周期性水位波动对三峡水库消落带土壤有机碳含量和密度的影响

Effects of Periodic Water-level Fluctuations on Soil Organic Carbon Content and Density in Riparian Zone of Three Gorges Reservoir

为探究水位波动对三峡水库消落带土壤有机碳的影响,在三峡水库消落带采集和测定了受不同水淹强度影响的石灰土、紫色土、黄壤及其植物样品,并运用Kruskal-Wallis非参数检验和基于冗余分析的典范分析等方法进行了研究。结果表明:周期性水淹增加了石灰土和紫色土的有机碳含量和密度,但降低了黄壤的有机碳含量和密度。此外,石灰土的有机碳分布还受地上生物量、土壤pH和土层深度的影响,紫色土的有机碳分布还受土层深度和地上生物量的影响,而黄壤的有机碳含量和密度则与地上生物量、土层深度和地下生物量有关。总之,周期性水位波动对消落带土壤有机碳影响深刻,但土壤类型分异了有机碳对水位波动的响应。

In order to explore the effect of water level fluctuation on soil organic carbon in the hydro-fluctuation belt of the Three Gorges Reservoir,lime soil,purple soil and yellow soil samples and their plant samples affected by different flooding intensities were collected and tested,and Kruskal-Wallis non-parametric test and canonical analysis based on redundancy analysis were used for investigation.The results showed that periodic flooding increased the organic carbon contents and densities of calcareous soil and purple soil,but decreased the organic carbon content and density of yellow soil.In addition,the distribution of organic carbon in calcareous soil was also affected by aboveground biomass,soil pH and soil depth.The organic carbon in purple soil was also affected by soil depth and aboveground biomass,while the organic carbon content and density in yellow soil were related to aboveground biomass,soil depth and underground biomass.In short,periodic water level fluctuations have a profound impact on soil organic carbon in the hydro-fluctuation belt,but soil types differentiate the response of organic carbon to water level fluctuations.