植物在生长受胁迫的生态系统中，根系往往出现过量增长现象，这就是生物学的冗余现象，也是植物对环境变化的生态适应性表现。这种适应性的形成是在胁迫刺激时，植物形成的新的适应性跃变，这些过量增长的根系对潜流湿地的高效稳定运行意义重大。申请人既往的研究发现：当潜流湿地床深大幅减少后植物根系过量生长，湿地中溶解氧浓度大幅升高，污染物去除效果和稳定性明显改善，但其机理尚未解明。拟通过对根系垂向生长空间的胁迫，建立应激响应与根系及植株体冗余的相关性，阐明生长冗余机理；根据多种胁迫时的冗余耐性分析、冗余抗逆性和遗传特征，识别关键胁迫因子，建立诱导植株个体根系冗余稳定发生和形成高效根构型的人工干预技术体系，构建最佳根系冗余度模型；解析冗余度与植物类型、植物不同生长阶段、填料类型、污染物及水力负荷、根圈微生物类型和数量及活性、填料床氧化还原条件和溶解氧变化的相关性，进而优化关键设计和运行参数，大幅减少工程投资。

A phenomenon of plant roots overgrowth, which is so-called redundancy in biology, usually occurs when the plant is subject to a stress from the ecological environment. It is also the ecological adaptability of plants to environmental changes. This adaptation is a new adaptive transition of plants during the stress stimulation. The overgrowth of the root system is of great significance to the efficient and stable operation of the subsurface flow constructed wetland (SSFCW). The applicant’s previous study found that when the substrate depth of SSFCW decreased dramatically, the plant root overgrew, the dissolved oxygen concentration in SSFCW increased significantly, and the pollutant removal efficiency improved significantly. However, the mechanism of the phenomenon remains unclear. The relationship between stress response and the redundancy of root and plant body will be established and the mechanism of growth redundancy will also be clarified by the limitation on the vertical growth space of roots. According to the analysis on redundancy tolerance, redundancy resistance and hereditary feature, the key stress factors will be identified; and then, a technical system of manual intervention will be established to induce the effective redundancy and configuration of roots of individual plant under a variety of stress. It will be clear by understanding the correlations between redundancy degree and changes, such as plant type, growth stage, medium type, pollutant loading, hydraulic loading, type and quantity and activity of rhizosphere microorganisms, redox conditions and dissolved oxygen in substrate, etc. Based on the above research results, the optimization of the key design and operating parameters and the investment reduction will be performed.