Geophysical Applications of Vegetation Modeling

This thesis describes the development and selected applications of a global vegetation model, BIOME4. The model is applied to problems in high-latitude vegetation distribution and climate, trace gas production, and isotope biogeochemistry. It demonstrates how a modeling approach, based on principles of plant physiology and ecology, can be applied to interdisciplinary problems that cannot be adequately addressed by direct observations or experiments. The work is relevant to understanding the potential effects of climate change on the terrestrial biosphere and the feedbacks between the biosphere and climate. BIOME4 simulates the distribution of 15 high-latitude biomes, including five tundra vegetation types, for the present day using observed climate, and the LGM, mid-Holocene, and a “greenhouse” scenario for 2100 using the output of GCMs. In the LGM simulations, the high-latitudes show a marked increase in the area of graminoid and forb tundra, which is also the predominant feature in the paleodata. This vegetation has no widespread modern analog; it was favored by the cold, dry climate, and supported large mammoth populations. Mid-Holocene simulations indicate a modest, asymmetrical northward advance of the Arctic treeline compared to present, with greatest extension in central Siberia (up to 300 km), and little to no change in the Western Hemisphere. This result is in good agreement with pollen and megafossil data from the same period. Differential warming of the continents in response to increased high-latitude solar radiation is hypothesized to account for the asymmetry. Vegetation changes in the 2100 projection, which assumes a continued exponential increase in atmospheric GHG concentrations, are more radical than those simulated for the mid-Holocene. The year-round forcing due to GHGs increases both summertime and annual temperatures in the high latitudes by up to double the mid-Holocene anomaly. However the potential treeline advances and biome shifts in our simulation are unlikely to be realized within 100 years, because of the time required for migration and establishment of new vegetation types. Potential natural wetland area for the present day was simulated by BIOME4 as 11.0x106km2. This value is higher than other estimates but includes small (<50km2) and seasonal wetlands which have not been included in previous surveys. The wetland CH4 source was simulated as 140Tgyr-1. At the LGM, simulated wetland area was increased by 15% but CH4 emissions were 24% less than the present-day. The simulated reduction in the CH4 source is due to substrate limitation induced by low atmospheric CO2 concentrations at the LGM. The 100% increase in atmospheric CH4 concentrations measured in ice cores between the LGM and the preindustrial Holocene may not be due to changes in CH4 source strength alone, as other trace gases influence the atmospheric CH4 sink. The stable carbon isotope composition of the terrestrial biosphere was simulated by BIOME4 and compared to measurements at the leaf, ecosystem and troposphere scales. Model simulations are correlated within one standard deviation to measured means at the PFT and biome scales, and at six Northern Hemisphere CO2 monitoring stations. Global carbon isotope discrimination in the terrestrial biosphere averaged 18.6‰ for potential natural vegetation and 18.1‰ when an agricultural landuse mask was applied. These simulated values are slightly higher than previous estimates, but consistent with measurements. This information is important for the interpretation of contemporary atmospheric observations in terms of carbon sources and sinks on land and in the ocean.

[1]  Sandy P. Harrison,et al.  Dust sources and deposition during the last glacial maximum and current climate: A comparison of model results with paleodata from ice cores and marine sediments , 1999 .

[2]  D. Walker,et al.  Hierarchical subdivision of Arctic tundra based on vegetation response to climate, parent material and topography , 2000, Global change biology.

[3]  C. Deser.  On the teleconnectivity of the “Arctic Oscillation” , 2000 .

[4]  C. Potter.  An ecosystem simulation model for methane production and emission from wetlands , 1997 .

[5]  E. T. Linacre,et al.  Estimating the net-radiation flux , 1968 .

[6]  Gordon B. Bonan,et al.  Land-atmosphere CO2 exchange simulated by a land surface process model coupled to an atmospheric general circulation model , 1995 .

[7]  J. Malcolm.  Global Warming and Terrestrial Biodiversity Decline , 2000 .

