凋落物矿化分解是维持生态系统养分循环的关键过程,也是陆地生态系统C向大气释放的主要动力,因此影响和控制生态系统凋落物矿化分解的主要因素一直备受关注。土地沙漠化是科尔沁沙地最严重的环境问题,并且导致土壤粗质化和贫瘠化,凋落物输入和矿化分解对于改善该地区土壤质地和养分状况至关重要。通过室内培养的方法,对科尔沁沙质草地27种主要植物叶凋落物矿化分解及其与凋落物C含量、N含量、木质素含量、C/N、木质素/N、极易分解有机物含量(LOMⅠ)、中易分解有机物含量(LOMⅡ)及难分解有机物含量(RP)等指标关系进行研究。结果表明:科尔沁沙地27种植物叶凋落物质量存在较大差异(P<0.001),相应的27种植物叶凋落物培养样品矿化有机碳总量和干物质损失量存在显著差异(P<0.001),分别在9.0 mg C·g-1干土至12.7 mg C·g-1干土和14.7%至40.4%之间变化。添加凋落物后培养样品的CO2释放总量显著大于对照(不添加凋落物),说明土壤中添加凋落物后,培养样品的有机碳矿化速率明显增大。27种植物叶凋落物矿化有机碳总量以及损失干物质总量与凋落物的N含量、C/N、木质素/N、LOMⅠ、LOMⅡ和RP等指标存在显著的相关性,叶凋落物的矿化分解主要受LOMⅠ和木质素/N的影响。
Carbon(C) mineralization and decomposition of litters is a critical process to maintain ecosystem nutrients cycling, and drives the large flux of terrestrial C to atmosphere. Therefore, the factors that control the litter decomposition in terrestrial ecosystem are focused on all the time. Horqin Sandy Land is one of the regions that suffering severe land desertification in north China. As a result, soils in this region were coarsened and impoverished. Litter input and subsequent C mineralizing and decomposing would improve soil texture and nutrients in this region. In this study, C mineralization and decomposition of litters from 27 plant species were investigated by adding litter into soil and incubating it in laboratory. Subsequently, we analyzed the correlations of total CO2 release and dry mass loss with C concentration, N concentration, lignin concentration, C/N, lignin/N, labile Pool I and II, and recalcitrant Pool in litter. The results showed that there were big differences in litter quality among 27 plant species, and correspondingly total CO2 release and dry mass loss also differed greatly and varied from 9.0 mg C·g-1 dry soil to 12.7 mg C·g-1 dry soil and from 14.7% to 40.4%, respectively, among 27 plant species. Total CO2 releases after adding litter were significantly larger than the control (non-addition of litter), suggesting that litter input would accelerated C mineralization. Correlation analysis showed that total CO2 release and dry mass loss were significantly correlated with N concentration, C/N, lignin/N, labile pool I and II, and recalcitrant pool in litter of 27 plant species. Stepwise regression, however, suggested that C mineralization and mass loss of litter were mainly controlled by labile pool I and lignin/N in 27 plant species.
[1] Aerts R,van Bodegom P M,Cornelissen J H C.Litter stoichiometric traits of plant species of high-latitude ecosystems show high responsiveness to global change without causing strong variation in litter decomposition[J].New Phytologist,2012,196(1):181-188.
[2] Meier C L,Bowman W D.Links between plant litter chemistry,species diversity,and below-ground ecosystem function[J].Proceedings of the National Academy of Sciences of the United States of America,2008,105(50):19780-19785.
[3] Tan Y L,Chen J,Yan L M,et al.Mass loss and nutrient dynamics during litter decomposition under three mixing treatments in a typical steppe in Inner Mongolia[J].Plant and Soil,2013,366(1/2):107-118.
[4] 张薇,王子芳,王辉,等.土壤水分和植物残体对紫色水稻土有机碳矿化的影响[J].植物营养与肥料学报,2007(6):1013-1019.
[5] Melillo J M,Aber J D,Muratore J F.Nitrogen and lignin control of hardwood leaf litter decomposition dynamics[J].Ecology,1982,63(3):621-626.
[6] Wickings K,Grandy A S,Reed S C,et al.The origin of litter chemical complexity during decomposition[J].Ecology Letters,2012,15(10):1180-1188.
