The BOREAS Information System

BIOME-BGC Simulations of Stand Hydrology, Productivity, Surface-Atmosphere Carbon and Water Exchange at Selected BOREAS Tower Flux Sites for 1994


Summary

BIOME-BGC is a general ecosystem process model designed to simulate biogeochemical and hydrologic processes across multiple scales (Running and Hunt 1993). In this investigation we used BIOME-BGC to estimate daily water and carbon budgets for the boreas tower flux sites for 1994. Carbon variables estimated by the model include gross primary production (i.e. net photosynthesis), maintenance and heterotrophic respiration, net primary production and net ecosystem C exchange. Hydrologic variables estimated by the model include snowcover, evaporation, transpiration, evapotranspiration, soil moisture and outflow.


Table of Contents

  1. Model Overview
  2. Investigator(s)
  3. Model Theory
  4. Equipment
  5. Data Acquisition Methods
  6. Observations
  7. Data Description
  8. Data Organization
  9. Data Manipulations
  10. Errors
  11. Notes
  12. Application of the Model
  13. Future Modifications and Plans
  14. Software
  15. Data Access
  16. Output Products and Availability
  17. References
  18. Glossary of Terms
  19. List of Acronyms
  20. Document Information


1. Model Overview

1.1 Model Identification
BIOME-BGC (BioGeoChemical cycles)

1.2 Model Introduction
BIOME-BGC simulates biogeochemical and hydrologic processes across multiple biomes based on the logic that differences in process rates between biomes are primarily a function of climate and general life-form characteristics. The carbon balance portion of BIOME-BGC utilizes daily meteorological data in conjunction with general stand and soil information to predict net photosynthesis, growth, maintenance and heterotrophic respiration at a daily time-step. BIOME-BGC is general in the sense that the surface is represented by singular, homogeneous canopy and soil layers. Detailed descriptions of BIOME-BGC logic are given by Running and Coughlan (1988) and Running and Hunt (1993). A description of the components of the model relating to the prediction of hydrologic characteristics within different boreal forest stands is given by Kimball and Running (submitted). A summary of the important components of BIOME-BGC relating to the prediction of daily carbon allocation and exchange is given below.

1.3 Objective/Purpose
In this investigation we used BIOME-BGC to estimate daily and annual hydrologic and carbon budgets for different boreal forest stands associated with the boreas tower flux sites and compared net carbon flux estimates with results derived from tower flux and biomass measurement data. These results were used to assess the important climate and stand characteristics that control stand hydrologic characteristics, estimated productivity respiration and surface-atmosphere carbon exchange. These results are intended to provide a framework for evaluating the sensitivity of the boreal forest regional carbon balance to global warming.


1.4 Summary of Parameters

Model daily input requirements:
Maximum and minimum daily air temperature (C), precipitation (cm), total daily solar radiation (kJ) and daylength (s).
There is also a site initialization file that describes stand morphology and soil characteristics. Parameters included in this file are discussed in section 1.5. Site initialization files that were used to generate model results for the sites in this investigation are included in this data directory.

Model daily carbon outputs:
Net photosynthesis (GPP); maintenance (Rm), growth (Rg), heterotrophic (Rh) and total respiration (Rtot); net ecosystem C exchange (NEE). Rm represents the daily sum of estimated maintenance respiration rates from coarse and fine root, sapwood and foliar carbon pools. foliar respiration is computed as the sum of estimated day and night foliar respiration rates. GPP is computed as the difference between gross photosynthesis and day leaf respiration. NPP is determined as the difference between GPP and Rm. Rg was estimated as 32% of the daily estimated NPP. Rh is estimated as a proportion of prescribed soil and litter carbon pools; this proportion is regulated by estimated soil water potential and soil temperature conditions. Rtot is estimated as the sum of Rm, Rg, and Rh. NEE is estimated as the difference between GPP and Rtot.

Model daily hydrologic outputs:
Evaporation, transpiration, evapotranspiration, soil moisture, snow water equivalent.


