植物根系占位对土壤热湿迁移的影响

将土壤床作为非饱和多孔介质，考虑土壤内热、湿、气的耦合迁移机制，针对根系占位或不占位两种情况，对植物根系土壤床中的传热传质进行数值模拟，比较土壤中各量场的分布，分析植物根系占位对土壤床内热量及水分迁移的影响，计算和分析结果表明，植物根系的占位对土壤床内水分迁移有明显的影响，根系的存在使土壤内部的水分分布更为均匀，有利于水分向植物根系密集的上层土壤迁移，也有利于水土保持。

Influence of plant roots on heat and moisture migration in vegetation soil bed

The mechanism consisting of heat, water and gas migration was considered. In this mechanism, the soil was regarded as unsaturated porous media. According to the numerical simulation for heat and mass transfer in the vegetation soil bed at two different conditions, one was for the content of plant roots in soil considered and the other was not. The effect of root-occupation in soil on heat and moisture migration was analyzed. The results indicated that the content of plant roots in the vegetation soil bed influenced the migration of water in soil evidently. The existence of plant roots improved the uniformity of moisture distribution, and more water could run to the upper part of soil bed where exists more plant roots. This was beneficial to hold water in soil.