雪被去除减缓岷江冷杉凋落叶易分解碳释放  

Reduced release of labile carbon from Abies fargesii var.faxoniana needle litter after snow removal in an alpine forest

作　　者：赖硕钿 吴福忠 吴秋霞 朱晶晶 倪祥银 LAI Shuo-Tian;WU Fu-Zhong;WU Qiu-Xia;ZHU Jing-Jing;NI Xiang-Yin(School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fuzhou 350007,China;Fujian Sanming Forest Ecosystem National Observation and Research Station,Sanming,Fujian 365002,China)

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]湿润亚热带生态-地理过程教育部重点实验室,福州350007 [3]福建三明森林生态系统国家野外科学观测研究站,福建三明365002

出　　处：《植物生态学报》2023年第5期672-686,共15页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(32022056、31800521、32101509和32171641)。

摘　　要：气候变化已经并将持续改变寒冷生物区季节性雪被厚度和覆盖时间,雪被厚度的减少可能影响高山森林凋落物分解,尤其是其早期分解过程中易分解碳的释放。该文研究了川西高山森林雪被去除处理后优势树种岷江冷杉(Abiesfargesii var.faxoniana)凋落叶总有机碳、热水/冷水可溶性有机碳、非结构性碳(可溶性糖、淀粉)在冬季(雪被形成期、覆盖期、融化期)和生长季(初期、中期、后期)的释放规律。结果表明:(1)经过一年的分解,对照和雪被去除处理的凋落叶质量残留量分别为76.4%和86.2%,总有机碳残留量分别为60.5%和74.8%。(2)经过一个冬季分解后,雪被去除处理降低了凋落叶热水溶性有机碳和可溶性糖的释放,而增加了总有机碳、可溶性有机碳、非结构性碳和淀粉的富集。(3)经过生长季分解后,雪被去除处理降低了凋落叶易分解碳释放,其中总有机碳、热水溶性有机碳、可溶性有机碳、非结构性碳、可溶性糖和淀粉的释放分别降低了36.3%、0.8%、43.7%、28.3%、21.7%和33.7%。偏最小二乘法分析表明,岷江冷杉凋落叶易分解碳释放受土壤冻融循环次数、脲酶活性、土壤温度和可溶性有机碳含量影响显著。以上结果说明冬季雪被覆盖促进了高山森林凋落叶易分解碳释放,表明高山森林冬季雪被格局的改变将显著影响地表凋落叶分解过程,且这种影响将持续作用于生长季凋落叶碳释放,深刻影响高山森林土壤生物地球化学过程。Aims Changes in the depth and duration of seasonal snowpack induced by climate change may affect litter decomposition,particularly the release of labile carbon during the early decomposition periods in alpine forests.Our objective of this study was to assess the effect of snow removal on labile carbon fractions in litter(i.e.,dissolved organic carbon(DOC),hot-water extractable carbon(HWEC)and non-structural carbon(NSC))during early stage of litter decomposition in an alpine forest on the eastern Qingzang Plateau.Methods An in situ litter input microcosm experiment was conducted in an alpine forest dominated by 120 to 150-year-old fir(Abies fargesii var.faxoniana)from October 2018 to October 2019.Air-dried fir needle litter was incubated at control and snow removal plots and the concentrations of total organic carbon(TOC),DOC,HWEC,NSC,soluble sugars and starch in decomposing fir litter were determined during winter(snow formation period,snow coverage period and snow melt period)and growing season(early,middle and late growing season).Important findings Results showed that litter mass remained by 76.4%and 86.2%at control and snow removal plots,respectively,over one year of decomposition.After decomposition for one year,60.5%and 74.8%of organic carbon remained in decomposing litter at control and snow removal plots,respectively.After decomposition for a winter,the release of HWEC and soluble sugars from decomposing litter were lower,while TOC,DOC,NSC and starch in fir needle litter were higher in snow removal plots than that in control plot.After decomposition for a growing season,the release of TOC,HWEC,DOC,NSC,soluble sugars and starch were reduced by 36.3%,0.8%,43.7%,28.3%,21.7%and 33.7%,respectively,in the snow removal plots compared to those in the control plots.The results from partial least square model indicated that labile carbon release was strongly controlled by soil freezing-thawing cycle,urease activity,soil temperature and DOC concentration.These results suggest that the presence of snow cover accelera

关 键 词：雪被去除 凋落针叶分解 易分解碳 非结构性碳 高山森林 

分 类 号：S714[农业科学—林学]