1.5 Discussion
BIOME-BGC simulates biogeochemical and hydrologic processes across multiple biomes based on the logic that differences in process rates between biomes are primarily a function of climate and general life-form characteristics. The carbon balance portion of BIOME-BGC utilizes daily meteorological data in conjunction with general stand and soil information to predict net photosynthesis, growth, maintenance and heterotrophic respiration at a daily time-step. BIOME-BGC is general in the sense that the surface is represented by singular, homogeneous canopy and soil layers. Detailed descriptions of BIOME-BGC logic are given by Running and Coughlan (1988) and Running and Hunt (1993). A description of the components of the model relating to the prediction of hydrologic characteristics within different boreal forest stands is given by Kimball and Running (submitted). A summary of the important components of BIOME-BGC relating to the prediction of daily carbon allocation and exchange is given below.
The sole input to the carbon budget in BIOME-BGC is the photosynthetic fixation of CO2 by the vegetation canopy. Outputs are all in the form of respired CO2, coming either from plant tissues due to growth or maintenance respiration, or from the litter and soil carbon pools as the result of heterotrophic respiration.
Gross primary production (GPP) represents the total gain of carbon to the system by net photosynthesis and is defined as the daily sum of gross photosynthesis and daily foliar respiration. The current representation of photosynthesis differs significantly from previously published descriptions of the BGC family of models (Running and Hunt 1993, Hunt and Running 1992, Running and Coughlan 1988). The original FOREST-BGC representation of photosynthesis relies primarily on the parameterization of a mesophyll conductance to CO2, estimating the rate of fixation as a diffusion process, driven by a prescribed internal CO2 concentration. FOREST-BGC also does not implement an explicit treatment of the photosynthetic biochemical pathways. The original version of BIOME-BGC presents a more detailed representation of photosynthesis, relying on explicit models of photosynthetic biochemistry (Leuning 1990, Farquhar et al. 1980). The original BIOME-BGC also includes an iterative calculation of intracellular CO2 concentration (Ci), as well as an explicit calculation of the CO2 compensation point. The current implementation of photosynthetic biochemistry is closely related to the original BIOME-BGC logic in that it is based on the Farquhar biochemical model, but the resulting set of equations is somewhat different due to differences in the logical constraints applied: we solve a quadratic system of equations by elimination of Ci, instead of specifying a value as an initial condition. Other differences include a more detailed dependence of the kinetic parameters on temperature (Woodrow and Berry 1988), and a simplifying assumption that empirically relates the maximum rate of electron transport to the maximum carboxylation velocity (Wullschleger 1993).
Photosynthesis is regulated by the canopy conductance to CO2 (gc), leaf maintenance respiration and daily meteorological conditions including air pressure, air temperature and photosynthetically active photon flux density (PPFD). The maximum canopy conductance to CO2 (gc,max) defines the upper boundary of the photosynthetic rate and is determined by LAI and prescribed leaf-scale boundary layer, cuticular and maximum stomatal conductances; gc is reduced when air temperature, vapor pressure deficit, PPFD, or soil water potential deviate from prescribed optimal conditions (Leuning 1990, Running and Coughlan 1988, Jarvis and Morison 1981). BIOME-BGC represents the canopy as a "big leaf" in that all units of leaf area in the canopy are represented using a single, canopy averaged conductance. This assumption is generally not valid at sub-daily (e.g. hourly) time-steps since the reduction of irradiance at lower vertical layers of the canopy reduces conductances at the bottom of the canopy. The big leaf assumption is strengthened, however, by the integrative effects of a daily time-step, and by the implicit assumption that the allocation of leaf nitrogen between light harvesting and carbon fixing enzymes over depth in the canopy varies in response to the canopy light environment, allowing an optimized use of intercepted radiation (Evans 1989).
Total respiration from the system (Rtot) is estimated on a daily basis as the sum of the maintenance (Rm), heterotrophic (Rh) and growth (Rg) respiration components. Rm represents the total loss of carbon due to day and night leaf respiration (Rdl + Rnl), sapwood (Rsw), coarse root (Rcr) and fine root (Rfr) respiration. Respiration is estimated as a daily proportion of carbon in living tissue that is released as the result of cellular metabolic processes, excluding any growth processes. Rm is calculated from mean daily air temperatures and prescribed leaf, root and sapwood carbon pools using an exponentially increasing function of respiration with temperature following Amthor (1986). The magnitude of the respiration response to temperature is governed by a prescribed rate defined at a reference temperature (i.e. 15 C) and a proportional change in rate for a 10 C change in temperature (Q10). In all cases except leaf maintenance respiration the daily average temperature is used, and a single value is calculated for the mass lost to maintenance respiration for the day. In the case of leaves, however, Rdl and Rnl rates are calculated from estimated day and night air temperatures, respectively, since Rdl is required to determine GPP. Daily growth respiration was not determined explicitly by the model in this investigation; instead Rg was computed as a proportion (32%) of the daily estimated total net primary productivity, NPP (Penning de Vries et al. 1974).
The heterotrophic respiration term in BIOME-BGC represents the loss of carbon from the system resulting from soil microbial respiration. Daily Rh is estimated as a proportion of prescribed soil and litter carbon pools. The proportion of litter carbon being respired on a daily basis is regulated by soil water potential and soil temperature conditions following Orchard and Cook (1983), Andren and Paustian (1987), and Running and Coughlan (1988). The proportion of soil carbon respired on a daily basis was estimated as 1% of the proportion of litter carbon respired based on data for boreal coniferous and deciduous stands (Fox and Van Cleve 1983, Cole and Rapp 1981).
NPP represents the net accumulation of carbon by the stand and is determined as the difference between GPP and the sum of Rm and Rg. The net ecosystem exchange of carbon (NEE) represents the net accumulation or loss of carbon by the entire soil-stand system and is determined as the difference between GPP and Rtot. Positive fluxes in this investigation denote a net uptake of carbon by the system while negative fluxes denote a net loss. Standards for denoting positive and negative fluxes generally vary between different disciplines, however, and net carbon uptake is often denoted as a negative flux in the literature.
BIOME-BGC uses daily maximum and minimum air temperatures, humidity, incident solar radiation and precipitation to determine daily carbon and water fluxes. Average daily incident shortwave radiation (Qi) was simulated using MT-CLIM logic described by Running et al. (1987). Average daily net solar radiation (Qn) was estimated using a prescribed, constant albedo for vegetation. Qn was attenuated through the vegetation canopy using Beer's formulation and a prescribed extinction coefficient modulated by LAI to derive the amount of solar radiation transmitted through the canopy (Qt). The amount of solar radiation absorbed by the canopy (Qa) was estimated as the difference between Qi and Qt. PPFD was estimated based on the assumption that photosynthetically active radiation represents approximately 50% of Qa (Running and Coughlan 1988).
Mean daily air temperature (Ta) was estimated as the average of the measured daily maximum and minimum air temperatures. Minimum daily air temperature was assumed equal to the mean daily dew point and was used to estimate the mean daily vapor pressure deficit (VPD). Daily soil temperatures at a 30 cm soil depth (Tsoil) were estimated using an 11 day running average of Ta (Zheng et al. 1993). Soil water potential (PSI) was estimated from soil water content, soil depth and texture information following Cosby et al. (1984). Ta, VPD, PPFD and PSI were used to estimate gc and GPP following Jarvis and Morison (1981) and Farquhar and von Caemmerer (1982), respectively.
Ta and Tsoil were used to estimate Rm while Tsoil and PSI were used to estimate Rh (Running and Coughlan 1988).