[8]  Michael T. Coe,et al.  A linked global model of terrestrial hydrologic processes: Simulation of modern rivers, lakes, and wetlands , 1998 .

[9]  M. Edwards,et al.  A Late Wisconsin and Holocene Vegetation History from the Central Brooks Range: Implications for Alaskan Palaeoecology , 1983, Quaternary Research.

[10]  James F. Reynolds,et al.  Steppe-Tundra Transition: A Herbivore-Driven Biome Shift at the End of the Pleistocene , 1995, The American Naturalist.

[11]  A. Sharon.  Simulated effects of low atmospheric CO2 on structure and composition of North American vegetation at the Last Glacial Maximum , 1999 .

[12]  Graham D. Farquhar,et al.  Modelling of Photosynthetic Response to Environmental Conditions , 1982 .

[13]  Corinna Rebmann,et al.  Productivity of forests in the Eurosiberian boreal region and their potential to act as a carbon sink –‐ a synthesis , 1999 .

[14]  Donald J. Cavalieri,et al.  Arctic sea ice extents, areas, and trends, 1978-1996 , 1999 .

[15]  A. M. Solomon,et al.  Integrating forest-stand simulations with paleoecological records to examine long-term forest dynamics , 1983 .

[16]  T. Webb,.  Past Global Changes and Their Significance for the Future , 2001 .

[17]  D. Pollard,et al.  Large-Scale Vegetation Feedbacks on a Doubled CO2 Climate , 2000 .

[18]  R. Fairbanks.  A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation , 1989, Nature.

[19]  Enrong Lu,et al.  Ranking the overall performance of eight sunshine-based global solar radiation models with a nonparametric statistical procedure , 1999 .

[20]  Kevin E. Trenberth,et al.  A global monthly sea surface temperature climatology , 1992 .

[21]  I. Prentice,et al.  The climate and biomes of Europe at 6000 yr BP: Comparison of model simulations and pollen-based reconstructions , 1998 .

[22]  H. Treut,et al.  Sensitivity of the LMD General Circulation Model to Greenhouse Forcing Associated with Two Different Cloud Water Parameterizations , 1994 .

[23]  J. Pinto,et al.  The stability of tropospheric OH during ice ages, inter‐glacial epochs and modern times , 1991 .

[24]  Sandy P. Harrison,et al.  How well can we simulate past climates? Evaluating the models using global palaeoenvironmental datasets , 2000 .

[25]  Michael F. Hutchinson,et al.  A new method for estimating the spatial distribution of mean seasonal and annual rainfall applied to the Hunter Valley, New South Wales , 1983 .

[26]  S. Harrison.  Palaeovironmental data sets and model evaluation in PMIP , 2000 .

[27]  I. Prentice,et al.  A general model for the light-use efficiency of primary production , 1996 .

[28]  P. Richards,et al.  Vegetation of the Earth in Relation to Climate and the Eco-Physiological Conditions. , 1975 .

[29]  J. Glover,et al.  The empirical relation between solar radiation and hours of sunshine , 1958 .

[30]  E. Nisbet.  Sources of atmospheric CH4 in early postglacial time , 1992 .

[31]  J. Kutzbach,et al.  Response of the African Monsoon to Orbital Forcing and Ocean Feedbacks in the Middle Holocene , 1997 .

[32]  J. Randerson,et al.  Carbon 13 exchanges between the atmosphere and biosphere , 1997 .

[33]  J. Kutzbach,et al.  Fully coupled climate/dynamical vegetation model simulations over Northern Africa during the mid-Holocene , 2000 .

[34]  Ge Yu,et al.  Late Quaternary Lake-Level Record from Northern Eurasia , 1996, Quaternary Research.

[35]  John F. B. Mitchell,et al.  Climate change scenarios for global impacts studies , 1999 .

[36]  I. Fung,et al.  The atmospheric CH4 increase since the Last Glacial Maximum. II - Interactions with oxidants , 1993 .

[37]  C. D. Keeling,et al.  Recent trends in the 13C/12C ratio of atmospheric carbon dioxide , 1979, Nature.

