Studies on the Time-Varying Effect of Root Morphology and Soil Reinforcement of Two Kinds of Herbs

摘要

The roots can significantly increase the soil reinforcement of vegetation, and the fractal theory provides a new perspective for vegetation roots studies. This article applied the Fractal Fox software to calculate the fractal dimension of alfalfa and cynodon dactylon roots in different growth periods and proved that the two species show fractal characteristics. The conclusions from the analysis are as follows: 1. The fractal dimensions of the two plant roots tend to be stable with the increase of growth period; 2. The fractal characteristic value of cynodon dactylon root is more significant than alfalfa root; 3. Compared with alfalfa root, cynodon dactylon root is more effective in increasing the shear strength of soil. Root system is the only bridge to achieve conversion utilization of material and energy between vegetation and soil. It plays an extremely important role in the soil structure improvement, fertility and productive forces development. Meanwhile, root system has significant effects on soil reinforcement and positively meaning to improve soil anti-erosion and shallow stability of slope. But because plant roots grow in soil that is out of sight, and their distribution and growth structure are quite complicated, so there are some distances between study and actual demand of root morphological structure. In the previous studies, the researchers employed the measurement indexes of root-area ratio, dry weight and fresh weight which could reflect the growth of root in some extent, but they were hard to response changes of morphology and structure of root and very difficulty to be measured. The emergence of fractal theory provided a new measure to realize complex structures and be paid attention gradually. This paper based on fractal theory and study from the perspectives of fractal dimension of roots to study the fractal characteristics of alfalfa root and cynodon dactylon roots which have been widely used in slope ecological protection engineering varies with time.