长白山垂直带森林叶片-凋落物-土壤连续体有机碳动态——基于稳定性碳同位素分析
|
摘要
稳定性碳同位素自然丰度(δ~(13)C)记录着生态系统碳循环过程的关键信息,常被用于评价全球变化情景下陆地生态系统碳的动态。以长白山北坡垂直带4种典型森林生态系统为研究对象,测定乔木建群种叶片、凋落物以及不同深度土壤有机碳(SOC)含量和δ~(13)C值,探讨植物叶片-凋落物-土壤连续体碳含量、δ~(13)C丰度的分布格局及其生态学暗示。研究结果表明:植物叶片碳含量随海拔高度的增加呈现抛物线型变化,且阔叶树叶片碳含量显著低于针叶树,体现气候要素和植被功能型的支配作用,并且暗示针叶树种潜在的碳蓄积能力更强。此外,植物叶片δ~(13)C随海拔高度升高而降低,表明高海拔植物叶片水分利用效率较低,即固碳耗水成本更高。凋落物碳含量随海拔增加逐渐下降,而矿质表层土壤则表现为阔叶红松林、岳桦林显著高于暗针叶林,体现了植被类型和土壤质地的共同支配作用。总体上,岳桦林SOC周转最快,其次是暗针叶林,位于基带的阔叶红松林最慢。可见,小尺度上气候因子并不是温带森林地下碳循环的主导因素,植被功能型和土壤属性对SOC周转与稳定的影响更大。在探讨环境因子对陆地生态系统碳循环和碳平衡的影响时需要考虑研究尺度,不同的研究尺度影响SOC周转的驱动因子并不相同。研究方法方面,基于log SOC和δ~(13)C的SOM周转模型能够很好地概括不同生态系统类型下SOM周转的相对快慢,可用来评价SOC动态对全球变化的响应。
The natural abundance of the stable carbon isotope( δ~(13)C) records key information regarding the ecosystem carbon( C) cycle and is commonly used to assess the C dynamics in terrestrial ecosystems under global change. In this study,we selected four typical forest ecosystems along the vertical transect distributed in Changbai Mountain and measuredthe C concentrations and δ~(13)C values of leaves of constructive tree species,litter,and soils at different soil layers. The aim of this study was to explore the patterns of C content and δ~(13)C values in the leaf-litter-soil continuum,as well as their ecological indications. The results showed that foliar C content first increased and then decreased with the increasing altitude,and the parabolic peak appeared at the Ermans birch-spruce-fir forest stand; moreover, the C content of broadleaved tree species was significantly lower than that of coniferous species,reflecting that coniferous species had a higher C sequestration capacity relative to that of broadleaved species. Climatic factors and vegetation types dominated the pattern of foliar C content. In addition,foliar δ~(13)C decreased with increasing altitude,indicating that vegetation at highaltitude sites had lower water use efficiency( WUE) and higher water consumption by C sequestration relative to that at low altitude sites. Litter C content gradually decreased with increase in altitude,whereas topsoil C content at the 0—20 cm depth at the broad-leaved Korean pine forest( BLKP) and Ermans birch forest( EB) was higher than that of the Korean pine-spruce-fir forest( KPSF) and Ermans birch-spruce-fir forest( EBSF),reflecting the predominance of vegetation type and soil texture together. Overall,the birch forest had the highest SOC turnover rate,followed by that of the two dark coniferous forests,and that of the broad-leaved Korean pine forest was the lowest. Our results suggest that climatic factors are not the predominant factors in the belowground C cycle of temperate forests at a small scale,and vegetation functional types and soil properties could have greater effects on the turnover and stability of SOC. Because the factors driving the turnover of SOC are not the same at different study scales,we should more intensively consider the research scale when we explore the effects of environmental factors on C cycle and C budget in terrestrial ecosystems. The SOM turnover model,based on the regression of log SOC and δ~(13)C,is a good method to characterize the rate of SOM turnover in various ecosystems,which can be used to evaluate the response of SOC dynamics to global change.