[38]  L. Cwynar,et al.  Evidence from north-west Canada for an early Holocene Milankovitch thermal maximum , 1983, Nature.

[39]  P. Crutzen,et al.  A model study of atmospheric temperatures and the concentrations of ozone, hydroxyl, and some other photochemically active gases during the glacial, the pre-industrial holocene and the present , 1993 .

[40]  Jed O. Kaplan,et al.  Trace gas exchange in a high‐Arctic valley: 1. Variationsin CO2 and CH4 Flux between tundra vegetation types , 2000 .

[41]  B. A. Yurtsev.  The Pleistocene ``Tundra-Steppe'' and the productivity paradox: the landscape approach , 2001 .

[42]  Jonathan A. Foley,et al.  An equilibrium model of the terrestrial carbon budget , 1995 .

[43]  Eric S. Kasischke,et al.  Monitoring South Florida Wetlands Using ERS-1 SAR Imagery , 1997 .

[44]  M. Khalil,et al.  Tropospheric OH: model calculations of spatial, temporal, and secular variations , 1991 .

[45]  A. Ridgwell,et al.  Consumption of atmospheric methane by soils: A process‐based model , 1999 .

[46]  F. Chapin,et al.  Production: Biomass Relationships and Element Cycling in Contrasting Arctic Vegetation Types , 1991 .

[47]  William M. Lewis,et al.  Methane emissions from the Orinoco River floodplain, Venezuela , 2000 .

[48]  P. Boon,et al.  Methane oxidation in sediments of a floodplain wetland in south‐eastern Australia , 1997 .

[49]  CARBON CYCLING AND METHANE EXCHANGE IN EURASIAN TUNDRA ECOSYSTEMS , 1999 .

[50]  W. Cramer,et al.  The IIASA database for mean monthly values of temperature , 1991 .

[51]  W. Cramer,et al.  A global biome model based on plant physiology and dominance, soil properties and climate , 1992 .

[52]  R. D. Guthrie.  Origin and causes of the mammoth steppe: a story of cloud cover, woolly mammal tooth pits, buckles, and inside-out Beringia , 2001 .

[53]  Charles D. Keeling,et al.  The concentration and isotopic abundances of atmospheric carbon dioxide in rural areas , 1958 .

[54]  Ronald P. Neilson,et al.  Simulated changes in vegetation distribution under global warming , 1998 .

[55]  C. Hewitt,et al.  A fully coupled GCM simulation of the climate of the mid‐Holocene , 1998 .

[56]  Martin T. Sykes,et al.  Physiological Significance of Low Atmospheric CO2 for Plant–Climate Interactions , 1999, Quaternary Research.

[57]  R. Aravena,et al.  Holocene Treeline History and Climate Change Across Northern Eurasia , 2000, Quaternary Research.

[58]  John M. Norman,et al.  Carbon distribution and aboveground net primary production in aspen, jack pine, and black spruce stands in Saskatchewan and Manitoba, Canada , 1997 .

[59]  Sander Houweling,et al.  The modeling of tropospheric methane: How well can point measurements be reproduced by a global model? , 2000 .

[60]  A. Angstroem.  Solar and terrestrial radiation , 1924 .

[61]  Shalina,et al.  Satellite Evidence for an Arctic Sea Ice Cover in Transformation. , 1999, Science.

[62]  S. Elias.  Mutual climatic range reconstructions of seasonal temperatures based on Late-Pleistocene fossil beetle assemblages in Eastern Beringia , 2001 .

[63]  Jerome Chappellaz,et al.  Changes in the atmospheric CH4 gradient between Greenland and Antarctica during the Holocene , 1997 .

[64]  Terry V. Callaghan,et al.  On the potential CO2 release from tundra soils in a changing climate , 1999 .

[65]  B. Henderson-Sellers.  Calculating the Surface Energy Balance for Lake and Reservoir Modeling: A Review (Paper 6R0209) , 1986 .

[66]  I. Fung,et al.  The atmospheric CH4 increase since the Last Glacial Maximum. I - Source estimates , 1993 .

