科尔沁沙地东部农牧交错带土地承载力研究--以科尔沁左翼后旗为例

科尔沁左翼后旗位于科尔沁沙地东部农牧交错带，生态环境复杂、脆弱，资源、人口和环境的协调发展至关重要，其土地承载力状况是协调三者关系的重要依据。本文应用系统动力学原理，以1995年为起始年份建立了系统动力学模型(SD模型)，包括人口、土地资源、种植业、林业、畜牧业、渔业和消费等7个子系统。选择3种人口增长速度和3种营养水平组成9种方案，通过模型的运行预测了科左后旗未来50年人口的动态变化和最大土地资源承载力，并对1995—2000年实际的人口发展状况和生态状况进行了讨论。研究显示，科左后旗土地承载力46．7l—74．5l万人，不同的方案达到最大承载力的时间不同，指出控制人口增长是实现经济环境协调发展的必要条件，科左后旗的实际人口增长控制较好，现有的环境问题是不合理的开发活动造成的。

Land capacity in agriculture-grazing ecotone of east Keerqin lands-the case of Keerqinzuoyihouqi county

Keerqinzuoyihouqi is located in agriculture grazing ecotone in northeast Keerqin lands. On account of the complex and fragile environment, it is important to harmonize the relationship among population, resources and environment. Land sources capacity became important in settling the problem. In this paper, a dynamic model was established, including population, land resource, planting, husbandry, fishery and consumption subsystems. Across 9 scenario, i.e.,3 development rate * 3 nutrition level , the model predicts changes of population and maximum land resource capacity in the future 50 years. The actual population increase and ecological environments were further discussed. The results showed that the land capacity for population ranges from 467,100 to 745,100 and the intervals to maximum capacity are different among different scenarios. So population control is necessary for economic development and environment protection. In fact the population inscrease rate is rational. The environment questions is caused by irrational development.