The natural abundance of the stable carbon isotope( δ~(13)C) records key information regarding the ecosystem carbon( C) cycle and is commonly used to assess the C dynamics in terrestrial ecosystems under global change. In this study,we selected four typical forest ecosystems along the vertical transect distributed in Changbai Mountain and measuredthe C concentrations and δ~(13)C values of leaves of constructive tree species,litter,and soils at different soil layers. The aim of this study was to explore the patterns of C content and δ~(13)C values in the leaf-litter-soil continuum,as well as their ecological indications. The results showed that foliar C content first increased and then decreased with the increasing altitude,and the parabolic peak appeared at the Ermans birch-spruce-fir forest stand; moreover, the C content of broadleaved tree species was significantly lower than that of coniferous species,reflecting that coniferous species had a higher C sequestration capacity relative to that of broadleaved species. Climatic factors and vegetation types dominated the pattern of foliar C content. In addition,foliar δ~(13)C decreased with increasing altitude,indicating that vegetation at highaltitude sites had lower water use efficiency( WUE) and higher water consumption by C sequestration relative to that at low altitude sites. Litter C content gradually decreased with increase in altitude,whereas topsoil C content at the 0—20 cm depth at the broad-leaved Korean pine forest( BLKP) and Ermans birch forest( EB) was higher than that of the Korean pine-spruce-fir forest( KPSF) and Ermans birch-spruce-fir forest( EBSF),reflecting the predominance of vegetation type and soil texture together. Overall,the birch forest had the highest SOC turnover rate,followed by that of the two dark coniferous forests,and that of the broad-leaved Korean pine forest was the lowest. Our results suggest that climatic factors are not the predominant factors in the belowground C cycle of temperate forests at a small scale,and vegetation functional types and soil properties could have greater effects on the turnover and stability of SOC. Because the factors driving the turnover of SOC are not the same at different study scales,we should more intensively consider the research scale when we explore the effects of environmental factors on C cycle and C budget in terrestrial ecosystems. The SOM turnover model,based on the regression of log SOC and δ~(13)C,is a good method to characterize the rate of SOM turnover in various ecosystems,which can be used to evaluate the response of SOC dynamics to global change.
引文
[1]金峰,杨浩,赵其国.土壤有机碳储量及影响因素研究进展.土壤,2000,32(1):11-17.
[2]Schlesinger W H.Evidence from chronosequence studies for a low carbon-storage potential of soils.Nature,1990,348(6298):232-234.
[3]Lal R.Forest soils and carbon sequestration.Forest Ecology and Management,2005,220(1/3):242-258.
[4]Smolander A,Kitunen V.Soil microbial activities and characteristics of dissolved organic C and N in relation to tree species.Soil Biology and Biochemistry,2002,34(5):651-660.
[5]Deng X W,Han S J,Hu Y L,Zhou Y M.Carbon and nitrogen transformations in surface soils under Ermans birch and dark coniferous forests.Pedosphere,2009,19(2):230-237.
[6]Bernoux M,Cerri C C,Neill C,de Moraes J F L.The use of stable carbon isotopes for estimating soil organic matter turnover rates.Geoderma,1998,82(1/3):43-58.
[7]Jobbágy E G,Jackson R B.The vertical distribution of soil organic carbon and its relation to climate and vegetation.Ecological Applications,2000,10(2):423-436.
[8]Balesdent J,Girardin C,Mariotti A.Site-relatedδ13C of tree leaves and soil organic-matter in a temperate forest.Ecology,1993,74(6):1713-1721.
[9]Michener R,Lajtha K.Stable Isotopes in Ecology and Environmental Science.2nd ed.Malden,MA:John Wiley&Sons,2007:1-594.
[10]Fang H J,Yu G R,Cheng S L,Mo J M,Yan J H,Li S G.13C abundance,water-soluble and microbial biomass carbon as potential indicators of soil organic carbon dynamics in subtropical forests at different successional stages and subject to different nitrogen loads.Plant and Soil,2009,320(1/2):243-254.
[11]Fang H J,Cheng S L,Yu G R,Yang X M,Xu M J,Wang Y S,Li L S,Dang X S,Wang L,Li Y N.Nitrogen deposition impacts on the amount and stability of soil organic matter in an alpine meadow ecosystem depend on the form and rate of applied nitrogen.European Journal of Soil Science,2014,65(4):510-519.
