长期氮磷添加对滨海湿地土壤微生物残体碳和酶活性的影响  

Effects of Long-term Nitrogen and Phosphorus Supply on Soil Microbial Necromass Carbon and Enzyme Activities in a Coastal Wetland

作　　者：杨丽娟 孙凯[1] 程蕊 杨小立 王大郅 李红丽[1] 王光美[2] YANG Li-juan;SUN Kai;CHENG Rui;YANG Xiao-li;WANG Da-zhi;LI Hong-li;WANG Guang-mei(School of Ecology and Nature Conservation,Beijing Forestry University,Beijing 100083,China;Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264000,China)

机构地区：[1]北京林业大学生态与自然保护学院,北京100083 [2]中国科学院烟台海岸带研究所,山东烟台264000

出　　处：《生态与农村环境学报》2024年第12期1624-1633,共10页Journal of Ecology and Rural Environment

基　　金：北京林业大学中央高校基本科研业务专项资金项目(QNTD202304);国家重点研发计划(2021YFC2600405);国家林业和草原局应急揭榜挂帅项目(202302)。

摘　　要：滨海湿地土壤氮磷水平及比例的变化影响了滨海湿地生态系统的结构和功能。目前长期氮磷添加对滨海湿地土壤微生物群落的影响已有一定的研究,但其对滨海湿地生态系统碳循环中土壤微生物残体碳和酶活性的影响机制尚不清楚。因此,基于黄河三角洲滨海湿地为期7 a(2014—2021年)的氮磷添加野外原位实验(包括低、中、高3种氮磷供应水平,每种氮磷供应水平设置5∶1、15∶1、45∶1这3种氮磷供应比例),探究了氮磷供应水平及比例对土壤微生物残体碳、酶活性及土壤有机碳(SOC)、速效氮、速效磷等含量及其之间相互关系的影响。结果表明,氮磷供应水平及比例对土壤微生物总残体碳、细菌残体碳、真菌残体碳及其与SOC的比值,SOC、速效氮、速效磷含量,土壤β-1,4-N-乙酰氨基葡萄糖苷酶、亮氨酸氨基肽酶和碱性磷酸酶活性均无显著影响。氮磷供应水平及比例仅显著影响β-1,4-葡萄糖苷酶含量,氮磷供应比例为15∶1时的高氮磷供应水平处理较对照降低约40%。在不同氮磷供应比例及水平添加条件下,土壤微生物残体碳、酶活性及土壤碳氮磷含量之间存在显著相关性。该研究强调了土壤微生物残体碳和酶活性在维持滨海湿地有机碳储量方面的重要性,研究结果对提升滨海湿地土壤有机碳变化的预测能力具有重要意义。The variation in nitrogen and phosphorus levels in coastal wetland soils affects the structure and function of coastal wetland ecosystems.While some studies have explored the effects of long-term nitrogen and phosphorus addition on soil microbial communities in coastal wetlands,the mechanisms by which these additions influence soil microbial necromass carbon and enzyme activities in the context of the carbon cycle remain unclear.Our study is based on a seven-year(2014-2021)in situ nitrogen and phosphorus addition field experiment in the Yellow River Delta coastal wetlands.The experiment included three nitrogen and phosphorus supply levels(low,medium and high),with three nitrogen-to-phosphorus ratios(5∶1,15∶1 and 45∶1,ratios,hereafter)for each supply level.The effects of nitrogen and phosphorus supply levels and ratios on soil microbial necromass carbon,enzyme activities,soil organic carbon(SOC),available nitrogen,available phosphorus and their interrelationships were investigated.The results show that nitrogen and phosphorus supply levels and ratios had no significant impact on total microbial necromass carbon,bacterial necromass carbon,fungal necromass carbon,their ratios to SOC,SOC content,available nitrogen,available phosphorus,or the activities of soilβ-1,4-N-acetylglucosaminidase,leucine aminopeptidase,and alkaline phosphatase.However,nitrogen and phosphorus supply levels and ratios significantly affectedβ-1,4-glucosidase content in soil,with high nitrogen and phosphorus supply levels under the 15∶1 ratio reducing activity by approximately 40%compared to the control.Significant correlations were observed between soil microbial necromass carbon,enzyme activities and soil carbon,nitrogen and phosphorus contents under different nitrogen and phosphorus supply levels and ratios.This study highlights the importance of soil microbial residue carbon and enzyme activities in maintaining SOC stocks in coastal wetlands,providing valuable insights for predicting changes in SOC in these ecosystems.

关 键 词：滨海湿地 氮磷添加 土壤微生物残体碳 酶活性 碳氮磷含量 

分 类 号：S154.2[农业科学—土壤学]