摘要
激发效应(PE)在调控陆地土壤碳(C)循环中发挥着重要作用,但在氮(N)沉降日益严重的亚热带森林生态系统中,不同C添加模式对PE的影响尚不清楚。本研究通过添加^(13)C标记的葡萄糖,进行90 d的室内培养试验,探究不同施N水平下(0、20、80 kg N·hm^(-2)·a^(-1))C添加模式(单次C添加、重复C添加)对土壤PE的影响。结果表明:不同模式葡萄糖添加均显著增加了土壤有机C(SOC)矿化,产生了正PE,且单次的葡萄糖添加比重复添加引起的PE更大;随着施N水平的增加,PE显著减弱,表明N沉降抑制了毛竹林土壤激发。相关分析显示,累积PE与β-N-乙酰氨基葡萄糖苷酶(NAG)、过氧化物酶(PEO)活性呈显著负相关,与微生物生物量磷(MBP)、酸碱度(pH)呈显著正相关。综上,施N和C添加共同作用于土壤时,可以通过刺激亚热带森林中原生土壤有机质矿化而对土壤C储量产生强烈影响。本研究证明,单次C添加模式可能高估了外源易分解有机C对PE的影响,而忽略了N沉降对PE的影响,进而高估了森林SOC的矿化损失。
Priming effect(PE)plays an important role in regulating terrestrial soil carbon(C)cycling,but the impact of different C addition modes on the PE in subtropical forest ecosystems with increasing nitrogen(N)depo-sition is unclear.In this study,we investigated the effects of C addition patterns(single or repeated C addition)on soil PE by adding ^(13)C-labeled glucose for 90 d in an incubation experiment with different levels of N application(0,20,and 80 kg N·hm^(-2)·a^(-1)).The different patterns of glucose addition significantly increased soil organic C(SOC)mineralization and produced positive PE.Single glucose addition resulted in stronger PE than repeated addition.PE was significantly weakened with increasing N application levels,indicating that N deposition inhibited soil excitation in Phyllostachys edulis forests.The cumulative PE was significantly negatively correlated withβ-N-acetylaminoglucosidase(NAG)and peroxidase(PEO)activities,and was significantly positively correlated with microbial biomass P(MBP)and potential of hydrogen(pH).Our findings indicated that,when acting together on soil,N application and C addition could strongly affect soil C stocks by stimulating the mineralization of native soil organic matter in subtropical forests.The findings further indicated that single C addition model might overestimate the effect of exogenous readily decomposable organic C on PE and ignore the effect of N deposition on PE,which in turn would overestimate the mineralization loss of forest SOC.
作者
徐敏
刘苑苑
元晓春
曾泉鑫
林惠瑛
吴晓霞
崔琚琰
陈文伟
陈岳民
XU Min;LIU Yuan-yuan;YUAN Xiao-cun;ZENG Quan-xin;LIN Hui-ying;WU Xiao-xia;CUI Ju-yan;CHEN Wen-wei;CHEN Yueh-min(Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology,Fujian Normal University,Fuzhou 350007,China;School of Geographical Science,Fujian Normal University,Fuzhou 350007,China;College of Tourism,Wuyi University,Wuyishan 354300,Fujian,China;Daiyun Mountain National Nature Reserve Administration Bureau,Quanzhou 362500,Fujian,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2022年第10期2619-2627,共9页
Chinese Journal of Applied Ecology
基金
福建省自然科学基金项目(2020J01142,2020J01397)
安徽省自然科学基金项目(2108085QC105)资助。
关键词
激发效应
氮沉降
碳添加模式
酶活性.
priming effect
nitrogen deposition
carbon addition mode
enzymatic activity.
