退耕还林措施对滇中尖山河坡地氮磷流失的削减效应  

Reduction Effect of Returning Farmland to Forest on the Losses of Nitrogen and Phosphorus on the Slope of the Jianshan River in Central Yunnan

作　　者：苏孟白 王克勤[1] 宋娅丽[1] 洪利达 SU Mengbai;WANG Keqin;SONG Yali;HONG Lida(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,China;Water Conservancy Bureau of Chengjiang,Chengjiang,Yunnan 652500,China)

机构地区：[1]西南林业大学生态与环境学院,昆明650224 [2]云南省澄江市水利局,云南澄江652500

出　　处：《水土保持研究》2023年第3期154-162,共9页Research of Soil and Water Conservation

基　　金：云南省科技计划项目(202203AC100001-03);云南省科技计划重点研发项目(2018BB018);云南省大学生创新创业训练计划项目(202010677047);云南省水土保持监测站网玉溪尖山河小流域水土保持监测站点。

摘　　要：[目的]探究滇中尖山河流域退耕还林措施下不同地类侵蚀性降雨、氮磷流失浓度、流失量的动态变化特征,对评价退耕还林生态工程对流域水体保护和面源污染的削减效应具有重要的指导意义。[方法]选择抚仙湖湖区典型流域尖山河小流域为研究区,以流域内退耕还林/坡耕地、人工林、灌木林和次生林为研究对象,对流域不同土地利用类型径流小区进行连续三年(2017-2019年)雨季(5-10月)定量监测。[结果]退耕还林后年侵蚀性降水量和年径流量分别降低37.16%和42.75%,产流量降低95.88%和94.29%。各态氮磷输出浓度分别削减:总氮34.32%、硝态氮32%、铵态氮61%、总磷73.4%和磷酸盐70.4%;各态氮磷输出量分别减少了总氮70.40 mg/m^(2),硝态氮41.24 mg/m2,铵态氮20.56 mg/m^(2),总磷162.16 mg/m^(2)和磷酸盐107.38 mg/m^(2),削减率分别为:79.29%,80.48%,88.20%,95.66%和97.06%。未退耕还林前坡耕地总氮、硝态氮、铵态氮、总磷和磷酸盐年均输出浓度分别为其他地类的156.80%,149.57%,173.15%,157.42%和153.82%,退耕还林后分别降至139.00%,117.66%,108.08%,123.18%和92.29%,虽仍高于流域其他地类,但削减和控制效应已逐年增加。[结论]在滇中尖山河流域进行退耕还林植被恢复,有效改善了流域面源污染和水土流失现状,为临湖流域水环境治理提供了科学依据和数据支持。[Objective]It is of great guiding significance for evaluating the reduction effect of the ecological project of returning farmland to forests on the protection of water environment and non-point source pollution in the river watershed to explore the dynamic change characteristics of erosive rainfall,nitrogen and phosphorus loss concentrations and loss amounts of different land types under the measures of returning farmland to forests in the Jianshan River watershed of central Yunnan Province.[Methods]Jianshan River watershed,a typical watershed in Fuxian Lake area,was selected as the study area.The main research objects were returning farmland to forest/sloping farmland,artificial forest,shrub forest and secondary forest in the watershed.Through quantitative monitoring in the different land use type runoff area in rainy season(May-October)for three consecutive years(2017-2019),the concentration,amount and dynamic characteristics of erosive rainfall,nitrogen and phosphorus losses were studied.[Results]The annual erosive precipitation and annual runoff after returning farmland to forests decreased by 37.16%and 42.75%,respectively.Runoff decreased by 95.88%and 94.29%,respectively.The export concentrations of of total nitrogen,nitrate,ammonium nitrogen,total phosphorus,and phosphate reduced by 34.32%,32%,61%,73.4%and 70.4%,respectively.The non-point source pollutantoutputs of for TN,NO_(3)^(-)N,NH_(4)^(+)-N,TP and PO^(3-)_(4)-P decreased 70.40 mg/m^(2),41.24 mg/m^(2),20.56 mg/m 2,162.16 mg/m^(2),and 107.38 mg/m 2,respectively.The reduction rates were 79.29%,80.48%,88.20%,95.66%and 97.06%,respectively.The output concentrations of TN,NO-3-N,NH+4-N,TP and PO^(3-)_(4)-P of slope farmland before conversion were 156.80%,149.57%,173.15%,157.42%and 153.82%of those of other land use types,respectively.After two years,they were 139.00%,117.66%,108.08%,123.18%and 92.29%respectively,which were still higher than those of other land use types in the watershed,but the reduction and control effects on nitrogen and phosphorus had inc

关 键 词：氮磷削减 退耕还林 尖山河流域 

分 类 号：S157.1[农业科学—土壤学]