[12]Del Galdo I,Six J,Peressotti A,Cotrufo M F.Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable C isotopes.Global Change Biology,2003,9(8):1204-1213.
[13]Gaudinski J B,Trumbore S E,Davidson E A,Zheng S H.Soil carbon cycling in a temperate forest:radiocarbon-based estimates of residence times,sequestration rates and partitioning of fluxes.Biogeochemistry,2000,51(1):33-69.
[14]Trumbore S,Chadwick O A,Amundson R.Rapid exchange between soil carbon and atmospheric carbon dioxide driven by temperature change.Science,1996,272(5260):393-396.
[15]Richter D D,Markewitz D,Trumbore S E,Wells C G.Rapid accumulation and turnover of soil carbon in a re-establishing forest.Nature,1999,400(6739):56-58.
[16]于贵瑞.人类活动与生态系统变化的前沿科学问题.北京:高等教育出版社,2009:1-543.
[17]Cheng S L,Fang H J,Yu G R,Zhu T H,Zheng J J.Foliar and soil15N natural abundances provide field evidence on nitrogen dynamics in temperate and boreal forest ecosystems.Plant and Soil,2010,337(1/2):285-297.
[18]Wang Z,Xu Z B,Li X,Peng D,Tan Z.The main forest types and their features of community structure in northern slope of Changbai Mountain.Forest Ecosystem Research,1980,(1):25-42.
[19]Amundson R,Baisden W T.Stable isotope tracers and mathematical models in soil organic matter studies//Sala O E,Jackson R B,Mooney H A,Howarth R W,eds.Methods in Ecosystem Science.New York:Springer,2000:117-137.
[20]Garten C T Jr,Cooper L W,Post W M III,Hanson P J.Climate controls on forest soil C isotope ratios in the southern Appalachian Mountains.Ecology,2000,81(4):1108-1119.
[21]Powers J S,Schlesinger W H.Geographic and vertical patterns of stable carbon isotopes in tropical rain forest soils of Costa Rica.Geoderma,2002,109(1/2):141-160.
[22]Chapin F S III,Matson P A,Vitousek P.Principles of Terrestrial Ecosystem Ecology.New York:Springer,2011:1-546.
[23]He J S,Fang J Y,Wang Z H,Guo D L,Flynn D F B,Geng Z.Stoichiometry and large-scale patterns of leaf carbon and nitrogen in the grassland biomes of China.Oecologia,2006,149(1):115-122.
[24]Bai Y F,Wu J G,Clark C M,Pan Q M,Zhang L X,Chen S P,Wang Q B,Han X G.Grazing alters ecosystem functioning and C:N:P stoichiometry of grasslands along a regional precipitation gradient.Journal of Applied Ecology,2012,49(6):1204-1215.
[25]Ripullone F,Lauteri M,Grassi G,Amato M,Borghetti M.Variation in nitrogen supply changes water-use efficiency of Pseudotsuga menziesii and Populus x euroamericana;a comparison of three approaches to determine water-use efficiency.Tree Physiology,2004,24(6):671-679.
[26]Yu G R,Song X,Wang Q F,Liu Y F,Guan D X,Yan J H,Sun X M,Zhang L M,Wen X F.Water-use efficiency of forest ecosystems in eastern China and its relations to climatic variables.New Phytologist,2008,177(4):927-937.
[27]Arai H,Tokuchi N.Factors contributing to greater soil organic carbon accumulation after afforestation in a Japanese coniferous plantation as determined by stable and radioactive isotopes.Geoderma,2010,157(3/4):243-251.
[28]黄昌勇,徐建明.土壤学(第三版).北京:中国农业出版社,2010:1-379.
[29]Zhang M,Zhang X K,Liang W J,Jiang Y,Dai G H,Wang X G,Han S J.Distribution of soil organic carbon fractions along the altitudinal gradient in Changbai Mountain,China.Pedosphere,2011,21(5):615-620.
[30]Blair G J,Lefroy R D B,Lisle L.Soil carbon fractions based on their degree of oxidation,and the development of a carbon management index for agricultural systems.Australian Journal of Agricultural Research,1995,46(7):1459-1466.