1.6 Related Models
These results represent site specific model runs using BIOME-BGC. BIOME-BGC will also be used within the context of a regional hydro-ecological simulation system (RHESSys) to generate landscape level estimates of 1994 daily hydrologic and carbon fluxes within the 1x10^6 km^2 boreas study region. A detailed description of the RHESSys model is given by Band et al. (1991 a,b, 1993)

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2. Investigator(s)

2.1 Investigator(s) Name and Title
Steven W. Running and John S. Kimball (TE-21 and RSS-8)
NTSG School of Forestry, University of Montana
Missoula, MT 59812

2.2 Title of Investigation
BIOME-BGC simulations of stand hydrology, productivity, surface-atmosphere carbon and water exchange at selected boreas tower flux sites for 1994

2.3 Contact Information

John S. Kimball
NTSG School of Forestry, University of Montana
Missoula, MT 59812
Tel: (406)243-5616
FAX: (406)243-4510
Email: johnk@ntsg.umt.edu

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3. Model Theory

See Section 1.5

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4. Equipment

BIOME-BGC is written in C with no specific hardware requirements.

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5. Data Acquisition Methods

The model requires a daily meteorological data file. This file consists of 6 columns that are space delimited with each row of the file representing a specific day of the year. Column 1 represents the day of year (Julian day format, 1-365), coelum 2 represents precipitation (cm), column 3 represents maximum 24 hr daily air temperature (C), column 4 represents minimum 24 hr daily air temperature (C), column 5 represents total daily solar radiation (direct+diffuse, kJ), column 6 represents the daylength (s). A second file is also required which defines site initialization parameters such as soil, litter, leaf and sapwood carbon pools, soil type and condition. A detailed discussion of the development of the tower site initialization parameter files is presented below.
BIOME-BGC requires general information about stand morphology and soil characteristics in order to simulate the water and carbon balance at a site. Information required by the model to define initial hydrologic characteristics of the study sites is given by Kimball et al. (submitted). A list of critical parameters used to define soil and stand carbon characteristics at the 8 study sites are presented in Table 1. These parameters were held constant throughout the model runs. Soil parameters were derived from measurements collected at the sites during 1994 by Cuenca et al. (submitted) and values reported in the literature for representative soil types (Hillel 1980). The soil depth was set at 0.5 m and assumed homogeneous in regard to soil mineralized carbon, structure and soil moisture characteristics. Mean daily stand solar albedos for snow-free conditions were estimated from site observations (Sellers et al. 1995).
Estimates of average annual leaf area index (LAI) were derived from effective LAI measurements conducted over approximately 3 periods during the 1994 growing season at each study site by Chen (submitted). Effective LAI was measured using LI-COR LAI-2000 plant canopy analyzer and adjusted for foliage clumping. Specific leaf area (SLA) and leaf nitrogen levels were determined from plucked needle and leaf measurements at the spruce, jack pine and aspen sites by Margolis et al. (1996 unpublished data). The amounts of leaf nitrogen in RuBisCO were estimated from the literature for representative cover types (Field and Mooney 1986). Leaf carbon was derived from LAI and SLA information. Sapwood carbon was estimated from sapwood biomass measurements collected by Gower et al. (1996 unpublished data) at the black spruce, aspen and jack pine sites, and estimates of the relative proportions of sapwood live cells (Waring and Schlesinger 1985). Coarse root carbon was estimated to be approximately 25% of sapwood carbon (e.g. Grier et al. 1981, Grier and Logan 1977).
The amount of carbon attributed to fine root biomass is highly variable depending on species type, stand age and nutrient availability. Processes governing the partitioning of carbon between root and foliar biomass are generally poorly understood and not well quantified in the literature. Observations have shown, however, that fine root biomass is generally greater than foliar biomass in nutrient limited systems which often occur in boreal and cold temperate forests and may represent an adaptation to maximize nutrient uptake (Nadelhoffer et al. 1985, Keyes and Grier 1981, Tetrealt et al. 1978). Soil carbon attributed to fine roots was estimated from 1.5 (SOAS) to 3.5 (SOJP) times the estimated leaf carbon based on observations from boreal and cold temperate coniferous and deciduous stands on nutrient poor sites (Gower et al. 1992, Comeau and Kimmins 1989, Nadelhoffer et al. 1985, Linder and Axelson 1982, Perala and Alban 1982, Keyes and Grier 1981). Soil litter and mineralized organic carbon pools within the prescribed 0.5 m soil depths were estimated from soil layer depth, bulk density and percent organic carbon measurements conducted at each of the study sites by Anderson et al. (1995 unpublished data).
Leaf, stem, coarse and fine root maintenance respiration coefficients were estimated from measured rates for coniferous and deciduous cover types (Sprugel et al. 1995). All other ecophysiological parameters were obtained from the literature for general cover types (e.g. Sprugel et al. 1995, Nobel 1991, Waring and Schlesinger 1985).