[7] Cleveland C C,Reed S C,Keller A B,et al.Litter quality versus soil microbial community controls over decomposition:a quantitative analysis[J].Oecologia,2014,174(1):283-294.
[8] Dirks I,Navon Y,Kanas D,et al.Atmospheric water vapor as driver of litter decomposition in Mediterranean shrubland and grassland during rainless seasons[J].Global Change Biology,2010,16(10):2799-2812.
[9] Austin A T,Vitousek P M.Precipitation,decomposition and litter decomposability of Metrosideros polymorpha in native forests on Hawai'i[J].Journal of Ecology,2000,88(1):129-138.
[10] Zhou R L,Li Y Q,Zhao H L,et al.Desertification effects on C and N content of sandy soils under grassland in Horqin,northern China[J].Geoderma,2008,145(3/4):370-375.
[11] Zhao H L,Yi X Y,Zhou R L,et al.Wind erosion and sand accumulation effects on soil properties in Horqin Sandy Farmland,Inner Mongolia[J].CATENA,2006,65(1):71-79.
[12] Li L J,Zeng D H,Yu Z Y,et al.Impact of litter quality and soil nutrient availability on leaf decomposition rate in a semi-arid grassland of Northeast China[J].Journal of Arid Environments,2011,75(9):787-792.
[13] Lin G G,Mao R,Zhao L,et al.Litter decomposition of a pine plantation is affected by species evenness and soil nitrogen availability[J].Plant and Soil,2013,373(1/2):649-657.
[14] 苏永中,赵哈林,张铜会,等.不同退化沙地土壤碳的矿化潜力[J].生态学报,2004(2):372-378.
[15] Rovira P,Vallejo V R.Labile and recalcitrant pools of carbon and nitrogen in organic matter decomposing at different depths in soil:an acid hydrolysis approach[J].Geoderma,2002,107(1/2):109-141.
[16] Prescott C E.Litter decomposition:what controls it and how can we alter it to sequester more carbon in forest soils?[J].Biogeochemistry,2010,101(1/3):133-149.
[17] Hossain M Z,Sugiyama S.Influences of plant litter diversity on decomposition,nutrient mineralization and soil microbial community structure[J].Grassland Science,2011,57(2):72-80.
[18] Reynolds B C,Hunter M D.Responses of soil respiration,soil nutrients,and litter decomposition to inputs from canopy herbivores[J].Soil Biology & Biochemistry,2001,33(12/13):1641-1652.
[19] 吴庆标,王效科,欧阳志云.活性有机碳含量在凋落物分解过程中的作用[J].生态环境,2006(6):1295-1299.
[20] Klotzbücher T,Kaiser K,Stepper C,et al.Long-term litter input manipulation effects on production and properties of dissolved organic matter in the forest floor of a Norway spruce stand[J].Plant and Soil,2012,355(1/2):407-416.
[21] 李玉霖,孟庆涛,赵学勇,等.科尔沁沙地植物成熟叶片性状与叶凋落物分解的关系[J].生态学报,2008(6):2486-2494.
[22] Hobbie S E.Nitrogen effects on decomposition:a five-year experiment in eight temperate sites[J].Ecology,2008,89(9):2633-2644.
[23] Zhao H M,Huang G,Ma J,et al.Decomposition of aboveground and root litter for three desert herbs:mass loss and dynamics of mineral nutrients[J].Biology and Fertility of Soils,2014,50(5):745-753.
[24] Solly E F,Schoning I,Boch B,et al.Factors controlling decomposition rates of fine root litter in temperate forests and grasslands[J].Plant and Soil,2014,382(1/2):203-218.
[25] 胡亚林,汪思龙,黄宇,等.凋落物化学组成对土壤微生物学性状及土壤酶活性的影响[J].生态学报,2005 (10):2662-2668.
[26] 史学军,潘剑君,陈锦盈,等.不同类型凋落物对土壤有机碳矿化的影响[J].环境科学,2009(6):1832-1837.
[27] Austin A T,Ballare C L.Dual role of lignin in plant litter decomposition in terrestrial ecosystems[J].Proceedings of the National Academy of Sciences of the United States of America,2010,107(10):4618-4622.
[28] 王旭东,于天富,陈多仁,等.玉米秸秆腐解过程物质组成及胡敏酸的动态变化Ⅰ.物质组成的动态变化[J].干旱地区农业研究,2001(3):78-82.
甘公网安备 62010202000688号