杉檫混交根系效应的研究

In this paper,the root system and their associated effect of mixed forest of Cunninghamia lanceolata and Sassafras tsumu at eight-year-old were investigated and analyzed.The results showed that Sassafras tsumu might play a important role in improving the root system of Cunninghamia lanceolata growth due to the single root weight of Cunninghamia lanceolata in mixed forest of Cunninghamia lanceolata and Sassafras tsumu was evidently more than that of Cunninghamia lanceolata in pure forest,and that there were different mixed effects in mixed forest of Cunninghamia lanceolata and Sassafras tsumu in different slope situation,which meant that the associated effect was better in higher slope situation than in lower slope situation,and which reflected in the effect of Sassafras tsumu to the height and D.B.H. growth of Cunninghamia lanceolata. This study indicated that the associated effect was positively related to the effect of roots system.

林草混交根-土复合体的抗剪强度特性

通过对香根草和小叶女贞两种不同植物根系构成的根土复合体及两种植物混交根系构成的根土复合体分别进行了系列直剪试验研究,探索了在不同含水率及不同含根比的情况下,植物根系对复合体抗剪强度的影响规律。研究表明,草本植物香根草以及木本植物小叶女贞的根系都能提高根土复合体的抗剪强度,但二者对复合体抗剪强度指标的贡献是不同的,且混交根土复合体的抗剪强度仍符合库伦强度理论。在此基础上,本研究提出了根土复合体的内摩擦角随小叶女贞含根比变化的幂函数关系式。以上研究为进一步探索林草一体化高稳定护坡技术,具有重要的理论意义。

如何在课外探究实践活动中提升学生的生物科学素养

为解决学生在认识和研究植物生物学特性过程中的关于某些特例不在现有的概念和范畴中的困惑,以学生在课外探究实践活动中发现的榕树植物根系类型等特例难于归属的问题为例,通过搜集佐证资料,提出了值得商榷的增置混根系这一植物根系新类型的建议,并对相应概念进行了描述,由此提升了学生的生物科学素养.