武夷山人工湿地系统植物生长期内土壤-植物碳氮磷变化特点

Characteristics of soil and plant carbon,nitrogen,and phosphorus during plant growth in the Wuyi Mountain constructed wetland system

通过对世界自然与文化双遗产地武夷山市生活污水处理厂人工湿地植物生长期内植物和土壤C、N、P化学计量的研究,旨在阐明世界双遗产地武夷山人工湿地系统植物生长期内植被的养分循环及限制状况,为维持世界双遗产地武夷山内人工湿地生态系统的稳定提供借鉴.在一个生长季内分4次(7、14、21、28周)测定武夷山市生活污水处理厂人工湿地系统主要植物再力花(Thalia dealbata)、花叶芦荻(Arundo donax var. versicolor)、香根草(Vetiveria zizanioides L.)和土壤的C、N、P含量变化,分析化学计量特征及其相关性.结果表明:(1)一个生长季内,人工湿地系统土壤C、N、P含量均呈先降低后增加的趋势,其变化范围分别为14.39-18.32、0.72-6.11、0.47-0.73 mg/kg;(2)再力花、花叶芦荻叶、茎C含量随着植物的生长呈上升趋势,香根草C含量呈先增后减趋势,再力花、花叶芦荻叶的N含量呈上升趋势,茎N含量呈先减后增趋势,香根草N含量呈下降趋势,再力花、花叶芦荻叶P含量呈先增后减趋势,再力花和花叶芦荻的茎和香根草P含量呈下降趋势,其变化范围分别为402.56-527.13、6.16-22.06、1.54-3.02 mg/kg;(3)再力花和花叶芦荻的叶C:N、C:P、N:P与土壤C:N、C:P、N:P无显著相关,但叶N含量与土壤N含量存在显著负相关.香根草C:N、C:P与土壤C:N、C:P存在正相关,香根草C含量与土壤中C含量存在负相关,香根草N含量与土壤N含量存在正相关.综上所述,在一个生长季内,3种植物的C、N、P含量、化学计量比及其变化趋势存在差异;土壤N含量影响着再力花和花叶芦荻叶N含量,香根草同时受土壤C、N含量的影响;本研究结果可为世界双遗产地武夷山人工湿地营造策略、环境保护以及植物配置提供参考.(图2表4参55)

This study evaluated the characteristics of soil and plant carbon,nitrogen,and phosphorus during plant growth in the Wuyi Mountain Municipal Domestic Wastewater Treatment Plant,a natural and cultural world heritage site.The purpose of this study was to elucidate nutrient cycling and the restriction of the vegetation in the constructed wetland system of the natural and cultural world heritage site in order to ensure that management effots maintain this site within the established standards.The main plants of the constructed wetland system were Thalia dealbata,Arundo donax var.versicolor,and Vetiveria zizanioides L.Soil carbon,nitrogen,and phosphorus changes in four periods(7,14,21,and 28 weeks)were evaluated to analyze their stoichiometric characteristics and potential correlations.The results showed that the content of carbon,nitrogen,and phosphorus in the constructed wetland system decreased first and then increased,and the ranges of variation were 14.39-18.32 mg/kg(C),0.72-6.11 mg/kg(N),and 0.47-0.73 mg/kg(P)during the growing season.The C content in the leaves and stems of T.dealbata and A.donax var.versicolor increased with the growth of plants,while that of V.zizanioides L.C increased first and then decreased.The N content in the leaves of T.dealbata and A.donax var.versicolor increased,while the N content in their stems decreased first and then increased.Vetiveria zizanioides L.N content showed a downward trend.Thalia dealbata and A.donax var.versicolor P content increased first and then decreased.The P content in the stems of T.dealbata,A.donax var.versicolor,and V.zizanioides L.showed a downward trend.The C,N,and P plant content ranges of variation were 402.56-527.13(C),6.16-22.06(N),and 1.54-3.02 mg/kg(P)during the growing season.There were no significant differences between the C:N,C:P,and N:P ratios in the leaves of T.dealbata and A.donax var.versicolor and those of the soil,but the N content in the leaves and the soil were significantly and negatively correlated.Vetiveria zizanioides L.was positively correlated with soil C:N and C:P ratios,and its C content was negatively correlated with soil C,but N content was positiviely.The dynamic analysis of the characteristics of soil and plant C,N and P content,stoichiometry,and their trends during plant growth in the Wuyi Mountain constructed wetland system showed differences between the three plants.The N content of the leaves of T.dealbata and A.donax var.versicolor was affected by soil N,and V.zizanioides L.was also affected by the content of C and N in the soil.These results provide a reference for the construction of management,environmental protection,and plant configuration strategies of the Wuyi Mountain constructed wetland in the natural and cultural world heritage site.