Complexity, climate change and soil carbon: A systems approach to microbial temperature response

A proliferation of data gathered to predict a critically important, urgent and social-policy related question often leads to debate and divergent model results. This classic feature of complex systems is currently being evidenced in assessing a potentially serious feedback response of soil respiration with increased temperatures due to global climate change. Here we apply soft systems modelling (SSM) for a detailed analysis of the ‘‘soft’’ aspects of the topic. Supported by a literature review, we conclude that that varied perspectives on the system’s dynamics and its web of controlling factors have led to seemingly conflicting results. We present a simplified hierarchy organizing the comprehensive universe of interacting controls across scales. This model is implemented as a relational database, including relationships between factors such as nesting and feedbacks. We conclude that although this model is currently limited to pairwise interactions, it provides a useful tool to assess potential interactions and factors of interest. Copyright # 2009 John Wiley & Sons, Ltd.

[1]  K. Boulding,et al.  Value Systems and Social Process. , 1971 .

[2]  James B. Grace,et al.  Structural Equation Modeling and Natural Systems , 2006 .

[3]  Peter Checkland,et al.  Soft Systems Methodology in Action , 1990 .

[4]  Michael G. Ryan,et al.  Below-ground process responses to elevated CO2 and temperature: a discussion of observations, measurement methods, and models , 2004 .

[5]  J. E. Hunt,et al.  Commentary: Carbon Metabolism of the Terrestrial Biosphere: A Multitechnique Approach for Improved Understanding , 2000, Ecosystems.

[6]  T. Müller,et al.  Soil organic matter turnover as a function of the soil clay content: consequences for model applications , 2004 .

[7]  Mary K. Firestone,et al.  Linking microbial community composition and soil processes in a California annual grassland and mixed-conifer forest , 2005 .

[8]  D. Sylvia.  Principles and Applications of Soil Microbiology , 1997 .

[9]  S. Allison,et al.  Resistance, resilience, and redundancy in microbial communities , 2008, Proceedings of the National Academy of Sciences.

[10]  M. Kirschbaum.  The temperature dependence of organic-matter decomposition - still a topic of debate , 2006 .

[11]  W. Oechel,et al.  Microbial activity in soils frozen to below −39 °C , 2006 .

[12]  A. Dobermann,et al.  Soil electrical conductivity and water content affect nitrous oxide and carbon dioxide emissions in intensively managed soils. , 2006, Journal of environmental quality.

[13]  M. Kirschbaum,et al.  Will changes in soil organic carbon act as a positive or negative feedback on global warming? , 2000 .

[14]  M. McInerney,et al.  Temperature, wetting cycles and soil texture effects on carbon and nitrogen dynamics in stabilized earthworm casts. , 2000 .

[15]  S. Martin,et al.  “Redesigning the future” , 1987, Journal of General Internal Medicine.

[16]  R. Miller,et al.  Using landscape and depth gradients to decouple the impact of correlated environmental variables on soil microbial community composition , 2007 .

[17]  Keith A. Smith,et al.  Exchange of greenhouse gases between soil and atmosphere: interactions of soil physical factors and biological processes , 2003 .

[18]  V. Bailey,et al.  Relationships between soil microbial biomass determined by chloroform fumigation–extraction, substrate-induced respiration, and phospholipid fatty acid analysis , 2002 .

[19]  L. Weihermüller,et al.  Measurement depth effects on the apparent temperature sensitivity of soil respiration in field studies , 2008 .

[20]  T. Allen,et al.  Hierarchy Theory: A Vision, Vocabulary, and Epistemology , 1996 .

[21]  C. S. Holling.  Understanding the Complexity of Economic, Ecological, and Social Systems , 2001, Ecosystems.

[22]  T. Addiscott,et al.  Mineralization of native soil organic matter is not regulated by the size, activity or composition of the soil microbial biomass-a new perspective , 2008 .

[23]  Y. Kuzyakov,et al.  Root and rhizomicrobial respiration: A review of approaches to estimate respiration by autotrophic and heterotrophic organisms in soil , 2005 .

[24]  M. G. Ryan,et al.  The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review. , 2007, The New phytologist.

[25]  Jiří Hřebíček,et al.  Soft Systems Methodology Applied to Environmental Modeling , 2003 .

[26]  David L. Jones,et al.  Root exudate components change litter decomposition in a simulated rhizosphere depending on temperature , 2006, Plant and Soil.

[27]  Lutz Weihermüller,et al.  Sensitivity of simulated soil heterotrophic respiration to temperature and moisture reduction functions , 2008 .

[28]  Peter Checkland,et al.  Systems Thinking, Systems Practice , 1981 .

[29]  M. Firestone,et al.  Response of Microbial Community Composition and Function to Soil Climate Change , 2006, Microbial Ecology.

[30]  J. Tenhunen,et al.  Does the temperature sensitivity of decomposition of soil organic matter depend upon water content, soil horizon, or incubation time? , 2005 .

[31]  Tom Addiscott,et al.  Modeling for All Scales: An Introduction to System Simulation , 2001 .

[32]  G. Ågren,et al.  Analysing temperature response of decomposition of organic matter , 2005 .

[33]  S. Gower.  Patterns and Mechanisms of the Forest Carbon Cycle1 , 2003 .

[34]  R. Cully,et al.  Recalcitrant soil organic materials mineralize more efficiently at higher temperatures , 2003 .

[35]  Mycorrhizas and global environmental change: research at different scales , 2002 .

[36]  Eric A. Davidson,et al.  On the variability of respiration in terrestrial ecosystems: moving beyond Q 10 , 2006 .

[37]  T. Balser,et al.  Microbial stress-response physiology and its implications for ecosystem function. , 2007, Ecology.

