Influence of carbon‐nitrogen cycle coupling on land model response to CO2 fertilization and climate variability

[1] Nutrient cycling affects carbon uptake by the terrestrial biosphere and imposes controls on carbon cycle response to variation in temperature and precipitation, but nutrient cycling is ignored in most global coupled models of the carbon cycle and climate system. We demonstrate here that the inclusion of nutrient cycle dynamics, specifically the close coupling between carbon and nitrogen cycles, in a terrestrial biogeochemistry component of a global coupled climate system model leads to fundamentally altered behavior for several of the most critical feedback mechanisms operating between the land biosphere and the global climate system. Carbon-nitrogen cycle coupling reduces the simulated global terrestrial carbon uptake response to increasing atmospheric CO2 concentration by 74%, relative to a carbon-only counterpart model. Global integrated responses of net land carbon exchange to variation in temperature and precipitation are significantly damped by carbon-nitrogen cycle coupling. The carbon cycle responses to temperature and precipitation variation are reduced in magnitude as atmospheric CO2 concentration rises for the coupled carbon-nitrogen model, but increase in magnitude for the carbon-only counterpart. Our results suggest that previous carbon-only treatments of climate-carbon cycle coupling likely overestimate the terrestrial biosphere's capacity to ameliorate atmospheric CO2 increases through direct fertilization. The next generation of coupled climate-biogeochemistry model projections for future atmospheric CO2 concentration and climate change should include explicit, prognostic treatment of terrestrial carbon-nitrogen cycle coupling.

[1]  Gordon B. Bonan,et al.  Carbon and nitrogen cycling in North American boreal forests. II. Biogeographic patterns , 1990 .

[2]  Gordon B. Bonan,et al.  Evaluating Aspects of the Community Land and Atmosphere Models (CLM3 and CAM3) Using a Dynamic Global Vegetation Model , 2006 .

[3]  W. Cropper,et al.  Litterfall, Decomposition, and Nitrogen and Phosphorus Dynamics in a Chronosequence of Slash Pine (Pinus elliottii) Plantations , 1985 .

[4]  Taro Takahashi,et al.  Constraints on the Global Atmospheric CO 2 Budget , 2007 .

[5]  R. Schnur,et al.  Climate-carbon cycle feedback analysis: Results from the C , 2006 .

[6]  Ben Bond-Lamberty,et al.  Reimplementation of the Biome-BGC model to simulate successional change. , 2005, Tree physiology.

[7]  Robert W. Howarth,et al.  Nitrogen limitation on land and in the sea: How can it occur? , 1991 .

[8]  R. Mitchell,et al.  Effects of atmospheric CO(2) on longleaf pine: productivity and allocation as influenced by nitrogen and water. , 1997, Tree physiology.

[9]  Corinne Le Quéré,et al.  Regional changes in carbon dioxide fluxes of land and oceans since 1980. , 2000, Science.

[10]  R. F. Castillo,et al.  Soil Changes During Secondary Succession in a Tropical Montane Cloud Forest Area , 2005 .

[11]  H. G. Miller.  Carbon x nutrient interactions-the limitations to productivity. , 1986, Tree physiology.

[12]  P. Ciais,et al.  Europe-wide reduction in primary productivity caused by the heat and drought in 2003 , 2005, Nature.

[13]  G. Asner,et al.  Dissolved Organic Carbon in Terrestrial Ecosystems: Synthesis and a Model , 2001, Ecosystems.

[14]  Scott C. Doney,et al.  Natural Variability in a Stable, 1000-Yr Global Coupled Climate–Carbon Cycle Simulation , 2006 .

[15]  I. C. Prentice,et al.  Carbon balance of the terrestrial biosphere in the Twentieth Century: Analyses of CO2, climate and land use effects with four process‐based ecosystem models , 2001 .

[16]  Terry Koen,et al.  Restoring ecological function in temperate grassy woodlands: manipulating soil nutrients, exotic annuals and native perennial grasses through carbon supplements and spring burns , 2005 .