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6. Observations

6.1 Data Notes
Not Applicable

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7. Data Description

Air temperature, solar radiation and precipitation were measured at approximate 15 minute intervals at each of the study sites during 1994. These data were obtained from BOREAS principle investigators at each study site and the Saskatchewan Research Council's AMS mesonet database (BOREAS Science Team 1995). The 1994, meteorological records for each study site were incomplete due to periods of instrument malfunction, calibration and measurement inactivity. Continuous meteorological records for 1994 were obtained for each study site by temporally interpolating missing data or substituting data from adjacent sites. Daily maximum and minimum air temperatures, precipitation and solar radiation were then derived from the continuous data records for each site and used to generate model results.
BIOME-BGC was run over a 2 year period at each study site. The model was initialized using 1989 AMS mesonet station meteorological data from the Thompson airport (55.8 *N, 97.9 *W) for study sites in the NSA, and Prince Albert airport (53.2 *N, 105.7 *W) and Waskesiu Lake (53.9 *N, 106.1 *W) for study sites in the SSA (Shewchuk submitted). All analyses of model results were done for the second year using the 1994 meteorological database described above.

7.1 Spatial Characteristics

7.1.1 Spatial Coverage
These results constitute point simulations of the BOREAS NSA Old Black Spruce (NSA-OBS), Young Jack Pine (NSA-YJP), SSA Old Aspen (SSA-OA), Old Black Spruce (SSA-OBS), and Old Jack Pine (SSA-OJP) tower flux sites.

7.1.2 Spatial Coverage Map
Not Applicable

7.1.3 Spatial Resolution
Not Applicable

7.1.4 Projection
Not Applicable

7.1.5 Grid Description
Not Applicable

7.2 Temporal Characteristics
The model generated daily results for 2 years. Results for the first year were generated using 1989 meteorological data which were used to initialize the model, while all analyses were done for the second year (1994).

7.2.1 Temporal Coverage
01-01-1994 to 12-31-1994

7.2.2 Temporal Coverage Map NA
Not Applicable

7.2.3 Temporal Resolution
daily

7.3 Data Characteristics
BIOME-BGC requires an input daily meteorological data file and an initialization file to generate daily estimates of site hydrologic and carbon balance characteristics. The meteorological data file variables are described below. The initialization file provides site specific information about stand morphology, soil type and condition. The initialization files used to generate results for 1994 at the tower flux sites are included in this directory and are described in section 5.

7.3.1 Input Parameter/Variables
Meteorological data input file: DOY PCP TMAX TMIN SOLIN DAYLEN

7.3.2 Variable Description/Definition

DOY    = Julian day (1-365)
PCP    = daily precipitation (cm)
TMAX   = maximum 24-hour air temperature (C)
TMIN   = minimum 24-hour air temperature (C)
SOLIN  = total daily solar radiation (kJ)
DAYLEN = daylength (s)

7.3.3 Unit of Measurement
See 7.3.2

7.3.4 Data Source
Daily meteorological data were derived from approximate 15 minute measurements obtained from AMS mesonet and flux tower sites for 1994 (BOREAS Science Team 1995; Shewchuk submitted). The initialization data files were created using information obtained from measurements by other boreas investigators and the literature for similar stand types (See section 5).

