<正>在木材采运系统中，物质漉可分为木质流、生物质流、养分流、土壤流和水分流，能量流推动物质流的流动和转换用输入、排放、输出3股物质流组成的本质流图，反映出木材呆运系统各工序内部和工序之间的物质流动，可{于析年统的立木费源效率和环境负荷、采用输入、输出、加入、损失、回收他用5股能量流组成的能量流图，反映出系统各工序内部和工序之间的能量流动，可用于分析单位能耗和能量效率。。对原木采集生产过程进行分析，得出采集系统中各物质流之问的相互关系以及物质流与能量流的耦合关系。

Effects of mulching weights and materials on dynamic of phosphorus contents in rhizospheric soil of poplar plantation were investigated in this paper. The results showed that the contents of total P increased with the increasing of mulching materials. The contents of total P after the treatment with 2.5, 5.0, 7.5 kg/m2 were 10.77%, 13.85%and 52.31%higher than that in control respectively. There were little differences among different mulching materials, but the contents of total P mulching with them were higher than that of the control. The contents of available P in rhizospheric soil obviously increased after mulching. The contents of available P rised as mulching weights increased. Mulching materials had remarkable effects on the contents of available P. C. nepalensis and L cylindrical vat. major were superior to Q. fabric and P. aquilinum var. latiuscukum. The effects of mulching materials on dynamic of phosphorus contents in rhizospheric soil were similar to mulching weights. It was found that the contents of total P and available P decreased from April to July, then increased from July to December after biological mulching.