浦阳江下游江岸草本植物根系对土壤抗冲性的影响

采用7级目测法对浦阳江下游江岸草本植物进行了调研，筛选出了当地的优势草本，并对其根系密度、土壤抗冲性增强效应进行了分析，补充了植物根系对江岸土壤抗冲性影响的基础资料。研究发现:（1）浦阳江下游江岸的优势草本植物是狗牙根、水蓼、芦苇、芒、双穗雀稗；（2）5种草本植物根系（d≤1.0 mm）在土壤表层（0—30 cm）均有较多分布，根系密度随着土层的垂直分布深度增加而减少，其规律服从指数函数关系分布；（3）5种优势草本根系均能增强浦阳江下游江岸土壤的抗冲性，增强值分别如下:芦苇14.16，芒12.53，狗牙根5.39，双汇雀稗5.01，水蓼4.41。5种优势草本均能在浦阳江消落带植被构建中发挥土壤抗冲性增强效应，尤其是芦苇与芒的增强效应最为明显。

Effect of the Root Systems of Herbaceous Plants on Soil Anti-scourbility in the Riparian Area of Lower Reaches of Puyang River

Puyang River is often affected by the flood disaster. However, herbaceous plants play a key role in control of soil erosion. In this paper, a field survey of species, relative coverage, abundance and relative height for herbaceous plants was carried out in the riparian area of lower reaches of Puyang River. The root densities of dominant plant species, enhancement values of anti-scourability by roots were studied. The results showed that:(1) Cynodon dactylon, Polygonum hydropiper, Phragmites australis, Miscanthus sinensis and Paspalum paspaloides were dominant in herbaceous plants; (2) roots with diameter less than 1 mm of 5 herbaceous plants mostly distributed in 0—30 cm soil surface layer, the root densities decreased with the increase of soil depth, and the relationship of them followed the index series relationship; (3) all the roots of 5 species had remarkable positive enhancement effects on soil anti-scouribility, and the intensified value of soil anti-scourability by root system of Phragmites australis was 14.16, 12.53 for Miscanthus sinensis, 5.39 for Cynodon dactylon, 5.01 for Paspalum paspaloides, and 4.41 for Polygonum hydropiper. In the experiment, it is suggested that these five herbaceous plants, especially Phragmites australis and Miscanthus sinensis, could enhance the soil anti-scouribility for protecting the riparian area of lower reaches of Puyang River.