生态学报2025，Vol.45Issue(6)：2571-2581,11.DOI:10.20103/j.stxb.202408061858
模拟氮沉降对藏北高寒草原典型物种根系木质素降解的影响
Effects of simulated nitrogen deposition on lignin degradation in roots of typical species in alpine steppe on Northern Tibet
摘要
Abstract
Lignin is the most recalcitrant component in litter decomposition,and its degradation process serves as the rate-limiting step in the carbon cycle of terrestrial ecosystems.However,the effects of nitrogen deposition on lignin degradation rates in alpine steppe plant roots remain unclear.Utilizing a four-year nitrogen deposition simulation platform,we employed the litterbag method to examine the effects of nitrogen deposition on root litter decomposition and lignin degradation in four typical plant species of the northern Tibetan alpine steppe.The results showed that:(1)Simulated nitrogen deposition had no significant effects on the root mass loss rate or lignin degradation rate of plants in alpine steppe of northern Tibet.(2)The root litter mass loss rate progressively increased with decomposition time,while the lignin degradation rate exhibited a pattern of being initially low,increasing during the middle stage,and decreasing in the final stage of decomposition.(3)The root mass loss rate was regulated by the initial lignin/nitrogen ratio,with roots having a high initial lignin/nitrogen ratio showing significantly lower mass loss rates compared to those with lower ratios.The lignin degradation rate was regulated by the initial lignin concentration,with high-lignin roots exhibiting faster lignin degradation rates than low-lignin roots.These findings provide valuable insights into the effects of nitrogen deposition on root decomposition and material cycling in alpine grassland ecosystems.关键词
氮添加/凋落物分解袋法/凋落物质量/分解阶段Key words
nitrogen addition/litter bag method/litter quality/decomposition stage引用本文复制引用
李锦梅,洪江涛,庞博,王小丹..模拟氮沉降对藏北高寒草原典型物种根系木质素降解的影响[J].生态学报,2025,45(6):2571-2581,11.基金项目
第二次青藏高原科学考察研究(2019QZKK0404) （2019QZKK0404）
国家自然科学基金项目(42271070) （42271070）