[38]  Michael J. Rogers,et al.  Long-term sensitivity of soil carbon turnover to warming , 2005, Nature.

[39]  M. Reichstein,et al.  Colimitation of decomposition by substrate and decomposers - a comparison of model formulations , 2008 .

[40]  Bruno Mary,et al.  Modelling temperature and moisture effects on C-N transformations in soils: comparison of nine models , 1997 .

[41]  Arthur Koestler,et al.  Beyond Atomism and Holism—the Concept of the Holon , 2015 .

[42]  J. Handelsman.  Metagenomics: Application of Genomics to Uncultured Microorganisms , 2004, Microbiology and Molecular Biology Reviews.

[43]  R. M. Goodman,et al.  Microbial response over time to hydrologic and fertilization treatments in a simulated wet prairie , 2006, Plant and Soil.

[44]  P. Jarvis,et al.  Modelling the effect of temperature on carbon mineralization rates across a network of European forest sites (FORCAST) , 2006 .

[45]  R. C. Izaurralde,et al.  Long-term modeling of soil C erosion and sequestration at the small watershed scale , 2007 .

[46]  Yiqi Luo,et al.  Acclimatization of soil respiration to warming in a tall grass prairie , 2001, Nature.

[47]  G. Ågren,et al.  Soil organic matter quality interpreted thermodynamically , 1999 .

[48]  Alan E. Waring,et al.  Practical Systems Thinking , 1996 .

[49]  William K. Lauenroth,et al.  Models in Ecosystem Science , 2003, Models in Ecosystem Science.

[50]  T. Balser,et al.  Investigating biological control over soil carbon temperature sensitivity , 2009 .

[51]  C. Alewell,et al.  Warming mineralises young and old soil carbon equally , 2006 .

[52]  Mario Giampietro,et al.  Multi-Scale Integrated Analysis of Agroecosystems , 2003 .

[53]  T. Allen,et al.  Toward a Unified Ecology. , 1994 .

[54]  C. Jacobsen,et al.  Spatial complexity of soil organic matter forms at nanometre scales , 2008 .

[55]  W. Ulrich,et al.  Beyond methodology choice: critical systems thinking as critically systemic discourse , 2003, J. Oper. Res. Soc..

[56]  D. Mummey,et al.  Analysis of Soil Whole- and Inner-Microaggregate Bacterial Communities , 2004, Microbial Ecology.

[57]  E. Pendall,et al.  Rhizodeposition stimulated by elevated CO2 in a semiarid grassland , 2004 .

[58]  G. Ågren,et al.  What determines the temperature response of soil organic matter decomposition , 2007 .

[59]  D. R. Bowling,et al.  Integration of Process-based Soil Respiration Models with Whole-Ecosystem CO2 Measurements , 2008, Ecosystems.

[60]  T. F. H. Allen,et al.  The importance of scale in evaluating herbivory impacts , 1989 .

[61]  John Moncrieff,et al.  Impact of Global Warming on Soil Organic Carbon , 2008 .

[62]  Yanhong Tang,et al.  Storage, patterns and controls of soil organic carbon in the Tibetan grasslands , 2008 .

[63]  A. Kinzig,et al.  Linking Soil Microbial Communities and Ecosystem Functioning , 2002 .

[64]  K. Ekschmitt,et al.  Stabilization of organic matter in temperate soils: mechanisms and their relevance under different soil conditions – a review , 2006 .

[65]  A. Porporato,et al.  A theoretical analysis of nonlinearities and feedbacks in soil carbon and nitrogen cycles , 2007 .

[66]  E. Davidson,et al.  Temperature sensitivity of soil carbon decomposition and feedbacks to climate change , 2006, Nature.

[67]  L. Gu,et al.  Fast labile carbon turnover obscures sensitivity of heterotrophic respiration from soil to temperature: A model analysis , 2004 .

[68]  R. O'Neill.  A Hierarchical Concept of Ecosystems. , 1986 .

[69]  T. Balser,et al.  Elevated CO2 differentially alters belowground plant and soil microbial community structure in reed canary grass-invaded experimental wetlands , 2007 .

[70]  A. Kowalski,et al.  Can flux tower research neglect geochemical **CO2** exchange? , 2008 .

[71]  N. Panikov.  Understanding and prediction of soil microbial community dynamics under global change , 1999 .

[72]  K. McMahon,et al.  Bridging the gap between micro - and macro-scale perspectives on the role of microbial communities in global change ecology , 2006, Plant and Soil.

[73]  J. Wiens.  Spatial Scaling in Ecology , 1989 .

[74]  F Stuart Chapin,et al.  Effects of plant traits on ecosystem and regional processes: a conceptual framework for predicting the consequences of global change. , 2003, Annals of botany.

[75]  V. Torsvik,et al.  High diversity in DNA of soil bacteria , 1990, Applied and environmental microbiology.

[76]  J. Megonigal,et al.  An oxygen‐mediated positive feedback between elevated carbon dioxide and soil organic matter decomposition in a simulated anaerobic wetland , 2007 .

[77]  M. Kirschbaum.  Soil respiration under prolonged soil warming: are rate reductions caused by acclimation or substrate loss? , 2004 .

[78]  S. Trumbore.  Carbon respired by terrestrial ecosystems – recent progress and challenges , 2006 .

[79]  B. Ellert,et al.  Temperature dependence of net nitrogen and sulfur mineralization , 1992 .

[80]  E. Davidson,et al.  Vertical partitioning of CO2 production within a temperate forest soil , 2006 .

[81]  Charles T. Garten,et al.  Separating root and soil microbial contributions to soil respiration: A review of methods and observations , 2000 .