Representing northern peatland microtopography and hydrology within the Community Land Model

Abstract. Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth for a vegetated wetland, independent of prescribed regional water tables. We introduce here a new configuration of the Community Land Model (CLM) which includes a fully prognostic water table calculation for a vegetated peatland. Our structural and process changes to CLM focus on modifications needed to represent the hydrologic cycle of bogs environment with perched water tables, as well as distinct hydrologic dynamics and vegetation communities of the raised hummock and sunken hollow microtopography characteristic of peatland bogs. The modified model was parameterized and independently evaluated against observations from an ombrotrophic raised-dome bog in northern Minnesota (S1-Bog), the site for the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE). Simulated water table levels compared well with site-level observations. The new model predicts hydrologic changes in response to planned warming at the SPRUCE site. At present, standing water is commonly observed in bog hollows after large rainfall events during the growing season, but simulations suggest a sharp decrease in water table levels due to increased evapotranspiration under the most extreme warming level, nearly eliminating the occurrence of standing water in the growing season. Simulated soil energy balance was strongly influenced by reduced winter snowpack under warming simulations, with the warming influence on soil temperature partly offset by the loss of insulating snowpack in early and late winter. The new model provides improved predictive capacity for seasonal hydrological dynamics in northern peatlands, and provides a useful foundation for investigation of northern peatland carbon exchange.

[1]  T. A. Black,et al.  Hydrological effects on carbon cycles of Canada’s forests and wetlands , 2006 .

[2]  Stephen D. Sebestyen,et al.  Uncertainty in Peat Volume and Soil Carbon Estimated Using Ground‐Penetrating Radar and Probing , 2012 .

[3]  S. Kanae,et al.  Global Hydrological Cycles and World Water Resources , 2006, Science.

[4]  J. Canadell,et al.  Peatlands and the carbon cycle: from local processes to global implications - a synthesis , 2008 .

[5]  Changsheng Li,et al.  An integrated model of soil, hydrology, and vegetation for carbon dynamics in wetland ecosystems , 2002 .

[6]  Dennis P. Lettenmaier,et al.  Modeling the large-scale effects of surface moisture heterogeneity on wetland carbon fluxes in the West Siberian Lowland , 2013 .

[7]  T. Moore,et al.  A comparison of dynamic and static chambers for methane emission measurements from subarctic fens , 1991 .

[8]  F. Warren,et al.  Peat CO2 production in a natural and cutover peatland: Implications for restoration , 2001 .

[9]  Patrick M. Crill,et al.  Modeling seasonal to annual carbon balance of Mer Bleue Bog, Ontario, Canada , 2002 .

[10]  E. Tuittila,et al.  The resilience and functional role of moss in boreal and arctic ecosystems. , 2012, The New phytologist.

[11]  B. Turner.  The Earth as Transformed by Human Action , 1988 .

[12]  Steve Frolking,et al.  A new model of Holocene peatland net primary production, decomposition, water balance, and peat accumulation , 2010 .

[13]  D. I. Sebacher,et al.  Carbon Emissions from Peatlands , 2011 .

[14]  J. Silvola.  Combined effects of varying water content and CO2 concentration on photosynthesis in Spagnum fuscum , 1990 .

[15]  Kenneth Brooks,et al.  Peatland Biogeochemistry and Watershed Hydrology at the Marcell Experimental Forest , 2011 .

[16]  D. F. Grigal,et al.  A simulation model of mire patterning , 1988 .

[17]  T. Lindholm,et al.  Moisture conditions in hummocks and hollows in virgin and drained sites on the raised bog Laaviosuo, southern Finland , 1984 .

[18]  W. Ju,et al.  Effects of topography on simulated net primary productivity at landscape scale. , 2007, Journal of environmental management.

[19]  A. Desai,et al.  Modelling contrasting responses of wetland productivity to changes in water table depth , 2012 .

[20]  Randall K. Kolka,et al.  Analysis of airborne LiDAR surveys to quantify the characteristic morphologies of northern forested wetlands , 2010 .

[21]  S. Verma,et al.  Scaling Up Evapotranspiration Estimates from Process Studies to Watersheds , 2011 .

