适于深圳城市河道护坡的草类植物筛选

Screening of Grasses for Slope Protection of Urban Rivers in Shenzhen City

通过构建模拟城市河道,测定7种供试植物的盖度、生物量、坡面适应性、根系特征、耐淹能力及抗冲刷能力等,对适于深圳城市河道护坡的草类植物进行了筛选.结果表明:在深圳的自然条件下,各供试植物在模拟河道堤坡上都能正常生长;播种或幼苗移栽4个月后,各物种间的盖度、生物量、根系特征、耐淹能力及抗冲刷能力差异显著;百喜草盖度可达70%以上,生物量(干重)可达8.33 kg/m2,其中根系生物量为2.09 kg/m2,而且直径不超过1mm的有效根多,明显高于其它供试植物;百喜草植株在部分淹水、全淹时半数死亡时间分别为45及15 d,耐淹能力强;百喜草砌块能抵御4.0m/s的流速冲刷.综合各项指标,百喜草是最适于深圳地区城市河道护坡的优良水保草种.

Suitable grasses for the slope protection of urban rivers in Shenzhen city were screened from 7 species in a simulated urban river. In the investigation, the indexes such as covering rate, biomass, slope adaptability, root characteristics, submergence tolerance and erosion resistance of the grasses were compared. The results show that all the 7 species can grow in the embankments along the simulated urban river, and that there are significant differences in the above-mentioned indexes of the cuhivars after 4 months of cultivation. It is also demonstrated that P. notatum is a desirable species due to its highest covering rate （70%）, greatest biomass （8.33 kg/m^2 in dry weight） and root biomass （2.09kg/m^2） and the most effective roots with a diameter of less than 1 mm. Furthermore, P. notatum is of the best submergence tolerance and its half lethal time under partial and full drowned conditions is up to 45 d and 15 d, respectively. The block of P. notatum is also found to be resistant to an erosive velocity of 4. 0 m/s. By considering all the above-mentioned statements, it is thus concluded that P. notatum is the most suitable for the slope protection of urban rivers in Shenzhen city.