Ying Yong Sheng Tai Xue Bao. 2021 Nov 15;32(11):4077-4084. doi: 10.13287/j.1001-9332.202111.035.
This study amined to explore the variation of soil organic nitrogen components across the degradation succession of Gahai Wetland. By combining field sampling and laboratory analysis, the content and distribution characteristics of soil organic nitrogen components, i.e., hydrolytic total nitrogen (HTN), unidentified acidolytic nitrogen (HUN), ammonium nitrogen (AMN), amino acid nitrogen (AAN) and acid amino sugar nitrogen (ASN) were investigated in undegraded (UD), lightly degraded (LD), moderately degraded (MD), and heavy degraded (HD) Gahai Wetland. The results showed that, in the 0-10 cm layer, the contents of total nitrogen (TN), HUN, AMN, and AAN in LD decreased by 17.3%, 19.4%, 8.6%, and -5.6%, 28.0%, 19.4%, 17.1% and 0 in MD, and 35.8%, 28.8%, 28.6% and 55.6% in HD, respectively. In the 10-20 cm layer, the four components decreased by 4.0%, 10.3%, 2.9% and 9.1% in LD, 21.0%, 18.3%, -2.9% and -9.1% in MD, and 9.9%, 38.9%, 21.2% and 51.4% in HD, respectively. The corresponding contents in the 20-40 cm soil layer did not change. The proportion of soil acid-hydrolyzed nitrogen components to TN under four degradation stages was HUN (25.9%-32.5%) > AMN (6.7%-11.1%) > AAN (4.8%-11.1%) > ASN (1.2%-4.4%). Soil water content was the main driving factor for variations of soil organic nitrogen components as indicated by the results of redundancy analysis. Degradation of the Gahai Wetland significantly reduced the content of soil TN and the components of acid-hydrolyzed nitrogen in 0-10 cm soil layer, and weakened the nitrogen "sink" function of soils. The AAN and ASN were sensitive to wetland degradation.
本研究旨在探讨高寒湿地退化演替过程中土壤有机氮组分的变化。通过野外采样和室内分析相结合的方法，研究了未退化（UD）、轻度退化（LD）、中度退化（MD）和重度退化（HD）高寒湿地土壤有机氮组分（水解总氮 HTN、未鉴定酸解氮 HUN、铵态氮 AMN、氨基酸氮 AAN 和酸性氨基糖氮 ASN）的含量和分布特征。结果表明，0-10cm 土层中，LD 处理下 TN、HUN、AMN 和 AAN 含量分别降低了 17.3%、19.4%、8.6%和-5.6%、28.0%、19.4%、17.1%和 0，MD 处理下分别降低了 35.8%、28.8%、28.6%和 55.6%，HD 处理下分别降低了 28.0%、19.4%、17.1%和 0。10-20cm 土层中，LD 处理下四个组分分别降低了 4.0%、10.3%、2.9%和 9.1%，MD 处理下分别降低了 21.0%、18.3%、-2.9%和-9.1%，HD 处理下分别降低了 9.9%、38.9%、21.2%和 51.4%。20-40cm 土层中各组分含量无明显变化。四个退化阶段土壤酸解态氮组分占 TN 的比例依次为 HUN（25.9%-32.5%）> AMN（6.7%-11.1%）> AAN（4.8%-11.1%）> ASN（1.2%-4.4%）。冗余分析结果表明，土壤含水量是土壤有机氮组分变化的主要驱动因素。高寒湿地退化显著降低了 0-10cm 土层土壤 TN 含量和酸解态氮组分含量，削弱了土壤氮素“汇”功能。AAN 和 ASN 对湿地退化较为敏感。