[17]  Edward B. Rastetter,et al.  RESPONSES OF N‐LIMITED ECOSYSTEMS TO INCREASED CO2: A BALANCED‐NUTRITION, COUPLED‐ELEMENT‐CYCLES MODEL , 1997 .

[18]  S. Sitch,et al.  The role of fire disturbance for global vegetation dynamics: coupling fire into a Dynamic Global Vegetation Model , 2008 .

[19]  Benjamin P Colman,et al.  Decadal-scale fates of 15N tracers added to oak and pine stands under ambient and elevated N inputs at the Harvard Forest (USA) , 2004 .

[20]  J. Lamarque,et al.  A global simulation of tropospheric ozone and related tracers: Description and evaluation of MOZART, version 2 , 2001 .

[21]  J. Six,et al.  Element interactions limit soil carbon storage. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[22]  Klaus Butterbach-Bahl,et al.  Carbon Sequestration in Arable Soils is Likely to Increase Nitrous Oxide Emissions, Offsetting Reductions in Climate Radiative Forcing , 2005 .

[23]  W. Collins,et al.  The Community Climate System Model Version 3 (CCSM3) , 2006 .

[24]  Peter E. Thornton,et al.  Assessing future nitrogen deposition and carbon cycle feedback using a multimodel approach: Analysis of nitrogen deposition , 2005 .

[25]  Peter E. Thornton,et al.  A diagnostic carbon flux model to monitor the effects of disturbance and interannual variation in climate on regional NEP , 2006 .

[26]  J. Houghton,et al.  Climate change 2001 : the scientific basis , 2001 .

[27]  P. Vitousek,et al.  The Influence of Nutrient Availability on Soil Organic Matter Turnover Estimated by Incubations and Radiocarbon Modeling , 2005, Ecosystems.

[28]  Harald Bugmann,et al.  EXPLAINING FOREST COMPOSITION AND BIOMASS ACROSS MULTIPLE BIOGEOGRAPHICAL REGIONS , 2000 .

[29]  Peter E. Thornton,et al.  Technical Description of the Community Land Model (CLM) , 2004 .

[30]  I. Fung,et al.  Observational Contrains on the Global Atmospheric Co2 Budget , 1990, Science.

[31]  E. Schuur,et al.  Nutrient cycling and plant–soil feedbacks along a precipitation gradient in lowland Panama , 2005, Journal of Tropical Ecology.

[32]  B. Law,et al.  Changes in carbon storage and fluxes in a chronosequence of ponderosa pine , 2003 .

[33]  J. Lamarque,et al.  Nitrogen and sulfur deposition on regional and global scales: A multimodel evaluation , 2006 .

[34]  Peter E. Thornton,et al.  Modeling and measuring the effects of disturbance history and climate on carbon and water budgets in evergreen needleleaf forests , 2002 .

[35]  R. Dickinson,et al.  The Community Land Model and Its Climate Statistics as a Component of the Community Climate System Model , 2006 .

[36]  N. Grimm,et al.  Towards an ecological understanding of biological nitrogen fixation , 2002 .

[37]  Christopher B. Field,et al.  Nitrogen and Climate Change , 2003, Science.

[38]  P. Thornton,et al.  Ecosystem model spin-up: Estimating steady state conditions in a coupled terrestrial carbon and nitrogen cycle model , 2005 .

[39]  Stan D. Wullschleger,et al.  Biochemical Limitations to Carbon Assimilation in C3 Plants—A Retrospective Analysis of the A/Ci Curves from 109 Species , 1993 .

[40]  R. Ceulemans,et al.  Forest response to elevated CO2 is conserved across a broad range of productivity. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[41]  Christopher B. Field,et al.  RESPONSES OF TERRESTRIAL ECOSYSTEMS TO THE CHANGING ATMOSPHERE: A Resource-Based Approach*'** , 1992 .

