漓江水陆交错带4种草本覆盖对地表径流氮素的消减作用  

Effects of Four Herbaceous Plants Coverage on Reducing Surface Runoff Nitrogen in Lijiang River Aquatic-Terrestrial Ecotone

作　　者：吴林川 王冬梅[1] 任远[1] 张丹丹[1] 黄端[1] Wu Linchuan;Wang Dongmei;Ren Yuan;Zhang DANDan;Huang Duan(School of Soil and Water Conservation,Beijing Forestry University Beijing 100083;Shaanxi Provincial Land Engineering Construction Group Co. , Ltd. Xi＇ an 710075)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]陕西省土地工程建设集团有限责任公司,西安710075

出　　处：《林业科学》2018年第5期168-176,共9页Scientia Silvae Sinicae

基　　金："十二五"国家科技支撑计划项目(2012BAC16B03)

摘　　要：【目的】研究漓江水陆交错带不同草本植物覆盖对地表径流和泥沙中氮素的消减作用,以期筛选出防治水体富营养化的最佳草本植物,为水陆交错带生态修复提供理论依据。【方法】在漓江水陆交错带建立径流小区,设置狗牙根、狗尾草、假俭草和空心莲子4种草本覆盖区及无植被覆盖裸露区作为对照,研究4种草本植物覆盖对地表径流和泥沙及径流水、泥沙和土壤中不同形态氮素的消减作用。【结果】相较于裸地,狗牙根、狗尾草、假俭草和空心莲子草对径流的消减率分别为17%,35%,29%和23%,对径流中全氮的消减率分别为37%,43%,40%和52%;相较于裸地,狗牙根、狗尾草、假俭草和空心莲子草对侵蚀泥沙的消减率分别为17%,32%,26%和20%,对泥沙中全氮的消减率分别为31%,48%,41%和40%;径流消减率与NO3--N、TN消减率极显著正相关(P<0.01),与NH4+-N消减率显著正相关(P<0.05),降雨强度与NO3--N消减率显著负相关(P<0.05),与TN消减率极显著负相关(P<0.01)。【结论】4种草本植物覆盖对均能有效降低地表径流中氮素对水体的输入,狗尾草和空心莲子草的效果最好;氮素消减率与径流消减率显著正相关,因此拦截地表径流是防治水体污染的首要措施。【Objective】 To select the best herbaceous plants for preventing eutrophication,the effects of grass cover on runoff and sediment nitrogen（ N） reduction rate were explored in Lijiang River,an aquatic-terrestrial ecotone. This provides a theoretical basis for ecological restoration.【Method】Runoff and sediment processes on four types of grass cover（ Cynodon dactylon, Setaria viridis, Eremochloa ophiuroides and Alternanthera philoxeroides） were conducted in comparison to bare slope. Simultaneously,various forms of N were tested in runoff and sediment. Reduction rates of grass cover on runoff,sediment,N were calculated. 【Result 】 Compared to bare slope,Cynodon dactylon,Setaria viridis,Eremochloa ophiuroides and Alternanthera philoxeroides reduced runoff by 17%,35%,29%,and 23%,respectively.They reduced total N in runoff by 37%,43%,40%,and 52%（ P 〈 0. 05）. Compared to bare slope,Cynodon dactylon,Setaria viridis,Eremochloa ophiuroides and Alternanthera philoxeroides reduced sediment yield by 17%,32%,26%,and20%. They reduced TN in sediment by 31%,48%,41%,and 40%（ P 〈 0. 05）. Runoff reduction rate had significant positive correlation with reduction rates of NH4^＋-N and TN,and was correlated closely with NH4^＋-N reduction rate.However,rainfall intensity had significant negative correlation with reduction rates of NO3^--N and TN. 【Conclusion】Four types of grass cover all decreased the input of N to runoff. Setaria viridis and Alternanthera Philoxeroides had better function in reducing N loss with runoff. Positive relationship between N reduction rate and runoff reduction rate was established,therefore,conserve runoff loss from slope was an effective measure to prevent water pollution.

关 键 词：氮 径流 非点源污染 水陆交错带 削减作用 生态修复 漓江 

分 类 号：S719[农业科学—林学] X143[环境科学与工程—环境科学]