[31]Yang Y H,Mohammat A,Feng J M,Zhou R,Fang J Y.Storage,patterns and environmental controls of soil organic carbon in China.Biogeochemistry,2007,84(2):131-141.
[32]Ehleringer J R,Buchmann N,Flanagan L B.Carbon isotope ratios in belowground carbon cycle processes.Ecological Applications,2000,10(2):412-422.
[33]Liu W G,Feng X H,Ning Y F,Zhang Q L,Cao Y N,An Z S.δ13C variation of C3and C4plants across an Asian monsoon rainfall gradient in arid northwestern China.Global Change Biology,2005,11(7):1094-1100.
[34]于贵瑞,王绍强,陈泮勤,李庆康.碳同位素技术在土壤碳循环研究中的应用.地球科学进展,2005,20(5):568-577.
[35]Gao J Q,Lei G C,Zhang X W,Wang G X.Canδ13C abundance,water-soluble carbon,and light fraction carbon be potential indicators of soil organic carbon dynamics in Zoigêwetland?Catena,2014,119:21-27.
[2]Schlesinger W H.Evidence from chronosequence studies for a low carbon-storage potential of soils.Nature,1990,348(6298):232-234.
[3]Lal R.Forest soils and carbon sequestration.Forest Ecology and Management,2005,220(1/3):242-258.
[4]Smolander A,Kitunen V.Soil microbial activities and characteristics of dissolved organic C and N in relation to tree species.Soil Biology and Biochemistry,2002,34(5):651-660.
[5]Deng X W,Han S J,Hu Y L,Zhou Y M.Carbon and nitrogen transformations in surface soils under Ermans birch and dark coniferous forests.Pedosphere,2009,19(2):230-237.
[6]Bernoux M,Cerri C C,Neill C,de Moraes J F L.The use of stable carbon isotopes for estimating soil organic matter turnover rates.Geoderma,1998,82(1/3):43-58.
[7]Jobbágy E G,Jackson R B.The vertical distribution of soil organic carbon and its relation to climate and vegetation.Ecological Applications,2000,10(2):423-436.
[8]Balesdent J,Girardin C,Mariotti A.Site-relatedδ13C of tree leaves and soil organic-matter in a temperate forest.Ecology,1993,74(6):1713-1721.
[9]Michener R,Lajtha K.Stable Isotopes in Ecology and Environmental Science.2nd ed.Malden,MA:John Wiley&Sons,2007:1-594.
[10]Fang H J,Yu G R,Cheng S L,Mo J M,Yan J H,Li S G.13C abundance,water-soluble and microbial biomass carbon as potential indicators of soil organic carbon dynamics in subtropical forests at different successional stages and subject to different nitrogen loads.Plant and Soil,2009,320(1/2):243-254.
[11]Fang H J,Cheng S L,Yu G R,Yang X M,Xu M J,Wang Y S,Li L S,Dang X S,Wang L,Li Y N.Nitrogen deposition impacts on the amount and stability of soil organic matter in an alpine meadow ecosystem depend on the form and rate of applied nitrogen.European Journal of Soil Science,2014,65(4):510-519.
[12]Del Galdo I,Six J,Peressotti A,Cotrufo M F.Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable C isotopes.Global Change Biology,2003,9(8):1204-1213.
[13]Gaudinski J B,Trumbore S E,Davidson E A,Zheng S H.Soil carbon cycling in a temperate forest:radiocarbon-based estimates of residence times,sequestration rates and partitioning of fluxes.Biogeochemistry,2000,51(1):33-69.
[14]Trumbore S,Chadwick O A,Amundson R.Rapid exchange between soil carbon and atmospheric carbon dioxide driven by temperature change.Science,1996,272(5260):393-396.
[15]Richter D D,Markewitz D,Trumbore S E,Wells C G.Rapid accumulation and turnover of soil carbon in a re-establishing forest.Nature,1999,400(6739):56-58.
[16]于贵瑞.人类活动与生态系统变化的前沿科学问题.北京:高等教育出版社,2009:1-543.
