摘要
为探究尕海湿地退化演替过程中土壤有机氮各组分变化规律,采用野外采样与室内分析相结合的方法,研究尕海湿地未退化(UD)、轻度退化(LD)、中度退化(MD)和重度退化(HD)4个退化演替阶段的土壤总氮(TN)和有机氮组分[未知态氮(HUN)、酸解氨态氮(AMN)、酸解氨基酸态氮(AAN)以及氨基糖态氮(ASN)]含量及其分布特征。结果表明:当尕海湿地退化演替到LD时,0~10 cm层土壤TN、HUN、AMN和AAN含量分别降低17.3%、19.4%、8.6%和-5.6%,MD时分别降低28.0%、19.4%和17.1%和0,HD时分别降低35.8%、28.8%、28.6%和55.6%;10~20 cm层,LD时上述氮素含量分别降低4.0%、10.3%、2.9%和9.1%;MD时分别降低21.0%、18.3%、-2.9%和-9.1%;HD时分别降低9.9%、38.9%、21.2%和51.4%;而20~40 cm无显著变化;4个退化阶段各酸解氮组分占TN比例大小顺序为HUN(25.9%~32.5%)> AMN(6.7%~11.1%)> AAN(4.8%~11.1%)> ASN(1.2%~4.4%)。冗余分析显示,土壤含水量是土壤有机氮组分变化的主要驱动因子。尕海湿地退化显著降低了0~10 cm层土壤TN及酸解氮各组分含量,减弱了土壤氮"汇"功能,AAN和ASN对湿地退化最为敏感。
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.
作者
唐艳梅
马维伟
李广
徐国荣
张悦
潘平新
宋良翠
龙永春
常文华
TANG Yan-mei;MA Wei-wei;LI Guang;XU Guo-rong;ZHANG Yue;PAN Ping-xin;SONG Liang-cui;LONG Yong-chun;CHANG Wen-hua(College of Fores-try,Gansu Agricultural University,Lanzhou 730070,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2021年第11期4077-4084,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(31860143)
2019陇原青年创新创业项目(LYRC2019-34)
甘肃农业大学科技创新基金项目(GAU-XKJS-2018-116)
甘肃省财政专项(GSCZZ-20160909)资助。
关键词
尕海
湿地退化
酸解氮组分
冗余分析
Gahai
wetland degradation
acidolytic nitrogen
redundancy analysis