安徽省淮河流域湿地土壤养分流失及水质动态研究

Study on Soil Nutrient Loss and Water Quality Dynamics of Wetland in Huaihe River Basin of Anhui Province

以淮河流域(安徽段)湿地为研究区域,连续3a(2012—2014年)在野外调查和室内分析的基础上,采用定点实地调查、土壤和水质采样相结合的方法,研究了不同水期(平水期、丰水期和枯水期)淮河流域湿地土壤养分流失、水质动态及湿地植被多样性特征,并运用冗余分析(RDA)和偏相关分析手段揭示不同水期淮河流域湿地植被多样性与环境因子之间的关系。结果表明:(1)淮河流域湿地植被Shannon-Wiener多样性指数(H)、Pielou均匀度指数(J_P)、Margalef种类丰富度指数(d_(Ma))在丰水期达到最高,平水期和枯水期较低,基本表现为丰水期>枯水期>平水期,Simpson优势度指数(D)基本表现为平水期>枯水期>丰水期。(2)不同水期土壤pH、电导率、全盐和总孔隙度在0—40cm剖面上变化趋势基本一致,不同水期土壤pH随土层深度的增加而增加,电导率和全盐含量呈先降低后增加趋势,土壤总孔隙度呈降低趋势。(3)随着水期的变化,土壤DP、K^+、SEP和SEK呈增加趋势,在枯水期达到峰值,平水期最低,基本表现为枯水期>丰水期>平水期,土壤DP、K^+和SEK增加幅度逐渐增加,而土壤SEP增加幅度逐渐减小,以SEK含量波动较大。(4)水温、TN、TP、BOD5和CODCr呈一致的变化规律,随水期的变化呈先增加后降低趋势,透明度呈"V"字形变化规律,基本表现为平水期>枯水期>丰水期。(5)偏相关分析显示,不同水期淮河流域湿地植被多样性均与透明度呈极显著的负相关(P<0.01),透明度能够反映出淮河湿地植被多样性及水质状况,影响平水期和枯水期植被多样性主要因子为BOD5浓度和CODCr浓度,影响丰水期植被多样性主要因子为TN浓度和TP浓度。

On the basis of field investigation（field survey in fixed positions）, soil and water sampling and laboratory analysis in 3 consecutive years（2012--2014）, the water quality dynamics, soil nutrient loss and wetland plant diversity in average season, flood season and dry season in Huaihe River Basin were studied, and the relationships between wetland plant diversity and environmental factors（soil nutrient loss and water quality index） were analyzed by the method of redundancy analysis（RDA） and partial correlation analysis. The results showed that. （1）In Huaihe River Basin, there were seasonal variation in wetland plant diversity, with the Shannon-Wiener diversity index（H）, Pielou evenness index（Je） and Margalef richness index（dr, ） all listing in the order of flood season〉〈dry season〉average season, and the Simpson dominance index（D） following the sequence of average season〉dry season〉 flood season. （2） The soil pH, conductivity, total salt content and the total porosity showed similar changing trends in 0-40 cm soil layer across different water seasons. With the increase of soil depth, soil pH increased, soil conductivity and total salt content decreased at first and then increased, and the total soil porosity deceased. （3）The concentrations of DP, K＋, SEP and SEK in soil increased with the changing water seasons, which listed in the order of dry season〉flood season〉average season. The increase extents of DP, K＋ and SEK gradually increased, while that of SEP gradually decreased, and the concentration of SEK significantly fluctuated. （4）The water temperature, TN, TP, BODs and CODcr had the same variation trend, which increased at first and then decreased with the changing water seasons, while transparencyshowed a ＂V＂ trend, following the order of average season〉dry season〉flood season. （5）Partial correlation analysis showed that wetland plant diversity showed extremely significant negative correlation with transparency（P〈 0.01） across different water seasons, which suggested that the water transparency could reflect the wetland plant diversity and the water quality of wetland in Huaihe River Basin. The concentrations of BODs and CODcrwere the main influencing factors of wetland plant diversity in dry season and average season, while the concentrations of TN and TP were the main influencing factors in flood season.