7.3.5 Data Range
Not Applicable

7.4 Sample Data Record

7.4.1 Output Parameter/Variables
Hydrologic output variables:
DOY SNOWW SOILW T ET E Q

Carbon output variables:
DOY GPP Rdl Rnl Rsw Rcr Rfr Rh Rm Rg NPP NEE Rtot

**NOTE: NEE denoted with a (-) sign indicates net C release from the stand to the atmosphere while a positive sign indicates net C uptake by the stand.


7.4.2 Variable Description/Definition

DOY   = julian day (Day Of Year)
SNOWW = Snow water equivalent of the snowcover (mm)
SOILW = Water held in the soil layer (mm)
T     = Transpiration from the canopy (kg/m^2 day)
ET    = Evapotranspiration (kg/m^2 day)
E     = Evaporation from the canopy and surface (kg/m^2 day)
Q     = outflow (mm/day)
GPP   = Net daily photosynthesis (mg C/m^2 day)
Rdl   = Day-time leaf respiration (mg C/m^2 day)
Rnl   = Night leaf respiration (mg C/m^2 day)
Rsw   = Sapwood respiration (mg C/m^2 day)
Rcr   = Coarse root respiration (mg C/m^2 day)
Rfr   = Fine root respiration (mg C/m^2 day)
Rh    = Heterotrophic respiration (mg C/m^2 day)
Rm    = Maintenance respiration (mg C/m^2 day)
Rg    = Growth respiration (mg C/m^2 day)
NPP   = Net primary production (mg C/m^2 day)
NEE   = Net ecosystem carbon exchange (mg C/m^2 day); (-) sign indicates net C
        release to the atmosphere while a positive sign indicates net C uptake
        by the stand. Rtot=Total respiration (mg C/m^2 day)

7.4.3 Unit of Measurement
See section 7.4.2.

7.4.4 Data Source
BIOME-BGC model output

7.4.5 Data Range
Daily results for 1994

7.5 Sample Data Records

Meteorological data input file sample:

1 0.00 -28.50 -42.00 16.40 24467
2 0.00 -25.50 -42.40 28.70 24554
3 0.04 -15.70 -30.70 23.40 24649

Hydrologic output file:

DOY SNOWW SOILW T ET E Q
1 55.39 190.00 0.00 0.01 0.01 0.00
2 55.78 190.00 0.00 0.01 0.01 0.00
3 55.77 190.00 0.00 0.01 0.00 0.00

Carbon output file:

DOY GPP Rdl Rnl Rsw Rcr Rfr Rh Rm Rg NPP NEE Rtot
1 11 43 92 39 10 278 0 462 0.0 -451 -451 462
2 14 46 91 41 10 289 0 477 0.0 -463 -463 477
3 22 53 113 48 12 338 0 564 0.0 -542 -542 564

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8. Data Organization

8.1 Data Granularity
Not Applicable

8.2 Data Format(s)
The model input and output files are in ascii format with space separated columns.

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9. Data Manipulations

See Kimball et al. (Submitted), and Running and Hunt (1993) for detailed descriptions of model description, methods and processing steps.

9.1 Formulae
See section 9.

9.1.1 Derivation Techniques and Algorithms
See section 9.

9.2 Data Processing Sequence
See section 9.

9.2.1 Processing Steps
See section 9.

9.2.2 Processing Changes
See section 9.

9.3 Calculations
See section 9.

9.3.1 Special Corrections/Adjustments
Not Applicable

9.3.2 Calculated Variables
See section 7.4.1 and 7.4.2.

9.4 Graphs and Plots
Not Applicable

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10. Errors

10.1 Sources of Error
BIOME-BGC is a process level model designed to be general enough to apply at regional to global scales. The model uses several simplifying assumptions regarding stand and meteorological conditions in order to facilitate application at regional scales. A fundamental model assumption for this investigation was that stand physiological conditions such as age, stand structure, LAI and carbon storages were spatially and temporally uniform on an annual basis. Soil conditions such as depth, density and moisture content were also assumed spatially uniform with no lateral or subsurface drainage. Stand conditions at the study sites were both spatially and temporally diverse and were composed of different age types, biomass densities and species compositions (BOREAS Science Team 1995). Some sites also had significant vegetation understories that were not explicitly modeled in this investigation. Evidence suggests that these vegetation types contributed significantly to the daily carbon budget (e.g. Black et al. submitted). Further discussion of potential error sources for this investigation is given by Kimball et al. (1996 a,b submitted).

10.2 Quality Assessment
See section 10.1.

10.2.1 Model Validation by Source
Model results were compared with daily carbon and water fluxes derived from site tower flux measurements for 1994. Model estimates of annual NPP were also compared with NPP estimates derived from site biomass measurements and allometric equations for 1994 (BOREAS Science Team 1995). Model estimates of SNOWW and SOILW were compared with measured data for 1994 (BOREAS Science Team 1995). Detailed discussion of these comparisons are given by Kimball et al. (1996 a,b submitted).

