Partitioning Sources of Ecosystem and Soil Respiration in an Alpine Meadow of Tibet Plateau Using Regression Method

ABSTRACT: Partitioning sourćes of ecosystem and soil respiration (R eco and Rs) is important for understanding how climate change affects carbon cycling. Plant and microbial biomass analyses and daytime measurements of Reco and Rs were performed for 25 plots in an alpine meadow at elevation 4313 m on the Tibetan Plateau. Plant and microbial biomass were determined by harvesting method and the chloroform fumigation-extraction method, respectively. Respiration fluxes were measured by an automated CO2 flux system (LI-8100, LI-COR Biosciences, Lincoln, NE, USA). Soil respiration can be estimated by a linear or exponential relationship between Reco and aboveground plant biomass (AGB). Microbial respiration (Rm) can be estimated by a linear or exponential relationship between Rs and belowground plant biomass (BGB) or by a multiple relationship between Reco and AGB and BGB. Soil respiration (or Rm) is respiration flux when AGB (or BGB) is extrapolated to zero for the linear and exponential regression methods. Similarly, Rm is respiration flux when both AGB and BGB are zero for the multiple regression method. Our findings suggest that the exponential regression method to partition sources of Reco and R s may be more appropriate compared to other methods for this alpine meadow of Tibet.

[1]  Yakov Kuzyakov,et al.  Sources of CO2 efflux from soil and review of partitioning methods , 2006 .

[2]  P. Brookes,et al.  AN EXTRACTION METHOD FOR MEASURING SOIL MICROBIAL BIOMASS C , 1987 .

[3]  M. Liebig,et al.  Management effects on soil CO2 efflux in northern semiarid grassland and cropland , 2006 .

[4]  Guirui Yu,et al.  Net ecosystem CO2 exchange and controlling factors in a steppe—Kobresia meadow on the Tibetan Plateau , 2006 .

[5]  J. Welker,et al.  CO2 exchange in three Canadian High Arctic ecosystems: response to long‐term experimental warming , 2004 .

[6]  Shucun Sun,et al.  Plant clipping may cause overestimation of soil respiration in a Tibetan alpine meadow, southwest China , 2011, Ecological Research.

[7]  Xianzhou Zhang,et al.  Response of ecosystem respiration to experimental warming and clipping at daily time scale in an alpine meadow of tibet , 2013, Journal of Mountain Science.

[8]  Gang Fu,et al.  Response of soil microbial biomass to short-term experimental warming in alpine meadow on the Tibetan Plateau , 2012 .

[9]  R. Hatano,et al.  Variation of Soil Respiration from Different Land Uses in Subtropical Agricultural Soils, Central China , 2010, 2010 4th International Conference on Bioinformatics and Biomedical Engineering.

[10]  M. Bahn,et al.  Root respiration in temperate mountain grasslands differing in land use , 2006 .

[11]  C. Kucera,et al.  Soil Respiration Studies in Tallgrass Prairie in Missouri , 1971 .

[12]  J. Iqbal,et al.  Microbial biomass, and dissolved organic carbon and nitrogen strongly affect soil respiration in different land uses: A case study at Three Gorges Reservoir Area, South China , 2010 .

[13]  Dong Li,et al.  Growing season ecosystem respirations and associated component fluxes in two alpine meadows on the Tibetan Plateau. , 2008, Journal of integrative plant biology.

[14]  Wei Sun,et al.  Calibration of MODIS-based gross primary production over an alpine meadow on the Tibetan Plateau , 2012 .

[15]  Yang-jian Zhang,et al.  Response of microbial biomass to grazing in an alpine meadow along an elevation gradient on the Tibetan Plateau , 2012 .

[16]  Guangqiang Luo,et al.  Influencing factors and partitioning of respiration in a Leymus chinensis steppe in Xilin River Basin, Inner Mongolia, China , 2011 .

[17]  Edward A G Schuur,et al.  Thawing permafrost increases old soil and autotrophic respiration in tundra: Partitioning ecosystem respiration using δ13C and ∆14C , 2013, Global change biology.

[18]  B. Hungate,et al.  Responses of Ecosystem Carbon Cycling to Climate Change Treatments Along an Elevation Gradient , 2011, Ecosystems.

[19]  Yanhong Tang,et al.  Use of a regression method to partition sources of ecosystem respiration in an alpine meadow , 2009 .

[20]  Geng Yuan-bo,et al.  Influencing factors and partitioning of respiration in a Leymus chinensis steppe in Xilin River Basin,Inner Mongolia,China , 2011 .

[21]  N. Krishnayya,et al.  Soil organic carbon dynamics in two functional types of ground cover ( grasses and herbaceous ) in the tropics , 2011 .

[22]  M. Symonds,et al.  A brief guide to model selection, multimodel inference and model averaging in behavioural ecology using Akaike’s information criterion , 2010, Behavioral Ecology and Sociobiology.

[23]  Yuting Zhou,et al.  Experimental warming does not enhance gross primary production and above-ground biomass in the alpine meadow of Tibet , 2013 .

[24]  Steven F. Oberbauer,et al.  TUNDRA CO2 FLUXES IN RESPONSE TO EXPERIMENTAL WARMING ACROSS LATITUDINAL AND MOISTURE GRADIENTS , 2007 .