青藏高原北麓河流域不同退化程度高寒草甸土壤呼吸特征
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摘要
土壤呼吸是陆地生态系统碳循环的重要环节之一,而青藏高原高寒草甸的大面积退化对土壤呼吸及碳循环造成重要影响。为了进一步探明高寒草甸退化对土壤呼吸的影响,对北麓河区不同退化程度高寒草甸土壤呼吸及其相关因子进行了测定,分析了土壤呼吸与生物量、地下净初级生产力以及土壤温度的关系。结果表明:1)不同退化程度高寒草甸土壤呼吸在生长季均表现出相似的动态特征,随退化程度加剧呈先增加后降低的变化趋势,在中度退化程度达到最大值,且在生长季中期变化显著(P <0.05)。2)土壤呼吸和地上、地下生物量及地下净初级生产力均显著线性正相关(P <0.05)。3)土壤温度与土壤呼吸之间呈指数关系,但不同退化程度下土壤呼吸对土壤温度的敏感性不同,土壤呼吸敏感性在轻度退化(Q_(10)=3.26)和中度退化程度(Q_(10)=3.22)大于未退化(Q_(10)=2.66),而在重度退化(Q_(10)=2.49)和极度退化程度(Q_(10)=1.96)小于未退化;这主要是由不同退化程度土壤温度、地下生物量以及土壤有机碳含量的差异造成。研究的结果有助于进一步认识退化草地的碳循环过程。
Soil respiration is one of the most important components of the carbon cycle in terrestrial ecosystems. The widely distributed degradation of the alpine meadows on the Tibetan Plateau will impact the soil respiration and carbon cycle. In order to further explore the effects of degradation on the soil respiration of alpine meadows, we measured the soil respiration and related factors of alpine meadows under different levels of degradation in the Beiluhe area, and the relationships between soil respiration and biomass, belowground net primary productivity(BNPP) and soil temperature was analyzed. Our results showed that: 1) Soil respiration of alpine meadows at different levels of degradation showed similar dynamic characteristics during the growing season. Soil respiration increased first and then decreased along the degradation gradient, which reached the maximum under moderate degradation and significantly changed in the middle of the growing season(P < 0.05); 2)There was a significant positive linear correlation between the soil respiration and the aboveground biomass, belowground biomass, and BNPP(P < 0.05); 3) The soil respiration is exponentially correlated with the soil temperature. The temperature sensitivity of the soil respiration changed with the degradation. The Q_(10) under slight(Q_(10) = 3.26) and moderate degradation(Q_(10) = 3.22) was higher than that under non-degraded soils(Q_(10) = 2.66); however, under severe(Q10 = 2.49) and extreme degradation(Q_(10) = 1.96), this was lower than that under no degradation. The change in the temperature sensitivity is mainly caused by differences in the soil temperature, belowground biomass, and soil organic carbon content under different degradation levels. The results of this study will help further the understanding of the carbon cycle process of degraded grasslands.
Soil respiration is one of the most important components of the carbon cycle in terrestrial ecosystems. The widely distributed degradation of the alpine meadows on the Tibetan Plateau will impact the soil respiration and carbon cycle. In order to further explore the effects of degradation on the soil respiration of alpine meadows, we measured the soil respiration and related factors of alpine meadows under different levels of degradation in the Beiluhe area, and the relationships between soil respiration and biomass, belowground net primary productivity(BNPP) and soil temperature was analyzed. Our results showed that: 1) Soil respiration of alpine meadows at different levels of degradation showed similar dynamic characteristics during the growing season. Soil respiration increased first and then decreased along the degradation gradient, which reached the maximum under moderate degradation and significantly changed in the middle of the growing season(P < 0.05); 2)There was a significant positive linear correlation between the soil respiration and the aboveground biomass, belowground biomass, and BNPP(P < 0.05); 3) The soil respiration is exponentially correlated with the soil temperature. The temperature sensitivity of the soil respiration changed with the degradation. The Q_(10) under slight(Q_(10) = 3.26) and moderate degradation(Q_(10) = 3.22) was higher than that under non-degraded soils(Q_(10) = 2.66); however, under severe(Q10 = 2.49) and extreme degradation(Q_(10) = 1.96), this was lower than that under no degradation. The change in the temperature sensitivity is mainly caused by differences in the soil temperature, belowground biomass, and soil organic carbon content under different degradation levels. The results of this study will help further the understanding of the carbon cycle process of degraded grasslands.
引文
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[22]WANG J F,WANG G X,HU H C,WU Q B.The influence of degradation of the swamp and alpine meadows on CH4 and CO2fluxes on the Qinghai-Tibetan Plateau.Environmental Earth Sciences,2010,60(3):537-548.
[23]LI W,WANG J L,ZHANG X J,SHI S L,CAO W X.Effect of degradation and rebuilding of artificial grasslands on soil respiration and carbon and nitrogen pools on an alpine meadow of the Qinghai-Tibetan Plateau.Ecological Engineering,2018,111:134-142.
