升金湖消落带植被特征及与土壤特性的关系

探讨湖泊湿地土壤特性对植物多样性的影响,对于理解湿地植被分布及功能的维持机制具有重要意义.在安徽升金湖消落带沿水位梯度设立研究样方,测定植物的盖度、地上生物量以及土壤含水量、有机碳、全氮、全磷等指标,并结合Pearson相关性分析、冗余分析(redundancy analysis,RDA)探讨了土壤特性对植物多样性的影响.结果表明,随着地下水位上升,土壤含水量与全氮含量显著增加(P<0.05),土壤有机碳和土壤全磷含量显著降低(P<0.05).土壤有机碳、全磷含量以及C?N与土壤含水量极显著负相关(P<0.001),土壤全氮、N?P以及C?P与土壤含水量极显著正相关(P<0.001).土壤含水量、土壤全氮含量以及C?P和N?P是影响消落带植被物种多样性变化的关键因子,共同解释了变化的91.85％.总之,土壤含水量可以直接影响消落带植物多样性,也可以通过改变土壤中氮元素的转化和磷元素的有效性间接影响物种多样性.

The correlations between vegetation composition and soil characteristics in the riparian zone of Shengjin Lake

Exploring the effects of soil characteristics of lake wetlands on plant diversity is of great significance to understand how wetland vegetation distributes and maintains its function. We established sampling plots along a series of groundwater level gradients in the riparian zone of Shengjin Lake in the Anhui Province and measured the coverage, aboveground biomass of plants and soil moisture, soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) among other indicators. By using Pearson correlation analysis and redundancy analysis (RDA), we examined the effects of soil characteristics on plant community diversity. The results showed that as the groundwater level increased, the soil moisture and TN content increased significantly, whereas soil SOC and TP content decreased significantly. The contents of SOC, TP, and C ? N were significantly and negatively correlated with soil moisture, whereas TN, N ? P, and C ? P were significantly and positively correlated with soil moisture. Collectively, soil moisture, TN content, C ? P, and N ? P were determined to be the key factors affecting plant diversity in the riparian zone, explaining 91.85% of the variation in plant diversity altogether. In conclusion, soil moisture could effectively determine plant community assemblage in the Shengjin Lake riparian zone, either directly or indirectly, by changing the cycling of N and the availability of P in the soil.