模拟雪被变化对红桦和四川红杉凋落叶碳氮磷释放动态的影响  

Effects of simulated snow cover changes on leaf litter carbon,nitrogen,and phosphorus release of Betula albosinensis Burkill and Larix mastersiana Rehder&E.H.Wilson

作　　者：陈玉莲 杜婷 张玉[1] 游成铭 张丽[1] 谭波[1] 徐振锋[1] 李晗[1] CHEN Yulian;DU Ting;ZHANG Yu;YOU Chengming;ZHANG Li;TAN Bo;XU Zhenfeng;LI Han(Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province,Institute of Ecology&Forestry,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学生态林业研究所,长江上游林业生态工程四川省重点实验室,成都611130

出　　处：《应用与环境生物学报》2024年第1期90-97,共8页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(3190129);四川省自然科学基金项目(2022NSFSC099和2022NSFSC0083)资助。

摘　　要：凋落叶碳和养分的归还是森林生态系统物质循环的重要环节,且可能受到气候变暖所引发雪被格局变化的影响.通过野外雪被控制(雪被减少和雪被去除)和凋落物分解实验,探究亚高山森林落叶树种红桦(Betula albosinensis Burkill)和四川红杉(Larix mastersiana Rehder&E.H.Wilson)凋落叶分解过程中碳(C)、氮(N)、磷(P)释放动态在各关键时期(雪被形成期、覆盖期、融化期和生长季)对雪被变化的响应.结果表明:红桦和四川红杉凋落叶在分解第一年呈现C释放和N、P累积,其中,C含量减少了8.7%-11.5%,N、P含量分别增加了25.0%-36.4%和21.2%-43.4%.分解一年后,相较于自然雪被,凋落叶C在雪被减少和去除条件下释放更快,而N、P累积更少.不同物种凋落叶在分解过程中表现出不同趋势,红桦凋落叶N、P在冬季即开始呈现富集,而四川红杉N、P的富集延后发生在生长季.另外,混合线性模型和相关性分析结果表明雪被、分解时期、物种及三者之间的交互作用显著影响了凋落叶C、N、P的变化,其释放率与日均温显著相关,且N释放率与凋落叶初始质量显著相关.综上所述,雪被的减少促进了红桦和四川红杉凋落叶早期分解过程中C的释放,但抑制了N、P的富集,表明气候变暖情境下雪被减少可能通过改变凋落叶碳和养分释放进而影响亚高山森林生态系统的生物地球化学循环过程.Carbon(C)and nutrient release during litter decomposition play important roles in material cycling in forest ecosystems and may be affected by snow cover changes caused by global warming.We conducted field snow manipulation(snow reduction and snow removal)and litter decomposition experiments to investigate the effects of snow cover changes on C,nitrogen(N)and phosphorus(P)release from decomposing deciduous litters of Betula albosinensis Burkill and Larix mastersiana Rehder&E.H.Wilson during each critical period(snow formation,cover,melt stage,and growing season)in a subalpine forest.C release and N and P accumulation were observed in the first year of decomposition,with C content decreasing by 8.7%–11.5%and N and P contents increasing by 25.0%–36.4%and 21.2%–43.4%,respectively.After the entire year of decomposition,compared to that in the control,litter C was released more rapidly under snow cover reduction and removal conditions,whereas N and P accumulated less.B.albosinensis litter N and P started to accumulate in winter,whereas L.mastersiana accumulation was delayed until the growing season.In addition,the results of the mixed linear model and correlation analysis showed that snow cover,decomposition period,species,and the interaction among them significantly influenced the changes in C,N,and P in the litter;the release rate was significantly correlated with the mean daily temperature,while the N release rate was significantly correlated with the initial litter quality.The collective findings indicate that snow reduction can promote the release of C during the early decomposition of the two leaf litter types but inhibit the enrichment of N and P.These results indicate that a decrease in snow cover due to global warming may influence biogeochemical cycling processes by altering C and nutrient release during litter decomposition in subalpine forest ecosystems.

关 键 词：雪被减少 凋落叶分解 碳 氮 亚高山森林 

分 类 号：S718.5[农业科学—林学]