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[25]李虎,邱建军,王立刚.农田土壤呼吸特征及根呼吸贡献的模拟分析.农业工程学报,2008,24(4):14-20.LI H,QIU J J,WANG L G.Characterization of farmland soil respiration and modeling analysis of contribution of root respiration.Transactions of the Chinese Society of Agricultural Engineering,2008,24(4):14-20.
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[2]LUO Y Q,ZHOU X H.Soil Respiration and the Environment.San Diego,USA:Elsevier,2006.
[3]聂立凯,于政达,孔范龙,李悦,郗敏.土壤动物对土壤碳循环的影响研究进展.生态学杂志,2019,38(3):882-890.NIE L K,YU Z D,KONG F L,LI Y,XI M.Advancement in study on effects of soil fauna on soil carbon cycling.Chinese Journal of Ecology,2019,38(3):882-890.
[4]王家骏,王传宽,韩轶.帽儿山不同年龄森林土壤呼吸速率的影响因子.生态学报,2018,38(4):1194-1202.WANG J J,WANG C K,HAN Y.Factors affecting soil respiration in stands of different ages in the Maoershan region,Northeast China.Acta Ecologica Sinica,2018,38(4):1194-1202.
[5]尤全刚,薛娴,彭飞,董斯扬.高寒草甸草地退化对土壤水热性质的影响及其环境效应.中国沙漠,2015,35(5):1183-1192.YOU Q G,XUE X,PENG F,DONG S Y.Alpine meadow degradation effect on soil thermal and hydraulic properties and its environmental impacts.Journal of Desert Research,2015,35(5):1183-1192.
[6]李成阳,薛娴,赖炽敏,尤全刚,彭飞,张文娟.青藏高原退化高寒草甸生长季承载力.中国沙漠,2018,38(6):1330-1338.LI C Y,XUE X,LAI C M,YOU Q G,PENG F,ZHANG W J.Growing Season Bearing Capacity of Degraded Alpine Meadow in the Qinghai-Tibet Plateau.Journal of Desert Research,2018,38(6):1330-1338.
[7]徐翠,张林波,杜加强,郭杨,吴志丰,徐延达,李芬,王风玉.三江源区高寒草甸退化对土壤水源涵养功能的影响.生态学报,2013,33(8):2388-2399.XU C,ZHANG L B,DU J Q,GUO Y,WU Z F,XU Y D,LI F,WANG F Y.Impact of alpine meadow degradation on soil water conservation in the source region of three rivers.Acta Ecologica Sinica,2013,33(8):2388-2399.
[8]WANG G X,WANG Y B,LI Y S,CHENG H Y.Influences of alpine ecosystem responses to climatic change on soil properties on the Qinghai-Tibet Plateau,China.Catena,2007,70(3):506-514.
[9]周丽,张德罡,贠旭江,董永平,王加亭,赵雅丽.退化高寒草甸植被与土壤特征.草业科学,2016,33(11):2196-2201.ZHOU L,ZHANG D G,YUN X J,DONG Y P,WANG J T,ZHAO Y L.The vegetation and soil characteristics of degraded alpine meadow.Pratacultural Science,2016,33(11):2196-2201.
[10]HIROTA M,ZHANG P C,GU S,SHEN H H,KURIYAMA T,LI Y N,TANG Y H.Small-scale variation in ecosystem CO2 fluxes in an alpine meadow depends on plant biomass and species richness.Journal of Plant Research,2010,123(4):531-541.
[11]NAEEM S,THOMPSON L J,LAWLER S P,LAWTON J H,WOODFIN R M.Declining biodiversity can alter the performance of ecosystems.Nature,1994,368(6473):734-737.
[12]刘淑丽,林丽,张法伟,杜岩功,李以康,郭小伟,欧阳经政,曹广民.放牧季节及退化程度对高寒草甸土壤有机碳的影响.草业科学,2016,33(1):11-18.LIU S L,LIN L,ZHANG F W,DU Y G,LI Y K,GUO X W,OUYANG J Z,CAO G M.Effects of grazing season and degradation degree on the soil organic carbon in alpine meadow.Pratacultural Science,2016,33(1):11-18.
[13]NI J.Carbon storage in grasslands of China.Journal of Arid Environments,2002,50(2):0-218.
[14]裴志永,欧阳华,周才平.青藏高原高寒草原碳排放及其迁移过程研究.生态学报,2001,23(2):231-236.PEI Z Y,OUYANG H,ZHOU C P.A study on carbon fluxes from alpine grassland ecosystem on Tibetan Plateau.Acta Ecologica Sinica,2001,23(2):231-236.
[15]WANG J F,WU Q B.Impact of experimental warming on soil temperature and moisture of the shallow active layer of wet meadows on the Qinghai-Tibet Plateau.Cold Regions Science and Technology,2013,90-91:1-8.
