榆树疏林草原是生产力最高的一种草原群落 ,年地上生物产量可达45 0 0 kg/hm2以上 ,而其他类型的草原群落均在 40 0 0 kg/hm2以下。榆树疏林草原具有较高的自然更新能力 ,封育保护以后每公顷可以产生幼苗 6万多株 ,但由于环境的限制幼苗的保存率很低 ,由于水分胁迫 ,加速了树木的死亡 ,这一趋势说明榆树疏林草原的疏林性质是由资源的丰富度来决定的更多还原

【Abstract】 Grassland with sparsed elm was the archaicest and longest-drawn wild vegetation. It were a climax biotic community with stronger stability, anti-jamming and restorable ability and highest biomass. It were distributed all of Keerqin sandy land, but fragmentary by jamming, and only 4139 km 2. The above-ground biomass were 4500 kg/hm 2, and that of other grassland communities were 4000 kg/hm 2. There were some saplings and older trees, more than 60 thousands of new seedlings could be produced per year. But the survival rates of the seedlings, saplings were very low because the environmental limitation. It was showed that the characters of grassland with sparsed elm were mainly determined by abundances of natural resources especially soil moistures.更多还原