模拟氮沉降对鄂西南贫营养泥炭地两种藓类植物生长与分解的影响  

Effects of simulated nitrogen deposition on growth and decomposition of two bryophytes in ombrotrophic peatland,southwestern Hubei,China

作　　者：李小玲 朱道明 余玉蓉 吴浩 牟利 洪柳 刘雪飞 卜贵军 薛丹[4] 吴林 LI Xiao-Ling;ZHU Dao-Ming;YU Yu-Rong;WU Hao;MOU Li;HONG Liu;LIU Xue-Fei;BU Gui-Jun;XUE Dan;WU Lin(School of Forestry and Horticulture,Hubei Minzu University,Enshi,Hubei 445000,China;Institute of Chinese Herbal Medicines,Hubei Academy of Agricultural Sciences,Enshi,Hubei 445000,China;The Central Hospital of Enshi Tujia and Miao Autonomous Prefecture,Enshi,Hubei 445000,China;Chinese Academy of Sciences Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization,Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China)

机构地区：[1]湖北民族大学林学园艺学院,湖北恩施445000 [2]湖北省农业科学院中药材研究所,湖北恩施445000 [3]恩施土家族苗族自治州中心医院,湖北恩施445000 [4]中国科学院山地生态恢复与生物资源利用重点实验室,生态恢复与生物多样性保育四川省重点实验室,中国科学院成都生物研究所,成都610041

出　　处：《植物生态学报》2023年第5期644-659,共16页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(41867042)。

摘　　要：以泥炭藓属(Sphagnum)植物为优势种的贫营养泥炭地是陆地生态系统重要的碳汇,其优势植物的生长与分解动态关系着贫营养泥炭地碳汇潜力,但有关氮沉降对贫营养泥炭地优势藓类植物生长与分解的影响还存在很大争议,并且氮沉降对亚热带贫营养泥炭地优势藓类植物生长与分解的研究鲜有报道。该研究以鄂西南贫营养泥炭地为研究对象,通过原位喷洒不同浓度的NH_(4)Cl溶液,采用生物量收割法和分解袋法,探讨模拟氮沉降对泥炭藓(S.palustre)与金发藓(Polytrichumcommune)生长及分解的影响。研究结果表明:(1)氮沉降对两种藓类植物生长高度与生物量均有明显的影响,且两种藓类植物生长存在一定的氮沉降阈值,约为3g·m^(-2)·a^(-1);(2)氮沉降对两种藓类植物生长影响程度不同,金发藓对氮沉降的响应灵敏度要大于泥炭藓;(3)高浓度氮沉降(6和12g·m^(-2)·a^(-1))抑制了泥炭藓分解,低浓度氮沉降(3g·m^(-2)·a^(-1))对泥炭藓分解的影响取决于分解时间,而所有浓度氮沉降均抑制了金发藓凋落物的分解;(4)分解1年以后,泥炭藓的最终质量残留率平均值为105.99%,金发藓的最终质量残留率平均值为70.79%,金发藓的分解速率远大于泥炭藓;(5)氮沉降对两种藓类凋落物化学元素含量与化学计量比有显著影响,且与分解时间密切相关。Aims Ombrotrophic peatlands,dominated by Sphagnum,are important carbon sinks in terrestrial ecosystems.The dynamics of growth and decomposition of dominant plants usually determine the carbon sink potential of ombrotrophic peatland.However,it is still controversial how nitrogen deposition impact on the growth and decomposition of mosses in ombrotrophic peatland.Moreover,the effects of nitrogen deposition on the growth and decomposition of dominant mosses are rarely reported in subtropical ombrotrophic peatlands.Methods We selected an ombrotrophic peatland in southwestern Hubei Province as the study area.Different concentrations of NH_(4)Cl solution were sprayed in situ.Here biomass harvesting and decomposition bag methods were adopted to estimate growth and litter decomposition of S.palustre and Polytrichum commune.Important findings(1)Nitrogen deposition had obvious effects on the height and biomass of the two mosses.Moreover,there was a threshold value of nitrogen deposition at the level of about 3 g·m^(-2)·a^(-1).(2)The effects of nitrogen deposition on the growth of the two mosses were different,and the response sensitivity of S.palustre to nitrogen deposition was greater than that of P.commune.(3)High nitrogen deposition levels(i.e.,6 and 12 g·m^(-2)·a^(-1))inhibited the decomposition of S.palustre,while the effect of low nitrogen deposition(i.e.,3 g·m^(-2)·a^(-1))on the decomposition of S.palustre depends on time.All the concentrations of nitrogen deposition inhibited the decomposition of P.commune litter.(4)After one year of decomposition,the average final mass residual percentage of S.palustre was 105.99%,and 70.79%for P.commune.The decomposition rate of P.commune was much higher than that of S.palustre.(5)Nitrogen deposition significantly affected the chemical element content and stoichiometric ratio of the two moss litters,and was closely related to decomposition time.

关 键 词：泥炭藓沼泽 分解 苔藓 氮输入 生产 

分 类 号：Q948[生物学—植物学]