互花米草入侵对胶州湾河口湿地土壤总铁分布的影响

互花米草是胶州湾滨海湿地典型的入侵物种,为进一步了解互花米草入侵对胶州湾河口湿地土壤总铁含量分布的影响,于2017年3月、5月、7月、9月和11月分别在互花米草湿地和光滩采集土壤样品,并对土壤总铁含量、有机质含量、土壤可溶性盐、pH、含水率、容重和土壤粒度进行测定与分析。结果表明:互花米草入侵显著提高了土壤总铁含量,两样区0—50 cm土层土壤总铁含量差异显著(P0.05),5月和7月互花米草湿地总铁含量在垂直方向上呈先上升后下降趋势;与光滩在同一采样月份相比,互花米草湿地土壤总铁含量增幅分别为25.36%、29.50%、17.52%、30.28%和14.48%。相关性分析表明,互花米草湿地和光滩土壤总铁含量均与有机质含量和可溶性盐呈显著正相关(P0.01);并且光滩土壤总铁含量与含水率呈显著正相关(P0.01),与容重呈显著负相关(P0.01),表明两样区土壤总铁含量受有机质含量和可溶性盐影响较大。

Effects of Spartina alterniflora invasion on soil total iron distribution in estuary wetland of Jiaozhou Bay

Spartina alterniflora is a typical invasive species in Jiaozhou Bay coastal wetland. The effects of Spartina alterniflora invasion on soil total iron content variations in estuary wetland of Jiaozhou Bay were studied. Soil samples were collected from Spartina alterniflora wetland and mudflat in March, May, July, September, and November 2017. The contents of total iron, organic matter, soluble salt, pH, water content, bulk density, and particle size in soil were measured and analyzed. The results showed that Spartina alterniflora invasion significantly increased total iron contents in soil, and the differences were significant (P < 0.05) in the 0-50 cm soil layers of the two sampling regions. The total iron contents of Spartina alterniflora wetland increased first and then decreased in the vertical direction in May and July. Compared with the mudflat in the same sampling month, the total iron contents of Spartina alterniflora wetland increased by 25.36%, 29.50%, 17.52%, 30.28%, and 14.48%, respectively. The correlation analysis showed that the total iron contents in the soil of Spartina alterniflora wetland and mudflat were positively correlated with the contents of organic matter and soluble salt (P < 0.01). The total iron content in mudflat was positively correlated with water content (P < 0.01), and negatively correlated with bulk density (P < 0.01), which indicated the total iron contents in the two sampling regions were greatly affected by organic matter and soluble salt.