[22]  E. Gorham.  Northern Peatlands: Role in the Carbon Cycle and Probable Responses to Climatic Warming. , 1991, Ecological applications : a publication of the Ecological Society of America.

[23]  S. Wofsy,et al.  High sensitivity of peat decomposition to climate change through water-table feedback , 2008 .

[24]  S. Idso.  A set of equations for full spectrum and 8- to 14-μm and 10.5- to 12.5-μm thermal radiation from cloudless skies , 1981 .

[25]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .

[26]  M. Nilsson,et al.  Simulation of six years of carbon fluxes for a sedge‐dominated oligotrophic minerogenic peatland in Northern Sweden using the McGill Wetland Model (MWM) , 2013 .

[27]  E. S. Verry,et al.  Establishing the Marcell Experimental Forest: Threads in time. Chapter 1. , 2011 .

[28]  P. Thornton,et al.  A microbial functional group‐based module for simulating methane production and consumption: Application to an incubated permafrost soil , 2015 .

[29]  David M. Lawrence,et al.  Improved simulation of the terrestrial hydrological cycle in permafrost regions by the Community Land Model , 2012 .

[30]  Scott L. Painter,et al.  Modeling challenges for predicting hydrologic response to degrading permafrost , 2013, Hydrogeology Journal.

[31]  Lawrence B. Flanagan,et al.  Effect of changes in water content on photosynthesis, transpiration and discrimination against 13CO2 and C18O16O in Pleurozium and Sphagnum , 1996, Oecologia.

[32]  Miguel A. Medina,et al.  A wetland hydrology and water quality model incorporating surface water/groundwater interactions , 2007 .

[33]  Gavin Gong,et al.  Land surface insulation response to snow depth variability , 2010 .

[34]  Kenneth W Childs,et al.  A method for experimental heating of intact soil profiles for application to climate change experiments , 2011 .

[35]  Zong-Liang Yang,et al.  A simple TOPMODEL-based runoff parameterization (SIMTOP) for use in global climate models , 2005 .

[36]  R. Grant,et al.  Modeling the effects of hydrology on gross primary productivity and net ecosystem productivity at Mer Bleue bog , 2011 .

[37]  Weimin Ju,et al.  Spatially explicit simulation of peatland hydrology and carbon dioxide exchange: Influence of mesoscale topography , 2008 .

[38]  A. W. Damman.  Distribution and movement of elements in ombrotrophic peat , 1978 .

[39]  K. Brooks,et al.  Streamflow response from an ombrotrophic mire , 1988 .

[40]  W. J. Riley,et al.  Barriers to predicting changes in global terrestrial methane fluxes: analyses using CLM4Me, a methane biogeochemistry model integrated in CESM , 2011 .

[41]  Xin Yao,et al.  Stochastic ranking for constrained evolutionary optimization , 2000, IEEE Trans. Evol. Comput..

[42]  David M. Lawrence,et al.  Incorporating organic soil into a global climate model , 2008 .

[43]  P. Martikainen,et al.  CO2 fluxes from peat in boreal mires under varying temperature and moisture conditions. , 1996 .

[44]  Maarten B. Eppinga,et al.  Nutrients and Hydrology Indicate the Driving Mechanisms of Peatland Surface Patterning , 2009, The American Naturalist.

[45]  S. Macdonald,et al.  Factors influencing size inequality in peatland black spruce and tamarack: evidence from post‐drainage release growth , 1999 .

[46]  D. F. Grigal,et al.  Atmospheric Inputs of Mercury and Organic Carbon into a Forested Upland/Bog Watershed , 1999 .

[47]  L. R. Belyea,et al.  The role of hydrological transience in peatland pattern formation , 2013 .

[48]  Scott C. Doney,et al.  Marine Ecosystem Dynamics and Biogeochemical Cycling in the Community Earth System Model [CESM1(BGC)]: Comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 Scenarios , 2013 .

[49]  M. Nungesser.  Modelling microtopography in boreal peatlands: hummocks and hollows , 2003 .

[50]  R. Grant,et al.  Modelling effects of seasonal variation in water table depth on net ecosystem CO 2 exchange of a tropical peatland , 2013 .

[51]  Dennis P. Lettenmaier,et al.  Hydrology: Water from on high , 2006, Nature.