[42]  Peter E. Thornton,et al.  An Improved Canopy Integration Scheme for a Land Surface Model with Prognostic Canopy Structure , 2007 .

[43]  Peter E. Thornton,et al.  Regional ecosystem simulation: Combining surface- and satellite-based observations to study linkages between terrestrial energy and mass budgets , 1998 .

[44]  G. Meehl,et al.  The Importance of Land-Cover Change in Simulating Future Climates , 2005, Science.

[45]  P. Reich,et al.  Nitrogen limitation constrains sustainability of ecosystem response to CO2 , 2006, Nature.

[46]  F. Stuart Chapin,et al.  The Nature of Nutrient Limitation in Plant Communities , 1986, The American Naturalist.

[47]  John Pastor,et al.  Response of northern forests to CO2-induced climate change , 1988, Nature.

[48]  Edward B. Rastetter,et al.  A general biogeochemical model describing the responses of the C and N cycles in terrestrial ecosystems to changes in CO(2), climate, and N deposition. , 1991, Tree physiology.

[49]  A. McGuire,et al.  Interactions between carbon and nitrogen dynamics in estimating net primary productivity for potential vegetation in North America , 1992 .

[50]  Jean-Francois Lamarque,et al.  Variations in the predicted spatial distribution of atmospheric nitrogen deposition and their impact on carbon uptake by terrestrial ecosystems , 1997 .

[51]  P. Cox,et al.  How positive is the feedback between climate change and the carbon cycle? , 2003 .

[52]  K. Lindsay,et al.  Evolution of carbon sinks in a changing climate. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[53]  D. Schimel,et al.  CONTINENTAL SCALE VARIABILITY IN ECOSYSTEM PROCESSES: MODELS, DATA, AND THE ROLE OF DISTURBANCE , 1997 .

[54]  P. Fabian,et al.  Biomass Burning in the Amazon-Fertilizer for the Mountaineous Rain Forest in Ecuador (7 pp) , 2005, Environmental science and pollution research international.

[55]  G. Likens,et al.  Nutrient Release From Decomposing Leaf and Branch Litter in the Hubbard Brook Forest, New Hampshire , 1973 .

[56]  Yiqi Luo,et al.  Elevated CO2 stimulates net accumulations of carbon and nitrogen in land ecosystems: a meta-analysis. , 2006, Ecology.

[57]  D. Moorhead,et al.  A conceptual model for primary productivity, decomposition and nitrogen cycling in the Chihuahuan creosotebush desert. , 1986, Tree physiology.

[58]  J. Dufresne,et al.  On the magnitude of positive feedback between future climate change and the carbon cycle , 2002 .

[59]  R. B. Jackson,et al.  Potential nitrogen constraints on soil carbon sequestration under low and elevated atmospheric CO2. , 2006, Ecology.

[60]  W. G. Strand,et al.  Parallel climate model (PCM) control and transient simulations , 2000 .

[61]  J. William Munger,et al.  Exchange of Carbon Dioxide by a Deciduous Forest: Response to Interannual Climate Variability , 1996, Science.

[62]  M. Ret,et al.  Vegetation responses in Alaskan arctic tundra after 8 years of a summer warming and winter snow manipulation experiment , 2005 .

[63]  B. Law,et al.  Archiving numerical models of biogeochemical dynamics , 2005 .

[64]  B. Hungate,et al.  Nitrogen cycling during seven years of atmospheric CO2 enrichment in a scrub oak woodland. , 2006, Ecology.

[65]  R. Betts.  Integrated approaches to climate-crop modelling: needs and challenges. , 2005, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[66]  B. Emmett,et al.  Nitrogen deposition makes a minor contribution to carbon sequestration in temperate forests , 1999, Nature.

[67]  W. Parton,et al.  Progressive Nitrogen Limitation of Ecosystem Responses to Rising Atmospheric Carbon Dioxide , 2004 .

[68]  W. Parton,et al.  Grassland biogeochemistry: Links to atmospheric processes , 1990 .