摘要
气候变化引起的土壤碳源和氮源输入变化对森林生态系统碳、氮动态有潜在的重要影响.了解不同团聚体和化学成分的碳、氮组分对碳源和氮源输入的响应,对进一步揭示和预测未来气候变化下土壤碳、氮的响应特征具有重要意义.为了探究土壤不同碳、氮组分及其计量比对土壤碳源和氮源输入变化的响应特征,本研究基于在温带油松-辽东栎混交林样地建立的长期(8年)地上凋落物处理和氮添加实验,测定和分析了土壤不同团聚体碳、氮组分、可溶性碳、氮组分和微生物生物量碳、氮等指标.结果表明:长期叶凋落物加倍和混合凋落物加倍(含枝、叶和球果)均显著增加了土壤总有机碳、全氮、可溶性碳、活性碳及大团聚体(250~2000μm)和微团聚体(53~250μm)碳、氮组分的含量;氮添加显著增加了土壤总有机碳、全氮、可溶性氮及活性碳组分的相对和绝对含量;但土壤黏粉粒(2~53μm和<2μm)碳、氮组分、微生物生物量碳、氮及各碳、氮组分比值在不同处理之间均无显著性差异;地上叶凋落物加倍和混合凋落物加倍处理显著增强了土壤团聚体的稳定性并降低了土壤可溶性有机质的芳香性.这些结果表明,高质量和数量凋落物的输入及氮添加量的增加显著促进了土壤不同碳、氮组分的含量,但并没有显著改变各碳、氮组分的比值.
Climate change⁃induced changes in soil carbon and nitrogen inputs potentially have important effects on carbon and nitrogen dynamics in forest ecosystems.Understanding the responses to carbon and nitrogen inputs in carbon and nitrogen fractions of varying aggregates and chemical compositions is of great significance for further uncovering and predicting the patterns of responses in soil carbon and nitrogen under future climate change.To determine the responses of different soil carbon and nitrogen fractions and their ratios to changes in soil carbon and nitrogen input sources,this study used an established long⁃term(8 years)aboveground litter treatment and nitrogen addition experiment in a temperate Pinus tubuliformis⁃Quercus wutaishansea forest in northern China,and measured carbon and nitrogen fractions in different soil aggregates,dissolved organic carbon(DOC)and nitrogen(DON),and microbial biomass carbon and nitrogen,etc.Results show that the long⁃term treatments of doubling leaf litter and mixed litter(containing twigs,leaves and pine cones)significantly increased the total organic carbon(TOC)and nitrogen(TN),DOC,labile organic carbon(LOC),and the organic carbon and nitrogen fractions in macroaggregates(250~2000μm)and microaggregates(53~250μm),and that nitrogen addition significantly increased soil TOC,TN,DON,and relative and absolute contents of LOC;whereas there were no significant differences among treatments in carbon and nitrogen fractions in clay and silt aggregates(2~53μm and<2μm),microbial biomass carbon and nitrogen,and various ratios of carbon and nitrogen fractions.Treatments of doubling aboveground leaf litter and mixed litter significantly enhanced the stability of soil aggregates and reduced the aromatization of soil dissolved organic matter.These results indicate that the inputs of high quality and quantity of aboveground litter and nitrogen addition significantly increased the content of different soil carbon and nitrogen fractions,but not the ratios of various carbon and nitrogen fractions.
作者
郭晓伟
张雨雪
张潇
周岱瑒
孙建新
GUO Xiaowei;ZHANG Yuxue;ZHANG Xiao;ZHOU Daiyang;SUN Jianxin(College of Ecology and Nature Conservation,Beijing Forestry University,Beijing 100083;College of Forest Science,Beijing Forestry University,Beijing 100083)
出处
《环境科学学报》
CAS
CSCD
北大核心
2020年第7期2589-2598,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.31870426,31470623)
国家级大学生创新创业训练项目(No.201810022005,201810022006)。
关键词
土壤碳、氮组分
团聚体稳定性
凋落物质量
氮添加
温带森林
soil carbon and nitrogen fractions
aggregate stability
litter quality
nitrogen addition
temperature forest