[52]  Charles Tarnocai,et al.  The Impact of Climate Change on Canadian Peatlands , 2009 .

[53]  S. Frolking,et al.  McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments , 2008 .

[54]  Scott D. Bridgham,et al.  The carbon balance of North American wetlands , 2006, Wetlands.

[55]  E. S. Verry,et al.  Stream flow and ground water recharge from small forested watersheds in north central Minnesota , 2001 .

[56]  E. S. Verry,et al.  of the S2 Bog at the MEF: 12,000 Years in Northern Minnesota , 2011 .

[57]  Hendrik Poorter,et al.  Interactive effects of water table and precipitation on net CO2 assimilation of three co‐occurring Sphagnum mosses differing in distribution above the water table , 2009 .

[58]  D. Nichols,et al.  Temperature of upland and peatland soils in a north central Minnesota forest , 1998 .

[59]  William J. Sacks,et al.  Effects of global irrigation on the near-surface climate , 2009 .

[60]  Steve Frolking,et al.  Interannual variability in the peatland‐atmosphere carbon dioxide exchange at an ombrotrophic bog , 2003 .

[61]  M. Torn,et al.  The effect of vertically resolved soil biogeochemistry and alternate soil C and N models on C dynamics of CLM4 , 2013 .

[62]  Hans Joosten,et al.  Self‐organization in raised bog patterning: the origin of microtope zonation and mesotope diversity , 2005 .

[63]  T. Moore.  Growth and net production of Sphagnum at five fen sites, subarctic eastern Canada , 1989 .

[64]  S. Gower,et al.  Improved simulation of poorly drained forests using Biome-BGC. , 2007, Tree physiology.

[65]  Yinghai Ke,et al.  Evaluating runoff simulations from the Community Land Model 4.0 using observations from flux towers and a mountainous watershed , 2011 .

[66]  K. E. Moore,et al.  A season of heat, water vapor, total hydrocarbon, and ozone fluxes at a subarctic fen , 1994 .

[67]  A. W. Damman,et al.  Species-controlled Sphagnum decay on a South Swedish raised bog , 1991 .

[68]  E. S. Verry.  Microtropography and water table fluctuation in a sphagnum mire , 1984 .

[69]  F. Chapin,et al.  Soil Temperature and Nutrient Cycling in the Tussock Growth Form of Eriophorum Vaginatum , 1979 .

[70]  I. Prentice,et al.  Implementation and evaluation of a new methane model within a dynamic global vegetation model: LPJ-WHyMe v1.3.1 , 2010 .

[71]  Peter E. Thornton,et al.  Improvements to the Community Land Model and their impact on the hydrological cycle , 2008 .

[72]  M. Kanamitsu,et al.  NCEP–DOE AMIP-II Reanalysis (R-2) , 2002 .

[73]  Weimin Ju,et al.  Distributed hydrological model for mapping evapotranspiration using remote sensing inputs , 2005 .

[74]  W. Oechel,et al.  The Role of Bryophytes in Nutrient Cycling in the Taiga , 1986 .

[75]  Tim R. Moore,et al.  Modelling and analysis of peatlands as dynamical systems , 2000 .

[76]  R. Kolka,et al.  Long-Term Monitoring Sites and Trends at the Marcell Experimental Forest , 2012 .

[77]  P. Bartlett,et al.  Seasonal trends in energy, water, and carbon dioxide fluxes at a northern boreal wetland , 1997 .

[78]  Satish Karra,et al.  Constitutive Model for Unfrozen Water Content in Subfreezing Unsaturated Soils , 2014 .

[79]  T. Malterer,et al.  Physical Properties of Organic Soils , 2011 .

[80]  J. Titus,et al.  Vertical zonation of Sphagnum mosses along hummock-hollow gradients , 1983 .

[81]  M. Wilmking,et al.  Evapotranspiration dynamics in a boreal peatland and its impact on the water and energy balance , 2010 .

[82]  Zong-Liang Yang,et al.  Technical description of version 4.5 of the Community Land Model (CLM) , 2013 .

[83]  John S. Woollen,et al.  NCEP-DOE AMIP-II reanalysis (R-2). Bulletin of the American Meteorological Society . , 2002 .