Liu Yun, Willison J H Martin, Wan Pan, Xiong Xing-Zheng, Ou Yang, Huang Xiao-Hui, Wu Jingchun, Zhou Hao, Xu Qiao, Chen Guohui, Xili Yuanzi, Nie Jiasheng
Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, China, 400716.
School for Resource and Environmental Studies, Dalhousie University, Halifax, NS, Canada, B3R 2C6.
Environ Sci Pollut Res Int. 2016 Mar;23(6):5288-95. doi: 10.1007/s11356-015-5731-9. Epub 2015 Nov 13.
China's Sloping Land Conversion Program (SLCP) was designed to restore perennial plant cover on sloping land in western China, in part to protect the Three Gorges Reservoir (TGR). In this study, we examined use of white mulberry (Morus alba L.) in the SLCP to protect water quality and conserve soil. We established nine runoff monitoring plots divided among three categories (vegetable farming, fallow control, and mulberry plantation) on a bank of the Liangtan River situated at the western margin of the TGR. The land had been used previously by farmers for growing vegetables. We found that soil loss and surface water runoff were lowest in the mulberry plots and highest in the vegetable plots. We used inductively coupled plasma atomic emission spectroscopy (ICP-AES) to assess the concentration of selected heavy metal pollution indicators (Zn, Hg, As, Ni, Pb, Cr, Cd, and Cu) in the monitoring plot soils at the beginning of the experiment in May 2009. The heavy metals were assessed again at the end of the experiment in October 2012, and we found that the concentrations of these pollutants had been reduced in all fallow and mulberry plots, and to the greatest extent in the mulberry plots. We found that levels of Hg, Pb, and Cu increased in the vegetable plots. For these reasons, we conclude that riparian mulberry plantations are useful for reducing rapid runoff of storm water, conserving soil, and sequestering heavy metal pollutants in the TGR region.
中国的坡耕地退耕还林工程（SLCP）旨在恢复中国西部坡耕地的多年生植被覆盖，部分目的是保护三峡水库（TGR）。在本研究中，我们考察了在坡耕地退耕还林工程中使用白桑（Morus alba L.）来保护水质和保持土壤。我们在位于三峡水库西缘的梁滩河岸上建立了9个径流监测小区，分为三类（蔬菜种植、休耕对照和桑园）。这片土地之前被农民用来种植蔬菜。我们发现，土壤流失和地表径流在桑园小区中最低，在蔬菜小区中最高。我们使用电感耦合等离子体原子发射光谱法（ICP - AES）在2009年5月实验开始时评估了监测小区土壤中选定的重金属污染指标（锌、汞、砷、镍、铅、铬、镉和铜）的浓度。在2012年10月实验结束时再次评估这些重金属，我们发现所有休耕和桑园小区中这些污染物的浓度都有所降低，在桑园小区中降低幅度最大。我们发现蔬菜小区中汞、铅和铜的含量增加。基于这些原因，我们得出结论，河岸桑园对于减少暴雨径流、保持土壤以及在三峡水库地区隔离重金属污染物是有用的。
