毛竹扩张对日本柳杉林土壤氮矿化速率温度敏感性的影响  

Effects of Moso Bamboo(Phyllostachys edulis)Expansion to Japanese Cedar Forest on Temperature-sensitivity of Soil Nitrogen Mineralization

作　　者：徐健鸿 周波[1,2] 李凯[1,2] 万松泽 XU Jianhong;ZHOU Bo;LI Kai;WAN Songze(Key Laboratory of Forest Ecosystem Protection and Restoration in Poyang Lake Watershed,JiangxiAgricultural University,Nanchang 330045,China;Jiangxi Province Key Laboratory for Bamboo GermplasmResources and Utlization,College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China)

机构地区：[1]江西农业大学鄱阳湖流域森林生态系统保护与修复国家林业和草原局重点实验室,江西南昌330045 [2]江西农业大学林学院/江西省竹子种质资源与利用重点实验室,江西南昌330045

出　　处：《江西农业大学学报》2023年第6期1409-1417,共9页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(41867007);中央财政林业科技推广示范项目(JXTG〔2021〕14)。

摘　　要：【目的】亚热带毛竹扩张对相邻森林造成极大影响,然而毛竹扩张如何影响针叶林土壤氮矿化速率及其稳定敏感性鲜有报道。【方法】在江西马头山国家级自然保护区选择毛竹向日本柳杉林扩张的典型样带,采用野外原位培养和室内恒温培养相结合的方法,探讨毛竹扩张对日本柳杉林土壤氮矿化速率及其温度敏感性的影响。【结果】毛竹向日本柳杉林扩张显著降低土壤氨化速率(P<0.01)和净氮矿化速率(P<0.05),但增加土壤硝化速率(P<0.01)。相关分析的结果显示,土壤氨化速率与降低的土壤有机碳(SOC)含量呈显著正相关关系,而与增加的铵态氮(NH_(4)^(+)-N)含量呈显著负相关关系;土壤硝化速率与降低的土壤含水量(SWC)呈显著正相关关系。毛竹扩张过程中增加土壤N素的来源,削弱植物生长对NH_(4)^(+)-N需求的压力,这可能毛竹扩张降低土壤氨化速率的主要原因。降低的土壤含水量有利于异氧微生物对NO_(3)^(-)-N的固持作用,这可能是毛竹扩张增加土壤硝化速率的主要原因。土壤氮矿化速率的温度敏感性Q10值介于0.80~3.34。毛竹扩张增加土壤氨化速率(P<0.01)和净氮矿化速率(P<0.05)的Q10值,但降低土壤硝化速率的Q10值(P<0.01)。【结论】毛竹具有偏好吸收NH_(4)^(+)-N的特性,随着大气温度的不断升高,NH_(4)^(+)-N可获得性的逐步增加可能是气候变暖背景下毛竹实现种群扩张的重要机制之一。[Objective]Moso bamboo expansion has caused a significant impact on adjacent forest,but there are few reports on how moso bamboo expansion affects the rate of soil nitrogen mineralization and its temperature sensitivity in coniferous forests.[Method]The typical transect of moso bamboo expanding to Japanese cedar forest has been selected in Matoushan National Nature Reserve in Jiangxi Province,and field in-situ incubation and laboratory thermostatic incubation were combined,this study aiming to explore the effects of moso bamboo expansion to Japanese cedar forest on soil nitrogen mineralization rate and temperature sensitivity.[Result]The results showed that moso bamboo expansion significantly decreased the soil N ammonification(P<0.01)and net N mineralization(P<0.05)rates,but it increased the notification rate(P<0.01).Correlation analysis showed that there were positive correlations between N ammonification and the decreased soil organic carbon,however,negative correlated with the increased NH_(4)^(+)-N content.Soil nitrification rate positive correlated with the decreased soil water content.Moso bamboo expansion increased the source of soil nitrogen and weaken the demand of NH_(4)^(+)-N fore plant growth,which may be the main reason for reducing soil ammonification rate.Moreover,the reduced soil water content is beneficial for the fixation of NO_(3)^(-)-N by anaerobic microorganisms,which may be the main reason why bamboo expansion increases soil nitrification rate.In general,Q10 under different forests were ranged from 0.8 to 3.34.[Conclusion]Moso bamboo expansion increased the Q10 of soil net N mineralization and ammonification,while decreased the Q10 of soil nitrification,suggesting that the increase of NH_(4)^(+)-N availability may be one of the important mechanisms for moso bamboo expansion under climate warming,due to its characteristic of preferentially absorbing NH_(4)^(+)-N.

关 键 词：氨化速率 硝化速率 温度敏感性 毛竹扩张 日本柳杉林 

分 类 号：S795.7[农业科学—林木遗传育种]