氮添加对杉木林土壤有机碳矿化速率及酶动力学参数温度敏感性的影响  

Effects of nitrogen additions on the temperature sensitivities of soil organic carbon mineralization rates and enzyme kinetic parameters in Chinese fir plantations

作　　者：董清馨 张心昱[1,2] 王辉民 付晓莉[1,2] 郭志明 陈伏生[3] DONG Qingxin;ZHANG Xinyu;WANG Huimin;FU Xiaoli;GUO Zhiming;CHEN Fusheng(Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beifing 100190,China;Jiangxi Provincial Key Laboratory for Bamboo Germplasm Resources and Utilization,Jiangxi Agricultural University,Nanchang 330045,China)

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [2]中国科学院大学资源与环境学院,北京100190 [3]江西农业大学江西省竹子种质资源与利用重点实验室,南昌330045

出　　处：《生态学报》2018年第18期6502-6510,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41571251;41571130043);中科院技术创新项目(201604)

摘　　要：为探讨氮添加对亚热带森林土壤有机碳矿化速率(Cmin)及酶动力学参数温度敏感性(Q10)的影响,选择亚热带杉木林土壤为研究对象,采用野外长期氮添加与室内控温培养试验,分析土壤Cmin及β^(-1),4-葡萄糖苷酶(βG)动力学参数温度敏感性。野外试验设置对照(N0)、低氮(N1:50 kg N hm^(-2)a^(-1))、高氮(N2:100 kg N hm^(-2)a^(-1)) 3种处理,每种处理3次重复,室内培养设置10—40℃。结果表明:(1)氮添加增加土壤Cmin,为N2>N1>N0,但其Q10(Cmin)差异不显著。(2)氮添加增加βG的潜在最大反应速率(Vmax)和催化效率(Vmax/Km),且Vmax和Vmax/Km均为N2>N1>N0,而氮添加对半饱和常数(Km)影响不显著。Q10(Vmax)和Q10(Km)大小为N2>N1>N0且差异显著,但是Q10(Vmax/Km)无显著差异。(3)相关分析表明,30℃培养温度下,Cmin和全磷(TP)、硝态氮(NO-3-N)、有效磷(a P)、Vmax正相关; Vmax和TP、NO-3-N正相关,和p H负相关; Km和全氮(TN)负相关; Vmax/Km和p H负相关,和TP正相关。30—40℃培养温度下,Q10(Vmax)和p H负相关,Q10(Vmax/Km)和TN负相关。研究可为氮沉降背景下土壤碳素循环的生物化学过程对增温响应的模型提供重要参数。In recent years, nitrogen deposition has increased industrial development, and production and use of artificial globally because of the worldwide combustion of fossil fuels, nitrogen fertilizers. Nitrogen deposition can not only promote organic mineralization and increase nutrient availability, but can also cause soil acidification and nitrate leaching, once nitrogen input overcomes the accumulation ability of plants and soil microorganisms in ecosystems （ i. e., nitrogen saturation）. The objective of this study was to investigate the responses of temperature sensitivities （ Q10 ） of soil organic carbon mineralization rates （ Cmin ） and enzyme kinetic parameters to nitrogen additions in a subtropical forest. We selected soil samples from a long-term field nitrogen addition experiment conducted in the subtropical soil of Chinese fir plantations. The three nitrogen addition treatments, i.e., control （NO）, low nitrogen （N1 ： 50 kg N hm^-2 a^-1 ）, and high nitrogen （N2： 100 kg N hm^-2 a^-1）, were established in 2011 with three 20 m × 20 m replicate plots for each treatment. The soil samples were incubated at 10-40℃ in the laboratory to measure Q10 of Cmin and 13-1,4-glucosidase （15G） kinetic parameters. The results showed that （ 1 ） the nitrogen additions increased Cmin, which varied as N2 〉 N1 〉 NO, but the differences between the Q10 （Cmin） values were not significant. （2） The nitrogen additions increased the maximum rates of velocity （Vmax） and catalytic efficiencies （Vmax/Km） as N2 〉 N1 〉 NO; this was consistent with the soil Cmin, but the nitrogen additions had no significant effect on the half-saturation constant （Km）. The Q10（Vmax） and Q10（Km） values varied as N2 〉 N1 〉 NO, but the Q10 （Vmax/Km） value showed no significant differences between the N addition treatments. （3） At 30℃, the correlation analyses showed that the Cmin values were positively correlated with the total phosphorus （TP）, nitrate nitrogen （NO3^--N�

关 键 词：氮添加 有机碳矿化速率 酶动力学参数 温度敏感性 杉木林 

分 类 号：S714[农业科学—林学]