[67]  B. A. Yurtsev.  9 – RELICS OF THE XEROPHYTE VEGETATION OF BERINGIA IN NORTHEASTERN ASIA , 1982 .

[68]  D. Pollard,et al.  CO2, climate, and vegetation feedbacks at the Last Glacial Maximum , 1999 .

[69]  J. Ehleringer,et al.  Carbon isotope ratios in belowground carbon cycle processes , 2000 .

[70]  S. Sitch.  The role of vegetation dynamics in the control of atmospheric CO2 content , 2000 .

[71]  Prof. Dr. Walter Tranquillini.  Physiological Ecology of the Alpine Timberline , 1979, Ecological Studies.

[72]  P. Tans,et al.  Global Carbon Sinks and Their Variability Inferred from Atmospheric O2 and δ13C , 2000 .

[73]  Edward J. Dlugokencky,et al.  The growth rate and distribution of atmospheric methane , 1994 .

[74]  M. Hutchinson,et al.  A comparison of two statistical methods for spatial interpolation of Canadian monthly mean climate data , 2000 .

[75]  J. Mitchell,et al.  Climate simulations for 9000 years before present: Seasonal variations and effect of the Laurentide ice sheet , 1988 .

[76]  U. Emanuelsson.  Ecological effects of grazing and trampling on mountain vegetation in northern Sweden. , 1984 .

[77]  S. P. S. Kushwaha,et al.  Evaluation of various digital image processing techniques for detection of coastal wetlands using ERS-1 SAR data , 2000 .

[78]  Potential and actual trace gas fluxes in Arctic terrestrial ecosystems , 1999 .

[79]  B. Sorrell,et al.  Methane Fluxes from an Australian Floodplain Wetland: The Importance of Emergent Macrophytes , 1995, Journal of the North American Benthological Society.

[80]  Graham D. Farquhar,et al.  Temperature dependence of whole-leaf photosynthesis in Eucalyptus pauciflora Sieb , 1984 .

[81]  Roger G. Barry,et al.  Recent decreases in Arctic summer ice cover and linkages to atmospheric circulation anomalies , 1996 .

[82]  F. Stuart Chapin,et al.  Plant functional types as predictors of transient responses of arctic vegetation to global change , 1996 .

[83]  W. Larcher.  Physiological Plant Ecology: Ecophysiology and Stress Physiology of Functional Groups , 1995 .

[84]  E. Nisbet.  The end of the ice age , 1990 .

[85]  S. Cowling.  Plant-climate interactions over historical and geological time , 2000 .

[86]  P. Boon,et al.  Methane Flux from Beds of Baumea arthrophylla (Nees) Boeckeler and Triglochin procerum R. Br. at Bool Lagoon, South Australia , 1994 .

[87]  G. Ramstein,et al.  Tropical paleoclimates at the Last Glacial Maximum: comparison of Paleoclimate Modeling Intercomparison Project (PMIP) simulations and paleodata , 1999 .

[88]  P. Valdes,et al.  Simulations of the Last Glacial Maximum climates using a general circulation model: prescribed versus computed sea surface temperatures , 1998 .

[89]  R. D. Guthrie,et al.  Paleoecological Significance of Mummified Remains of Pleistocene Horses from the North Slope of the Brooks Range, Alaska , 1990 .

[90]  I. Colin Prentice,et al.  A coupled carbon and water flux model to predict vegetation structure , 1996 .

[91]  G. Miller,et al.  The Last great ice sheets , 1981 .

[92]  G. Ramstein,et al.  Cloud processes associated with past and future climate changes , 1998 .

[93]  J. Lerner,et al.  Three‐dimensional model synthesis of the global methane cycle , 1991 .

[94]  A. Mix,et al.  Reassessment of ice-age cooling of the tropical ocean and atmosphere , 1999, Nature.

[95]  André Berger,et al.  Long-term variations of daily insolation and Quaternary climatic changes , 1978 .

[96]  K. Lambeck,et al.  Refining the eustatic sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites , 1998 .