[17]Cheng S L,Fang H J,Yu G R,Zhu T H,Zheng J J.Foliar and soil15N natural abundances provide field evidence on nitrogen dynamics in temperate and boreal forest ecosystems.Plant and Soil,2010,337(1/2):285-297.
[18]Wang Z,Xu Z B,Li X,Peng D,Tan Z.The main forest types and their features of community structure in northern slope of Changbai Mountain.Forest Ecosystem Research,1980,(1):25-42.
[19]Amundson R,Baisden W T.Stable isotope tracers and mathematical models in soil organic matter studies//Sala O E,Jackson R B,Mooney H A,Howarth R W,eds.Methods in Ecosystem Science.New York:Springer,2000:117-137.
[20]Garten C T Jr,Cooper L W,Post W M III,Hanson P J.Climate controls on forest soil C isotope ratios in the southern Appalachian Mountains.Ecology,2000,81(4):1108-1119.
[21]Powers J S,Schlesinger W H.Geographic and vertical patterns of stable carbon isotopes in tropical rain forest soils of Costa Rica.Geoderma,2002,109(1/2):141-160.
[22]Chapin F S III,Matson P A,Vitousek P.Principles of Terrestrial Ecosystem Ecology.New York:Springer,2011:1-546.
[23]He J S,Fang J Y,Wang Z H,Guo D L,Flynn D F B,Geng Z.Stoichiometry and large-scale patterns of leaf carbon and nitrogen in the grassland biomes of China.Oecologia,2006,149(1):115-122.
[24]Bai Y F,Wu J G,Clark C M,Pan Q M,Zhang L X,Chen S P,Wang Q B,Han X G.Grazing alters ecosystem functioning and C:N:P stoichiometry of grasslands along a regional precipitation gradient.Journal of Applied Ecology,2012,49(6):1204-1215.
[25]Ripullone F,Lauteri M,Grassi G,Amato M,Borghetti M.Variation in nitrogen supply changes water-use efficiency of Pseudotsuga menziesii and Populus x euroamericana;a comparison of three approaches to determine water-use efficiency.Tree Physiology,2004,24(6):671-679.
[26]Yu G R,Song X,Wang Q F,Liu Y F,Guan D X,Yan J H,Sun X M,Zhang L M,Wen X F.Water-use efficiency of forest ecosystems in eastern China and its relations to climatic variables.New Phytologist,2008,177(4):927-937.
[27]Arai H,Tokuchi N.Factors contributing to greater soil organic carbon accumulation after afforestation in a Japanese coniferous plantation as determined by stable and radioactive isotopes.Geoderma,2010,157(3/4):243-251.
[28]黄昌勇,徐建明.土壤学(第三版).北京:中国农业出版社,2010:1-379.
[29]Zhang M,Zhang X K,Liang W J,Jiang Y,Dai G H,Wang X G,Han S J.Distribution of soil organic carbon fractions along the altitudinal gradient in Changbai Mountain,China.Pedosphere,2011,21(5):615-620.
[30]Blair G J,Lefroy R D B,Lisle L.Soil carbon fractions based on their degree of oxidation,and the development of a carbon management index for agricultural systems.Australian Journal of Agricultural Research,1995,46(7):1459-1466.
[31]Yang Y H,Mohammat A,Feng J M,Zhou R,Fang J Y.Storage,patterns and environmental controls of soil organic carbon in China.Biogeochemistry,2007,84(2):131-141.
[32]Ehleringer J R,Buchmann N,Flanagan L B.Carbon isotope ratios in belowground carbon cycle processes.Ecological Applications,2000,10(2):412-422.
[33]Liu W G,Feng X H,Ning Y F,Zhang Q L,Cao Y N,An Z S.δ13C variation of C3and C4plants across an Asian monsoon rainfall gradient in arid northwestern China.Global Change Biology,2005,11(7):1094-1100.
[34]于贵瑞,王绍强,陈泮勤,李庆康.碳同位素技术在土壤碳循环研究中的应用.地球科学进展,2005,20(5):568-577.
[35]Gao J Q,Lei G C,Zhang X W,Wang G X.Canδ13C abundance,water-soluble carbon,and light fraction carbon be potential indicators of soil organic carbon dynamics in Zoigêwetland?Catena,2014,119:21-27.