松嫩平原碱化草地植物－环境系统的仿真模拟

本研究以系统仿真的方法对松嫩平原碱化草地植物－环境系统进行模拟。模型的系统变量包括植物种的地上、地下生物量，土壤水分、有机质、可溶性和交换性Ｎａ￣＋和Ｃａ￣＋＋浓度和植物的凋落物生物量。模型所考虑的过程有：不同土壤碱化条件下的植物生长季节动态；土壤水、盐运动；植物的蒸腾作用；土壤表面的蒸发；凋落物的积累和分解；土壤有机质的积累和矿化；地下生物量对土壤持水和导水特性的控制作用，以及收获强度对系统平衡的影响等。模型成功地解释了植物生物量形成过程与环境之间的动态耦合、相关作用。模拟结果说明：与地下生物量密切相关的土壤非毛管孔隙度与土壤的碱化和脱碱过程有极强的相关作用，这种作用是通过改变土壤的饱和持水量来实现的。非毛管孔隙度随地下生物量增加．导致饱和含水量增加和脱碱作用加强。收获强度过大导致地下生物量的减少、非毛管孔隙度的减少和碱化作用的加强。

A SIMULATION MODEL FOR THE PLANT-ENVIRONMENTAL SYSTEM OF ALKALIZED GRASSLAND ON SONGNEN PLAIN IN NORTHEAST CHINA

A differential equation system model was proposed and implemented to simulate the dynamic interactions between the plants and soil variirbles such as water and main salt element concentrations on the alkalized grassland On son-gnen plain in Northeast China. The system variables in the model included Above and underground biomass of major plant species, soil water content, soil organic content, and soluble and exchangeable cation concentrations of sodium and calcium in the soil. The processes considered in the model included soil cation and water movement, plant growth under different soil alkality,plant transpiration and soil evaporation, liter accumulation and decomposition,and soil organic matter accumulation and mineralization The modei emphasized the effects of underground biomass on soil moisture characteristics and soil hydraulic conductlvity and successfully explained the couplingbetween the biomass and soil environment