10.2.2 Confidence Level/Accuracy Judgement
See section 10.2.1.

10.2.3 Measurement Error for Parameters
See section 10.1 and 10.2.1.

10.2.4 Additional Quality Assessments
See section 10.1 and 10.2.1.

10.2.5 Data Verification by Data Center

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11. Notes

11.1 Limitations of the Model
See section 10.1 and 10.2.1.

11.2 Known Problems with the Model
See section 10.1 and 10.2.1.

11.3 Usage Guidance
Not Applicable

11.4 Other Relevant Information
Not Applicable

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12. Application of the Model

These results represent research in progress. We expect our results to improve as additional measurement data regarding stand and soil morphology become available. These results are intended for comparison with other models and additional measurement data.

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13. Future Modifications and Plans

This model will be used in the context of RHESSys to generate landscape level estimates of daily and annual water and carbon exchange processes over the 1x106 km2 boreas grid at a 1 km2 spatial resolution.
Carbon allocation, growth respiration and nitrogen cycle routines will be activated (See Running and Hunt 1993) and model runs will be conducted over longer time periods (50 to several hundred years) to investigate the effects of inter-annual climate variations on site to regional water and carbon budgets.

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14. Software

BIOME-BGC was written in C code on a UNIX platform. To request a copy of the model please send email to the address in section 2.3.

14.1 Software Description
See section 14.

14.2 Software Access
See section 14.

14.3 Platform Limitations
See section 14.

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15. Data Access

15.1 Contact Information
See section 2.3

15.2 Data Center Identification

15.3 Procedures for Obtaining Data

15.4 Data Center Status/Plans
Not Applicable

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16. Output Products and Availability

16.1 Tape Products
Not Applicable

16.2 Film Products
Not Applicable

16.3 Other Products
Not Applicable

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17. References

Amthor, J.S. 1986. Evolution and applicability of a whole plant respiration model. Journal of Theoretical Biology. 122: 473-490.

Andren, O. and K. Paustian. 1987. Barley straw decomposition in the field: a comparison of models. Ecology. 68(5):1190-1200.

Black, T.A., G. den Hartog, H.H. Neumann, P.D. Blanken, P.C. Yang, C. Russell, Z. Nesic, X. Lee, S. G. Chen, and R. Staebler. 1995. Annual cycles of water vapour and carbon dioxide fluxes in and above a boreal aspen forest. Global Change Biology. Submitted.

Bonan, G.B., and H.H. Shugart. 1989. Environmental factors and ecological processes in boreal forests. Annual Review of Ecology and Systematics. 20:1-28.

BOREAS Science Team. 1995. Boreal Atmosphere-Ecosystem Study, Experimental Plan. Version 3.1, NASA/GSFC, Greenbelt, MD.

Chen, J.M. 1996. Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands. Agricultural and Forest Meteorology. In press.

Cole, D.W. and M. Rapp. 1981. Elemental cycling in forest ecosystems. In Dynamic Principles of Forest Ecosystems. Ed. D.E. Reichle. Cambridge University Press, London and New York, pp 341-409.

Comeau, P.G., and J.P. Kimmins. 1989. Above- and below-ground biomass and production of lodgepole pine on sites with differing soil moisture. Canadian Journal of Forest Res. 19:447-454.

Cosby, B.J., G.M. Hornberger, R.B. Clapp, and T.R. Ginn. 1984. A statistical exploration of the relationships of soil moisture characteristics to the physical properties of soils. Water Resources Research. 20(6):682-690.

Edwards, N.T., H.H. Shugart, S.B. McLaughlin, W.F. Harris, and D.E. Reichle. 1981. Carbon metabolism in terrestrial ecosystems. In InterBiol. Programme No. 23, "Dynamic Properties of Forest Ecosystems". Ed. D.E. Reichle. Cambridge University Press, London and New York, pp 499-536.

Evans, J.R. 1989. Photosynthesis and nitrogen relationships in leaves of C3 plants. Oecologia. 78:9-19.

Farquhar, G.D., S. von Caemmerer, and J.A. Berry. 1980. A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species. Planta. 149:78-90.

Farquhar, G.D. and S. von Caemmerer. 1982. Modelling of photosynthetic response to environmental conditions. In Encyclopedia of Plant Physiology, New Series, Vol. 12B, "Physiological Plant Ecology II". Eds. O.L. Lange, P.S. Nobel, C.B. Osmond, and H. Ziegler. Springer Verlag, Berlin, Germany, pp 549-587.

Farquhar, G.D. 1989. Models of integrated photosynthesis of cells and leaves. Phil. Trans. Roy. Soc. Lond. 323B:357-367.