[16]温军,周华坤,姚步青,李以康,赵新全,陈哲,连利叶,郭凯先.三江源区不同退化程度高寒草原土壤呼吸特征.植物生态学报,2014,38(2):209-218.WEN J,ZHOU H K,YAO Q B,LI Y K,ZHAO X Q,CHEN Z,LIAN L Y,GUO K X.Characteristics of soil respiration in different degraded alpine grassland in the source region of Three-River.Chinese Journal of Plant Ecology,2014,38(2):209-218.
[17]PENG F,YOU Q G,XUE X,GUO J,WANG T.Effects of rodent-induced land degradation on ecosystem carbon fluxes in an alpine meadow in the Qinghai-Tibet Plateau,China.Solid Earth,2015,6:301-310.
[18]WU Q B,LIU Y Z.Ground temperature monitoring and its recent change in Qinghai-Tibet Plateau.Cold Regions Science&Technology,2004,38(2):85-92.
[19]薛娴,郭坚,张芳,宗莉,韩邦帅,黄翠华.高寒草甸地区沙漠化发展过程及成因分析:以黄河源区玛多县为例.中国沙漠,2007,27(5):725-732.XUE X,GUO J,ZHANG F,ZONG L,HAN B S,HUANG C H.Development and cause of aeolian desertification in Alpine Region:In case of Maduo County in Yellow River Source Area.Journal of Desert Research,2007,27(5):725-732.
[20]WALKLEY A.A critical examination of a rapid method for determining organic carbon in soils-effect of variations in digestion conditions and of inorganic soil constituents.Soil Science,1947,63:251-264.
[21]任继周.草业科学研究方法.北京:中国农业出版社,1998:152-158.REN J Z.Research methods of Grassland Science.Beijing:China Agriculture Press,1998:152-158.
[22]WANG J F,WANG G X,HU H C,WU Q B.The influence of degradation of the swamp and alpine meadows on CH4 and CO2fluxes on the Qinghai-Tibetan Plateau.Environmental Earth Sciences,2010,60(3):537-548.
[23]LI W,WANG J L,ZHANG X J,SHI S L,CAO W X.Effect of degradation and rebuilding of artificial grasslands on soil respiration and carbon and nitrogen pools on an alpine meadow of the Qinghai-Tibetan Plateau.Ecological Engineering,2018,111:134-142.
[24]田林卫,周华坤,刘泽华,魏晴,姚步青,王文颖,赵新全.高寒草甸区不同生境土壤呼吸变化规律及其与水热因子的关系.草业科学,2014,31(7):1233-1240.TIAN L W,ZHOU H K,LIU Z H,WEI Q,YAO B Q,WANG W Y,ZHAO X Q.Soil respiration variation and its relationship with hydrothermic factor under different biotopes of alpine meadow distributed area.Pratacultural Science,2014,31(7):1233-1240.
[25]李虎,邱建军,王立刚.农田土壤呼吸特征及根呼吸贡献的模拟分析.农业工程学报,2008,24(4):14-20.LI H,QIU J J,WANG L G.Characterization of farmland soil respiration and modeling analysis of contribution of root respiration.Transactions of the Chinese Society of Agricultural Engineering,2008,24(4):14-20.
[26]GIARDINA C P,RYAN M G.Evidence that decomposition rates of organic carbon in mineral soil do not vary with temperature.Nature,2000,404(6780):858-861.
[27]REY A,PEGORARO E,OYONARTE C,WERE A,ESCRIBANO P,RAIMUNDO J.Impact of land degradation on soil respiration in a steppe(Stipa tenacissima L.)semi-arid ecosystem in the SE of Spain.Soil Biology&Biochemistry,2011,43(2):393-403.
[28]DAVIDSON E,JANSSENS I.Temperature sensitivity of soil carbon decomposition and feedbacks to climate change.Nature,2006,440:165-169.
[29]HANSON P J,O’NEILL E G,CHAMBERS M L S,RIGGS J S,JOSLIN J D,WOLFE M H.Soil respiration and litter decomposition.//North american temperate deciduous forest responses to changing precipitation regimes.New York,USA:Springer,2003,166:163-189.
[30]BOND-LAMBERTY B,THOMSON A.Temperature-associated increase in the global soil respiration record.Nature,2010,464:579-583.
[31]LIU W J,CHEN S,ZHAO Q,SUN Z Z,REN J W,QIN D H.Variation and control of soil organic carbon and other nutrients in permafrost regions on central Qinghai-Tibetan Plateau.Environmental Research Letters,2014,9(11):114013.
[32]PENG F,XUE X,YOU Q G,HUANG C H,DONG S Y,LIAO J,DUAN H C,ATSUSHI T,WANG T.Changes of soil properties regulate the soil organic carbon loss with grassland degradation on the Qinghai-Tibet Plateau.Ecological Indicators,2018,93:572-580.
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