广州流溪河河岸缓冲带生态治理的优良草种筛选试验

Selection of proper herbaceous species for ecological modification to riparian buffer strips of Liuxi River, Guangzhou

广州流溪河新筑的河堤完全祼露,河流两边的河岸缓冲带受到人类活动的破坏而成为裸露的砂石地或杂草丛生,二者都需要进行生态整治。为了对河流两岸进行生态改造,形成一种护坡效果好、景观效果佳的新流域景观,作者在一段河堤与两块不同性质的河岸缓冲带上进行了适宜草种的筛选试验。在河堤被测试的5个草种中,假俭草的综合表现最好,其次是百喜草,再次是钝叶草与森特钝叶草,野花生的表现最差。在砂石基质的河岸缓冲带样地I,丛生性的大雀稗、弯叶画眉草和香根草表现较好,而匍匐性的野花生、钝叶草和百喜草表现较差,这主要是后三者因根系浅,易遭洪水冲击。至于种植在土质的河岸缓冲带样地II上的草种,由于土质状况好,淹水时间短,普遍表现良好。总的来看,弯叶画眉草、大雀稗在河岸缓冲带上的综合表现最好,但如果从耐淹角度来考虑,香根草也应是一个较理想的草种。

The newly-built embankments along the Liuxi River, Guangzhou were completely barren and, therefore, needed to be protected with appropriate eco-engineering measures. The riparian buffer strips of the river were destroyed, as a result it completely bare or covered by weeds. Therefore, it was in need of ecological modification with suitable herbaceous species. In order to effectively harness the riparian buffer strips of the river to form a new ecological landscape, a field experiment to screen appropriate species was carried out on a section of riverbank and two blocks of riparian buffer strips with different properties. Among the tried 5 herbaceous species on the riverbank, Eremochloa ophiuroides performed the best on the whole, followed by Paspalum notatum, Stenotaphrum helferi and Stenotaphrum secundatum, and Arachis pintoi the poorest. Later, the growth of all the 5 species, however, became poorer and poorer due to the excessively high temperature, less rainfall, and infertile and solid soil during the period July and August. On the rocky riparian buffer strips plot I, the tufty species, Paspalum giganteum, Eragrostis curvula, and Vetiveria zizanioides assumed better performance, but the prostrate A. pintoi, S. helferi, and P. notatum assumed poorer performance due to shorter roots and therefore prone to be washed away by flood. Regarding those plant species grown on the terrene riparian buffer strips plot II, they all grew good due to better soil fertility, and less submergence and flood. All in all, E. curvula, and P. giganteum had the best comprehensive performance on the riparian buffer strips, and V. zizanioides was also worth planting if considering it from the angle of submergence tolerance.