Field, C. and H.A. Mooney. 1986. The photosynthesis-nitrogen relationship in wild plants. In On the Economy of Plant Form and Function. Ed. T.J. Givnish. Cambridge University Press, Cambridge, pp 25-55.

Fox, J.F. and K. Van Cleve. 1983. Relationships between cellulose decomposition, Jenny's k, forest-floor nitrogen, and soil temperature in Alaskan taiga forests. Canadian Journal of Forest Research. 13:789-794.

Gates, D.M. 1993. Plant-Atmosphere Relationships. Chapman and Hall, New York, 92 p.

Gower, S.T., K.A. Vogt, and C.C. Grier. 1992. Carbon dynamics of Rocky Mountain Douglas-fir: Influence of water and nutrient availability. Ecological Monographs. 62:43-65.

Grier, C.C. and R.S. Logan. 1981. Old-growth pseudotsuga menziesii communities of a western oregon watershed: biomass distribution and production budgets. Ecological Monographs. 47:373-400.

Grier, C.C., K.A. Vogt, M.R. Keyes, and R.L. Edmonds. 1981. Biomass distribution and above- and below-ground production in young and mature Abies amabilis zone ecosystems of the Washington Cascades. Canadian Journal of Forest Research. 11:155-157.

Hillel, D. 1980. Fundamentals of Soil Physics. Academic Press, New York, 413 p.

Hunt, R.E. and S.W. Running. 1992. Simulated dry matter yields for aspen and spruce stands in the North American boreal forest. Canadian Journal of Remote Sensing. 18(3):126-133.

Jarvis, P.G. and J.I.L. Morison. 1981. Stomatal control of transpiration and photosynthesis. In Stomatal Physiology. Eds. P.G. Jarvis and T.A. Mansfield. Cambridge University Press, Cambridge. pp 247-279.

Keyes, M.R., and C.C. Grier. 1981. Above- and below-ground net production in 40-year-old Douglas-fir stands on high and low productivity sites. Canadian Journal of Forest Res. 11:599-605.

Kimball, J.S., M.A. White and S.W. Running. 1996. BIOME-BGC simulations of BOREAS stand hydrologic processes. Journal of Geophysical Research. Submitted.

Kinerson, R.S., C.W. Ralston, and C.G. Wells. 1977. Carbon cycling in a loblolly pine plantation. Oecologia. 29:1-10.

Leuning, R. 1990. Modeling stomatal behavior and photosynthesis of Eucalyptus Grandis. Australian Journal of Plant Physiology. 17:159-175.

Linder, S., and B. Axelsson. 1982. Changes in carbon uptake and allocation patterns as a result of irrigation and fertilization in a young Pinus sylvestris stand. In "Carbon Uptake and Allocation: Key to Management of Subalpine Forest Ecosystems". Ed. R.H. Waring. International Union Forest Research Organization (IUFRO) Workshop, Forest Research Laboratory, Oregon State University, Corvallis, Oregon, pp 38-44.

Malkonen, E. 1974. Annual primary production and nutrient cycle in some Scots pine stands. Commun. Inst. For. Fenn. (Helsinki), No. 84.

Nadelhoffer, K.J., J.D. Aber, and J.M. Melillo. 1985. Fine root production in relation to total net primary production along a nitrogen mineralization gradient in temperate forests: a new hypothesis. Ecology. 66:1377-1390.

Nobel, P.S. 1991. Physicochemical and Environmental Plant Physiology. Academic Press Inc., New York, 635 p.

Orchard, V.A. and F.J. Cook. 1983. Relationship between soil respiration and soil moisture. Soil biology and Biochemistry. 15(4):447-453.

Paavilainen, E. 1980. Effect of fertilization on plant biomass and nutrient cycle on a drained dwarf shrub pine swamp. Comm. Inst. For. Fenn. (Helsinki), No. 98.

Penning de Vries, F.W.T., A. Brunsting, H.H. Van Laar. 1974. Products, requirements and efficiency of biosynthesis: A quantitative approach. Journal of Theoretical Biology. 45:339-377.

Perala, D.A. and D.H. Alban. 1982. Biomass, nutrient distribution and litterfall in Populus, Pinus and Picea stands on two different soils in Minnesota. Plant and Soil. 64:177-192.

Rastetter, E.B., A.W. King, B.J. Cosby, G.M. Hornberger, R.V. O'Neill, and J.E. Hobbie. 1992. Aggregating fine-scale ecological knowledge to model coarser-scale attributes of ecosystems. Ecological Applications. 2:55-70.

Running, S.W. and J.C. Coughlan. 1988. A general model of forest ecosystem processes for regional applications, I. hydrologic balance, canopy gas exchange and primary production processes. Ecological Modelling. 42:125-154.

Running, S.W. and R.E. Hunt. 1993. Generalization of a forest ecosystem process model for other biomes, BIOME-BGC, and an application for global-scale models. In Scaling Physiologic Processes: Leaf to Globe. Eds. J.R. Ehleringer and C.B. Field. Academic Press, San Diego, CA, pp 141-158.