[97]  Paul J. Crutzen,et al.  An inverse modeling approach to investigate the global atmospheric methane cycle , 1997 .

[98]  W. Oechel,et al.  Acclimation of ecosystem CO2 exchange in the Alaskan Arctic in response to decadal climate warming , 2000, Nature.

[99]  Chris D. Clark,et al.  Geomorphological reconstruction of the Labrador Sector of the Laurentide Ice Sheet , 2000 .

[100]  Ge Yu,et al.  Pollen-based reconstruction of vegetation patterns of China in mid-Holocene , 1998 .

[101]  J. C. Ritchie.  Late-Quaternary Climatic and Vegetational Change in the Lower Mackenzie Basin, Northwest Canada , 1985 .

[102]  J. Kutzbach,et al.  Feedbacks between climate and boreal forests during the Holocene epoch , 1994, Nature.

[103]  John E. Walsh,et al.  Recent Variations of Sea Ice and Air Temperature in High Latitudes , 1993 .

[104]  Paul J. Crutzen,et al.  Global distribution of natural freshwater wetlands and rice paddies, their net primary productivity, seasonality and possible methane emissions , 1989 .

[105]  Charles D. Keeling,et al.  The concentration and isotopic abundances of carbon dioxide in rural and marine air , 1961 .

[106]  M. G. Ryan,et al.  Comparing nocturnal eddy covariance measurements to estimates of ecosystem respiration made by scaling chamber measurements at six coniferous boreal sites , 1997 .

[107]  B. C. Hansen,et al.  Vegetation and environment in Eastern North America during the Last Glacial Maximum , 2000 .

[108]  B. Felzer.  Climate impacts of an ice sheet in East Siberia during the last glacial maximum , 2001 .

[109]  Mingkui Cao,et al.  Global carbon exchange and methane emissions from natural wetlands : Application of a process-based model , 1996 .

[110]  Thomas Kaminski,et al.  Sensitivity of the seasonal cycle of CO2 at remote monitoring stations with respect to seasonal surface exchange fluxes determined with the adjoint of an atmospheric transport model , 1996 .

[111]  P. Ciais,et al.  A Large Northern Hemisphere Terrestrial CO2 Sink Indicated by the 13C/12C Ratio of Atmospheric CO2 , 1995, Science.

[112]  G. Ramstein,et al.  Impact of parameterizations on simulated winter mid‐Holocene and Last Glacial Maximum climatic changes in the northern hemisphere , 1998 .

[113]  Pieter P. Tans,et al.  Evidence for interannual variability of the carbon cycle from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory Global Air Sampling Network , 1994 .

[114]  Hans Olsson.  Studies on south Swedish sand vegetation , 1974 .

[115]  Inez Y. Fung,et al.  Methane emission from natural wetlands: Global distribution, area, and environmental characteristics of sources , 1987 .

[116]  P. Braconnot,et al.  Ocean Feedback in Response to 6 kyr BP Insolation , 2000 .

[117]  M. Maslin,et al.  Variations in Atlantic surface ocean paleoceanography, 50°-80°N: A time-slice record of the last 30,000 years , 1995 .

[118]  J. Chappellaz,et al.  Variations in atmospheric methane concentration during the Holocene epoch , 1995, Nature.

[119]  C. J. Stigter.  Solar radiation as statistically related to sunshine duration: a comment using low-latitude data. , 1980 .

[120]  G. Thelin.  Nutrient imbalance in Norway spruce , 2000 .

[121]  J. Jouzel,et al.  Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica , 1999, Nature.

[122]  Permalink,et al.  Arctic and boreal ecosystems of western North America as components of the climate system , 2000, Global change biology.

[123]  A. Sher,et al.  Holocene dwarf mammoths from Wrangel Island in the Siberian Arctic , 1993, Nature.

[124]  M. Coe.  The Hydrologic Cycle of Major Continental Drainage and Ocean Basins: A Simulation of the Modern and Mid-Holocene Conditions and a Comparison with Observations , 1995 .

