摘要
研究模拟氮(N)沉降下森林生态系统凋落物-土壤C/N/P化学计量特征,对探究在全球气候变化背景下森林生态系统物质循环内在机理具有重要科学意义。以滇中亚高山华山松林(Pinus armandii forest)为研究对象,采用尼龙网袋法于2018年2月-2019年1月在华山松林开展模拟N沉降下凋落叶、枝原位分解试验,分别设置4个N沉降水平:对照CK(N 0g·m^(-2)·a^(-1))、低氮LN(N 5 g·m^(-2)·a^(-1))、中氮MN(N 15 g·m^(-2)·a^(-1))和高氮HN(N 30 g·m^(-2)·a^(-1))。结果表明:华山松林凋落叶和枝C元素均为直接释放模式;凋落叶和枝N元素分别为淋溶-富集-释放和富集-释放模式;凋落叶和枝P元素分别为淋溶-富集-释放和富集-释放模式;凋落叶的C、N、P养分释放速率(40.71%、53.83%、47.06%)均高于凋落枝(20.98%、22.04%、13.15%);各N处理下,凋落叶和枝C释放速率均表现为LN>MN>CK>HN;N沉降总体增加了凋落叶C、N含量,但对P含量无显著影响;N沉降显著降低了凋落叶ω(C)/ω(N)和ω(N)/ω(P)、凋落枝ω(C)/ω(N);凋落叶、枝N、P含量与土壤N、P含量密切相关,土壤P对凋落叶化学计量影响最大,土壤N对凋落枝化学计量影响最大,土壤C对凋落物化学计量影响最小。在短期内N沉降能抑制凋落物分解过程中C、N、P的释放,但对土壤化学计量特征无明显影响,滇中华山松林凋落物分解过程中的化学计量变化特征及养分释放的研究有助于了解森林生态系统对N沉降的响应机理,特别是土壤N、P对凋落物分解的影响将为后续研究的重点内容。
To study the C/N/P stoichiometric characteristics of forest litter and soil under simulated nitrogen(N)deposition is of great scientific significance for exploring the internal mechanism of forest ecosystem material cycle under the background of global climate change.Pinus armandii forest in subalpine forests in central Yunnan was as the research object in this study.In-situ decomposition of litter leaves and twigs under simulated N deposition was carried out using the nylon mesh bags method in February 2018 to January 2019.Four treatment levels of N deposition were applied,i.e.,control(CK,0 g·m^(-2)·a^(-1)),low(LN,5 g·m^(-2)·a^(-1)),medium(MN,15 g·m^(-2)·a^(-1)),and high(HN,30 g·m^(-2)·a^(-1))nitrogen deposition.The results indicated that the C element in litter leaves and twigs of Pinus armandii forest was released directly;the N elements in litter leaves and twigs showed"leaching-enrichment-release"and"enrichment-release"modes,respectively;the P element in litter leaves and twigs showed"leaching-enrichment-release"and"enrichment-release",respectively;the nutrient release rates of C,N and P in litter leaves(40.71%,53.83%,47.06%)were all higher than those in twigs(20.98%,22.04%,13.15%);under each N treatment,the C release rate of litter leaves and twigs were as follows:LN>MN>CK>HN;N deposition increased the contents of C and N in litter leaves,but had no significant effect on P content;N deposition significantly decreasedω(C)/ω(N)andω(N)/ω(P)of litter leaves andω(C)/ω(N)of litter twigs;the contents of N and P in litter leaves and twigs were closely related to the contents of N and P in soils;P content in soil had the greatest influence on the stoichiometry of litter leaves,soil N had the greatest influence on the stoichiometry of litter twigs,and soil C had the least influence on the stoichiometry of litters.N deposition in the short term can inhibit litter decomposition in the process of the release of C,N,P,but had no obvious effect on soil chemical metrology characteristics.The study on the characteristics of stoichiometric changes and nutrient release during litter decomposition in Pinus armandii forest in central Yunnan is helpful to understand the response mechanism of forest ecosystem to N deposition.In particular,the influence of soil N and P on litter decomposition will be the focus of subsequent research.
作者
潘禹
王克勤
宋娅丽
张雨鉴
郑兴蕊
PAN Yu;WANG Keqin;SONG Yali;ZHANG Yujian;ZHENG Xingrui(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,China)
出处
《生态环境学报》
CSCD
北大核心
2021年第3期492-502,共11页
Ecology and Environmental Sciences
基金
南省教育厅研究生科学研究基金项目(2019Y0134)
云南省科技厅“三区”人才支持计划
云南省高校优势特色重点学科(生态学)建设项目(050005113111)
国家林草局林业科技创新平台运行项目:云南玉溪森林生态系统国家定位观测研究站(2020132078)
云南玉溪森林生态系统国家长期科研基地(2020132550)。
关键词
N沉降
凋落物
化学计量特征
养分释放
华山松林
滇中
nitrogen deposition
litter
stoichiometric characteristics
nutrient release
Pinus armandii forest
central Yunnan
