三江平原环型湿地土壤养分的空间分布规律

SOIL NUTRIENT DISTRIBUTION OF ANNULAR WETLANDS IN SANJIANG PLAIN

以三江平原环型湿地作为研究对象,对其环带状植被区湿地土壤的有机碳、全氮、全磷和全钾的空间分布规律进行了初步研究。结果表明,环型湿地土壤有机碳、全氮、全磷和全钾具有明显的空间水平分异规律,有机质、全氮、全磷的含量由环型湿地中心向边缘逐渐减少,全钾的含量和碳氮比逐渐增加。土壤有机碳、全氮、全磷和全钾在垂直方向上具有明显的分层和富聚现象,自上而下,有机质的含量逐渐降低;全氮含量除漂筏苔草群落外,其他各群落土壤全氮含量呈先增加后减少的分布;大部分植物群落全磷含量呈先减后增的“V”型分布;全钾含量呈表层和底层较高、中间层较低的“中空”状分布。通过相关分析表明,环型湿地土壤有机碳与全氮具有相似的空间分布规律,全钾与有机碳、全氮具有相异的空间分布规律,而全磷具有自己独特的空间分布规律。环型湿地土壤的有机碳、全氮、全磷和全钾的空间分布主要受植物体元素含量、生物过程和水文地貌过程影响,它通过过程影响湿地的功能。研究环型湿地的有机碳、全氮、全磷和全钾的空间分布规律不仅有助于完善湿地土壤形成和发育的理论,探明湿地的生态过程和功能,而且为合理利用和保护湿地提供科学依据。

Through field sampling and investigation, spatial distribution of soil organic carbon, total nitrogen, total phosphorus and total potassium in annular wetlands of the Sanjiang Plain was studied preliminarily. The results showed that horizontally it varied sharply, but followed a certain law, that is, soil organic matter, total nitrogen and total phosphorus gradually decreased in content, but total potassium content and C/N ratio gradually increased along the direction from center to edge of the wetlands. Vertically these soil chemical elements also varied, showing obvious stratification and enrichment. In a soil profile, organic matter declined in content with the depth; soil organic carbon under all the five vegetation communities gradually decreased; soil total nitrogen increased first and then decreased under all the vegetation communities except under Ass. Carex pseudocuraica; total phosphorus and total potassium under most vegetation communities decreased first and then increased. The results of correlation analysis between soil organic matter, total nitrogen, total phosphorus and total potassium suggest that soil organic carbon and total nitrogen showed a similar pattern in distribution; the spatial distribution pattern of total potassium was completely different from that of soil organic carbon and total nitrogen; and total phosphorus had its own unique pattern of distribution. The distribution law of soil organic carbon, total nitrogen, total phosphorus and total potassium of the wetlands was mainly impacted by element contents of the plants, biological processes and hydro-geomorphological processes. The study on the distribution laws of soil organic carbon, total nitrogen, total phosphorus and total potassium of the annular wetlands is not only helpful in perfecting the theory of wetland soil formation and development, and proving up ecological processes and function of wetlands, but also provides scientific basis for reasonable exploitation and protection of the wetland resources.