丹江口库区马尾松人工林地表径流氮磷截留效应

Nitrogen and phosphorus interception effects in surface runoff of Pinus massoniana plantation in Danjiangkou reservoir area

滨水植被缓冲带能有效去除地表径流中的面源污染物。本文采用模拟地表径流的方式,探讨了丹江口库区坡度分别为11°、15°、17°和21°的4种马尾松人工林滨水植被缓冲带不同宽度条件下对径流污染物的截留效果及其影响因素。采用双环入渗试验测定土壤渗透性能,环刀法测土壤密度及最大持水量,同时测定了不同坡度下林下枯落物的厚度和生物量。结果表明:坡度、宽度、枯落物厚度和枯落物生物量是影响截留率的主要因素。4种坡度下,截留率均随宽度的增加而增加,随着坡度的增加而减小。当滨水植被缓冲带的坡度为11°时,4种面源污染物的截留率要达到80%,其宽度应为34 m左右;坡度为15°时,宽度为40 m左右;当坡度为17°时,宽度为45 m左右;当坡度为21°时,宽度为48 m左右。这些研究结果对库区马尾松人工林滨水植被缓冲带的营造和管理具有一定的参考价值。

Riparian vegetation buffer zone can effectively remove non-point source pollutants from surface runoff. We used the method of simulating surface runoff to investigate the interception effect on pollutants and the influencing factors of different width riparian vegetation buffer zone of four Pinus massoniana plantations with slopes of 11°,15°,17° and 21° in the Danjiangkou reservoir area. Soil permeability was measured by double ring infiltration test. Soil density and maximum water-holding capacity were measured by ring knife method. The thickness and biomass of litter under different slopes were measured. The results showed that slope,width,litter thickness and litter biomass were the main factors affecting the interception rate. Under the four slope conditions,the interception rate increased with the width and decreased with the slope. To obtain80% of interception rate of four non-point source pollutants,the width of buffer zone should be about 34 m when the slope of the riparian vegetation buffer zone was 11°,about 40 m for the slope of 15°,45 m for the slope of 17°,and 48 m for the slope was 21°. Our results provide reference for the construction and management of riparian vegetation buffer zone of Pinus massoniana plantations in the reservoir area.