[125]  J. Schwander,et al.  Synchronous changes in atmospheric CH4 and Greenland climate between 40 and 8 kyr BP , 1993, Nature.

[126]  J. Berry,et al.  Environmental Regulation of Photosynthesis , 1982 .

[127]  B. Carlsson.  Controls on the growth and population dynamics of Carex bigelowii. , 1990 .

[128]  M. F. Hutchinson,et al.  Interpolating Mean Rainfall Using Thin Plate Smoothing Splines , 1995, Int. J. Geogr. Inf. Sci..

[129]  F. Chapin,et al.  Calcium-rich tundra, wildlife, and the "Mammoth Steppe" , 2001 .

[130]  Michael L. Roderick,et al.  Estimating the diffuse component from daily and monthly measurements of global radiation , 1999 .

[131]  P. Cox,et al.  Response of methane emission from arctic tundra to climatic change: results from a model simulation , 1995 .

[132]  N. Noblet,et al.  Quantifying the role of biosphere-atmosphere feedbacks in climate change: coupled model simulations for 6000 years BP and comparison with palaeodata for northern Eurasia and northern Africa , 1997 .

[133]  B. Stauffer,et al.  Changes in the atmospheric CH4 gradient between Greenland and Antarctica during the Last Glacial and the transition to the Holocene , 2000 .

[134]  A. Mix,et al.  Late Quaternary Paleoceanography of the Tropical Atlantic, 1: Spatial Variability of Annual Mean Sea-Surface Temperatures, 0-20,000 Years B.P. , 1986 .

[135]  G. Brasseur,et al.  The chemical composition of ancient atmospheres: A model study constrained by ice core data , 1995 .

[136]  I. C. Prentice,et al.  BIOME3: An equilibrium terrestrial biosphere model based on ecophysiological constraints, resource availability, and competition among plant functional types , 1996 .

[137]  A. Lozhkin,et al.  Late Quaternary paleoenvironments and modern pollen data from Wrangel Island (Northern Chukotka) , 2001 .

[138]  J. Severinghaus,et al.  On the origin and timing of rapid changes in atmospheric methane during the Last Glacial Period , 2000 .

[139]  John M. Melack,et al.  Passive microwave observations of inundation area and the area/stage relation in the Amazon River floodplain , 1998 .

[140]  J. Ehleringer,et al.  Carbon isotope discrimination of terrestrial ecosystems , 1998 .

[141]  N. Noblet,et al.  Synergistic feedbacks from ocean and vegetation on the African Monsoon response to Mid‐Holocene insolation , 1999 .

[142]  S. Vavrus.  The Response of the Coupled Arctic Sea Ice–Atmosphere System to Orbital Forcing and Ice Motion at 6 kyr and 115 kyr BP , 1999 .

[143]  M. Fontugne,et al.  Atmospheric methane ratio and environmental change in the Sahara an Sahel during the last 130 kyrs , 1991 .

[144]  U. Nordén.  Soil acidification and element fluxes as related to tree species in deciduous forests of south Sweden , 1992 .

[145]  F. Woodward,et al.  Increases in terrestrial carbon storage from the Last Glacial Maximum to the present , 1990, Nature.

[146]  A. Haxeltine.  Modelling the vegetation of the Earth , 1996 .

[147]  M. Edwards,et al.  A TUNDRA-STEPPE TRANSITION ON KATHUL MOUNTAIN, ALASKA, U.S.A. , 1989 .

[148]  P. Tarasov,et al.  Last glacial maximum biomes reconstructed from pollen and plant macrofossil data from northern Eurasia , 2000 .

[149]  S. Harrison.  Tropical climates at the Last Glacial Maximum , 2001 .

[150]  Khelifa,et al.  Impact of lower atmospheric carbon dioxide on tropical mountain ecosystems , 1997, Science.

[151]  J. Kutzbach,et al.  Vegetation and soil feedbacks on the response of the African monsoon to orbital forcing in the early to middle Holocene , 1996, Nature.