湿地退化条件下土壤碳氮磷储量与生态化学计量变化特征

发布时间：2018-09-05 09:00

【摘要】：为了研究湿地退化过程中土壤碳氮磷储量与生态化学计量变化,明确碳氮"汇"功能的变化和土壤碳、氮、磷的平衡关系,采用实地采样调查、室内分析与数理统计法,研究了若尔盖自然湿地保护区内未退化湿地沼泽(MA)、沼泽化草甸(MM)、草甸(ME)3种不同退化程度湿地的典型样地在碳氮磷含量、储量以及生态化学计量的变化特征。结果表明,草甸化沼泽土与草甸土全剖面总有机碳、全氮含量较沼泽土分别降低了29.55%,6.52%和67.53%,40.04%,碳氮储量分别降低了67.49%,60.10%和85.14%,54.47%;3种土壤全磷剖面含量大小顺序为MMMEMA,其储量高低顺序是MEMAMM。随着土层深度的增加,沼泽土的总有机碳、全氮含量明显升高,全磷含量与草甸化沼泽土、草甸土的总有机碳、全氮、全磷含量均呈现降低趋势;3种土壤碳氮磷储量40—100cm土层高于0—40cm土层。沼泽土、草甸化沼泽土、草甸土3种不同类型土壤C/N分别为40.38,31.70,23.26,C/P分别为409.52,247.46,113.07,N/P分别为10.43,7.90,5.02,土壤C/N、C/P、N/P均随湿地退化而减小,较高的C/P与N/P14揭示氮磷元素均是影响植物生长的限制性因素,且受氮素限制高于磷素。因此,若尔盖湿地退化导致土壤碳氮含量与储量降低,碳氮"汇"功能减弱,尤其是碳"汇"。
[Abstract]:In order to study the changes of soil carbon, nitrogen and phosphorus reserves and ecological stoichiometry in the process of wetland degradation, and to clarify the relationship between carbon, nitrogen and phosphorus balance between carbon and nitrogen "sink" function and soil carbon, nitrogen and phosphorus balance, field sampling investigation, indoor analysis and mathematical statistics were used. The characteristics of carbon, nitrogen and phosphorus contents, reserves and ecological stoichiometry of three typical wetlands with different degree of degradation, (MA), marshland, (MM), meadow, (MM), meadow and (ME), were studied in Ruoergai Nature Wetland Reserve. The results show that the total organic carbon in the whole profile of meadow marsh soil and meadow soil is reduced 29.55% 6.52% and 67.53% and 40.04%, respectively, and the carbon and nitrogen reserves are reduced by 67.490.10% and 85.14% 54.47%, respectively. The order of total phosphorus content of the three soils is that the MMMEMA, reserves are in the order of MEMAMM.. With the increase of soil depth, total organic carbon and total nitrogen content of marsh soil increased obviously, total phosphorus content and total organic carbon, total nitrogen content of meadow soil, total organic carbon of meadow soil, total nitrogen, total phosphorus content, total organic carbon, total nitrogen content, The content of total phosphorus in 40-100cm soil layer was higher than that in 0-40cm soil layer. In marsh soil, meadow marsh soil and meadow soil, the C / N ratios of three different types of soils were 40.38 831.70 / 23.26 C / P = 409.52247.46113.07 N / P, respectively, and the C / N / P ratios of soil C / N / P / P decreased with wetland degradation, respectively. The higher C / P and N/P14 revealed that N and P elements were the limiting factors affecting plant growth. And the nitrogen limitation was higher than that of phosphorus. Therefore, the degradation of Zoige wetland leads to the decrease of soil carbon and nitrogen content and storage, and the weakening of carbon and nitrogen sink function, especially the carbon sink.
【作者单位】：四川农业大学资源学院;四川农业大学环境学院;
【基金】：国家自然科学基金项目(41401328) 四川省教育厅项目(14ZB0011)
【分类号】：S153.6

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