摘要
【目的】碳(C)、氮(N)和磷(P)在植物生长及调节生理机能等方面起着重要作用,其化学计量特征能够反映植物生长速率和养分限制等。人类活动引起的氮磷沉降对植物、凋落物和土壤的化学计量特征响应机理尚不清楚。因此剖析以植物-凋落物-土壤三者为一个耦合系统C∶N∶P化学计量特征对外源养分添加的响应,能更好地理解植物养分限制和生态系统养分循环动态。【方法】以亚热带退化红壤区杉木(Cunninghamia lanceolata)林为研究对象,在2011年开始布设氮磷添加随机区组试验,为5个区组6个处理共计30个20 m×20 m样地,施肥处理包括N0(CK,只加沙)、N5(5 g/(m^(2)·a))、N10(10 g/(m^(2)·a))、P5(5 g/(m^(2)·a))、N5+P5(N 5 g/(m^(2)·a)+P 5 g/(m^(2)·a))、N10+P5(N 10 g/(m^(2)·a)+P 5 g/(m^(2)·a)),N和P添加分别以NH4NO3和NaH2PO4形式拌沙洒施。在处理后第9年采集植物新鲜叶片、凋落叶片、0~5 cm土壤样品,测定其C、N、P含量及化学计量,量化了叶片的N、P利用效率与再吸收效率,探讨长期N、P添加对杉木植物-凋落物-土壤化学计量特征的影响。【结果】与对照组相比,P添加显著提高植物叶片P含量56.5%,对杉木叶片C、N含量无显著影响,但是降低叶片C/P、N/P;N添加对叶片C、P含量均无显著影响,对C/N、C/P、N/P无显著影响。P添加分别显著提高凋落叶片N、P含量25.7%和51.1%,对C含量没有影响,但降低C/N、C/P、N/P;N添加对凋落叶片C、P和C/N、C/P、N/P均无显著影响。P添加显著提高0~5 cm土壤P含量184.6%,对C、N含量没有影响,但显著降低C/P、N/P;N添加对土壤N含量、C/N、C/P、N/P均无显著影响;而N、P的交互作用对植物、凋落物及土壤的C、N、P含量及其化学计量特征均无显著影响。P添加显著降低了35.3%的植物P的利用效率,但对植物P的再吸收效率无显著影响。随着土壤养分含量的变化,植物、凋落物的内稳态呈现出不同的响应,其中
[Objective]Carbon(C),nitrogen(N)and phosphorus(P)play an important role in plant growth and regulation of physiological functions,and their stoichiometric characteristics can reflect plant growth rate and nutrient limitation.The response mechanism of human-induced nitrogen and phosphorus deposition to the stoichiometric characteristics of plants,litter and soil is unclear.Therefore,analyzing the response of C,N and P stoichiometric characteristics to exogenous nutrient addition in a coupling system of plant-litter-soil,could promote a deeper understanding of plant nutrient restriction and ecosystem nutrient cycling dynamics.[Method]In this study,Cunninghamia lanceolata forest in degraded red soil area of subtropical region was selected as the research objects,and the randomized zone group trials of nitrogen and phosphorus addition was set up since 2011,and a total of 30 plots,each of 20 m×20 m in size,were established by 5 blocks and 6 treatments,the fertilization treatments included N0(CK,only add the sand),N5(5 g/(m^(2)·a)),N10(10 g/(m^(2)·a)),P5(5 g/(m^(2)·a)),N5+P5(N 5 g/(m^(2)·a)+P 5 g/(m^(2)·a)),N10+P5(N 10 g/(m^(2)·a)+P 5 g/(m^(2)·a)).N and P were added in the form of NH4NO3and NaH2PO4,the fertilizer was mixed with clean and dry fine sand and applied to each plot zone(the control plots received fine sand without N and P addition),the fresh leaves,litters and 0-5 cm soil samples were collected in the ninth year after treatment and determined the C,N and P content and stoichiometry,the N and P utilization efficiency and resorption efficiency of leaves were quantified,the effects of long-term N and P addition on the stoichiometric characteristics of fir plants-litter-soil were discussed.[Results]Compared with the control group,the results showed that P addition increased the P content of plant leaves by 56.5%,which had no significant effect on the C and N contents of fir leaves,but reduced the stoichiometric ratios of C/P and N/P.N addition had no significant effect on leaf C and P content,as well as
作者
何佳豪
王方超
张绿水
陈伏生
夏成康
周云烽
全俊旺
沈丽丽
刘俏
HE Jiahao;WANG Fangchao;ZHANG Lüshui;CHEN Fusheng;XIA Chengkang;ZHOU Yunfeng;QUAN Junwang;SHEN Lili;LIU Qiao(College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China;Postdoctoral Station of Management Science and Engineering,Nanchang University,Nanchang 330045,China;Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed,Jiangxi Agricultural University,Nanchang 330045,China)
出处
《江西农业大学学报》
CAS
CSCD
北大核心
2023年第1期134-145,共12页
Acta Agriculturae Universitatis Jiangxiensis
基金
国家自然科学基金项目(32260418,32201533)。
关键词
氮磷添加
红壤丘陵区
杉木
化学计量特征
养分利用
nitrogen and phosphorus addition
red soil hilly area
fir
stoichiometric characteristics
nutrient utilization
