河道生态护坡工程中植被毯孔隙率对植物出苗过程的影响

The influence on seedling emergence by pore porosity of vegetation carpet during the projects of ecological slope protection of river channel

在河道护坡工地研究了7个孔隙率梯度(80%、70%、60%、50%、40%、30%、20%)的植被毯样品(椰丝、麦秸混合类型)对不同建植植物(黑麦草,高羊茅,无芒雀麦,苜蓿)幼苗出苗率和出苗时间的影响。结果表明,黑麦草、高羊茅、无芒雀麦的幼苗出苗率会随植被毯孔隙率的降低而缓慢下降,幼苗初始出苗时间变化不无显著。当植被毯孔隙率小于60%时,苜蓿的幼苗出苗率会快速下降;植被毯孔隙率小于20%时,苜蓿的幼苗出苗率降至10%以下,不适合植物建植。结合植被毯质量指标的研究结果,当植被毯的厚度、密度以及孔隙率分别为0.8~1.8cm、200~500g/m2、80%~60%时,植被毯上建植的各种植物有最大的幼苗出苗率。

Samples of vegetation carpet mixed by shredded coconut and straw have been researched on emergence rate of plant seedling and emerging time with seven porosity gradients,which are 80 percent,70 percent,60 percent,50 percent,40 percent,30 percent and 20 percent at work site of channel slope protection.The results show that plant seedling of ryegrass,tall fescue,smooth bromegrass,and alfalfa would be slowly decreased with lower pore porosity,while the change is not obvious for initial emerging time.As for alfalfa,when pore porosity is smaller than 60 percent,rate of plant seeding would be quickly decreased,and when pore porosity is smaller than 20 percent,rate of plant seeding would be decreased to less than 10 percent,then it would be not suitable for planting alfalfa.In view of the research on quality index of vegetation carpet,when the value of depth is from 0.8cm to 1.8cm,density from 200 to 500g/m 2,and pore porosity from 80 percent to 60 percent,the emergence rate of plant seedling would be maximum for different plants on vegetation carpet.