Steady state turnover time of carbon in the Australian terrestrial biosphere

被引:101
作者
Barrett, DJ [1 ]
机构
[1] CSIRO Plant Ind, Canberra, ACT 2601, Australia
关键词
terrestrial carbon cycle; mean residence time; model parameterization; genetic algorithm;
D O I
10.1029/2002GB001860
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
[1] The turnover time of terrestrial carbon was estimated using a multiobjective parameterization method that combined data sets of plant production, biomass, litter and soil-C observations in the calibration of a C-cycle model for the Australian continent (VAST1.1; Vegetation and Soil carbon Transfer). The method employed a genetic algorithm to minimize model-data deviations and maximize consistency between estimated model parameters and all available data. Based on the parameterization, the turnover time of biosphere C for Australia was estimated to be 78 years which is longer than global C-turnover estimates (of 26-60 years) due entirely to slower turnover of C in the upper 20 cm of soil. Turnover times of litter and deeper soil-C were similar to global values. By splitting total C in the upper 20 cm between labile and nonlabile fractions (based on published data) the turnover time of the labile pool was at least 44 years which is still longer than global estimates (9-25 years). Longer C-turnover in Australian surface soils was attributed to (1) limited soil moisture slowing decomposition more than net primary production, (2) frequent fires leading to a large fraction of nonlabile charcoal C in soil, and (3) strong adsorbing capacity for organic-C in these highly weathered soils. It was found that >89% of the C flux to the atmosphere from decomposition of organic matter originated from fine litter, coarse woody debris and the upper 20 cm of soil in all biomes.
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页数:21
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共 142 条
  • [1] [AUSLIG] Australian Surveying and Land Information Group, 1990, ATL AUSTR RES, V6
  • [2] Quantifying uncertainty in estimates of C emissions from above-ground biomass due to historic land-use change to cropping in Australia
    Barrett, DJ
    Galbally, IE
    Graetz, RD
    [J]. GLOBAL CHANGE BIOLOGY, 2001, 7 (08) : 883 - 902
  • [3] BARRETT DJ, 2001, MULTIBIOME VAST CALI
  • [4] BARRETT DJ, 1992, THESIS AUST NATL U C
  • [5] Modeling vertical distribution of carbon in oxisols of the western Brazilian Amazon (Rondonia)
    Bernoux, M
    Arrouays, D
    Cerri, CC
    Bourennane, H
    [J]. SOIL SCIENCE, 1998, 163 (12) : 941 - 951
  • [6] Bevington P., 2002, Data Reduction and Error Analysis for the Physical Sciences, V3rd ed.
  • [7] A latitudinal gradient in carbon turnover times in forest soils
    Bird, MI
    Chivas, AR
    Head, J
    [J]. NATURE, 1996, 381 (6578) : 143 - 146
  • [8] Bolker BM, 1998, ECOL APPL, V8, P425, DOI 10.1890/1051-0761(1998)008[0425:LAOSDI]2.0.CO
  • [9] 2
  • [10] THE STORAGE AND PRODUCTION OF ORGANIC-MATTER IN TROPICAL FORESTS AND THEIR ROLE IN THE GLOBAL CARBON-CYCLE
    BROWN, S
    LUGO, AE
    [J]. BIOTROPICA, 1982, 14 (03) : 161 - 187