Running, S.W., R.R. Nemani, and R.D. Hungerford. 1987. Extrapolation of synoptic meteorological data in mountainous terrain and its use for simulating forest evapotranspiration and photosynthesis. Canadian Journal of Forest Research 17:472-483.

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9):1549-1577.

Shewchuk, S.R. 1996. The surface atmospheric sciences mesonet for BOREAS. Journal of Geophysical Research. Submitted.

Sprugel, D.G., M.G. Ryan, J.R. Brooks, K.A. Vogt, and T.A. Martin. 1995. Respiration from the organ level to the stand. In Resource Physiology of Conifers, Acquisition, Allocation and Utilization. Eds. W.K. Smith and T.M. Hinckley. Academic Press, San Diego, pp 255-299.

Tetreault, J.P., B. Bernier, and J.A. Fortin. 1978. Nitrogen fertilization and mycorrhizae of balsam fir seedlings in natural stands. Naturaliste Canadien (Quebec). 105:461-466.

Waring, R.H. and W.H. Schlesinger. 1985. Forest Ecosystems Concepts and Management. Academic Press Inc., San Diego, 340 p.

Woodrow, I.E. and J.A. Berry. 1988. Enzymatic regulation of photosynthetic CO2 fixation in C3 plants. Annual Reviews of Plant Physiology and Plant Molecular Biology. 39:533-594.

Wullschleger, S.D. 1993. Biochemical limitations to carbon assimilation in C3 plants - a retrospective analysis of the A/Ci curves from 109 species. Journal of Experimental Botany. 44:907-920.

Zheng, D., E.R. Hunt and S.W. Running. 1993. A daily soil temperature model based on air temperature and precipitation for continental applications. Climate Research. 2:183-191.


17.1 Model Documentation
See Running and Coughlan (1988), Running and Hunt (1993), Hunt and Running (1992) and Kimball et al. (1996).

17.2 Journal Articles and Study Reports
See section 17.1.

17.3 Archive/DBMS Usage Documentation
Not Applicable

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18. Glossary of Terms

Not Applicable

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19. List of Acronyms

BOREAS  - BOReal Ecosystem-Atmosphere Study
BORIS   - BOREAS Information System
DAAC    - Distributed Active Archive Center
EOS     - Earth Observing System
EOSDIS  - EOS Data and Information System
GSFC    - Goddard Space Flight Center
NASA    - National Aeronautics and Space Administration
ORNL    - Oak Ridge National Laboratory
NSA     - BOREAS northern study area
SSA     - BOREAS southern study area
NOBS    - NSA old black spruce site
NYJP    - NSA young jack pine site
SOBS    - SSA old black spruce site
SOJP    - SSA old jack pine site
SOAS    - SSA old aspen site
URL     - Uniform Resource Locator
DOY     - julian day
SNOWW   - Snow water equivilent of the snowcover (mm)
SOILW   - Water held in the soil layer (mm)
T       - Transpiration from the canopy (kg/m^2 day)
ET      - Evapotranspiration (kg/m^2 day)
E       - Evaporation from the canopy and surface (kg/m^2 day)
Q       - outflow (mm/day)
GPP     - Net daily photosynthesis (mg C/m^2 day)
Rdl     - Day-time leaf respiration rate (mg C/m^2 day)
Rnl     - Night-time leaf respiration rate (mg C/m^2 day)
Rsw     - Sapwood respiration rate (mg C/m^2 day)
Rcr     - Coarse root respiration rate (mg C/m^2 day)
Rfr     - Fine root respiration rate (mg C/m^2 day)
Rm      - Maintenance respiration (mg C/m^2 day)
Rh      - Heterotrophic respiration (mg C/m^2 day)
Rg      - Growth respiration (mg C/m^2 day)
NPP     - Net primary production (mg C/m^2 day)
NEE     - Net ecosystem carbon exchange (mg C/m^2 day)
Rtot    - Total respiration (mg C/m^2 day)
PCP     - daily precipitation (cm)
TMAX    - maximum 24-hour air temperature (C)
TMIN    - minimum 24-hour air temperature (C)
SOLIN   - total daily solar radiation (kJ)
DAYLEN  - daylength (s)
LAI     - Leaf area index (m^2/m^2)
SLA     - Specific leaf area (m^2/kg C)

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20. Document Information

20.1 Document Revision Date
19-Sept-1996

20.2 Document Review Date(s)
BORIS Review:
Science Review:

20.3 Document
[BORIS and ORNL DAAC to fill in]

20.4 Citation
Use references in Section 17.1 when citing BIOME-BGC.

20.5 Document Curator
[BORIS and ORNL DAAC to fill in]

20.6 Document URL
[BORIS and ORNL DAAC to fill in]


Keywords: BIOME-BGC, carbon, water, hydrology, NPP, tower sites, modeling, productivity

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Last Updated: July 22, 1997