References

Biogeosciences

1726-4189

Copernicus Publications

Göttingen, Germany

10.5194/bg-4-597-2007

Scaling net ecosystem production and net biome production over a heterogeneous region in the western United States

Turner

D. P.

¹ Ritts

W. D.

¹ Law

B. E.

¹ Cohen

W. B.

² Yang

¹ Hudiburg

¹ Campbell

J. L.

¹ Duane

Forest Science Department, Oregon State University, Corvallis OR 97331, USA

USDA Forest Service, PNW Station, Corvallis OR 97331, USA

06 08 2007

4 4 597 612

2007

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/

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The full text article is available as a PDF file from https://bg.copernicus.org/articles/4/597/2007/bg-4-597-2007.pdf

Bottom-up scaling of net ecosystem production (NEP) and net biome production (NBP) was used to generate a carbon budget for a large heterogeneous region (the state of Oregon, 2.5×105 km2) in the western United States. Landsat resolution (30 m) remote sensing provided the basis for mapping land cover and disturbance history, thus allowing us to account for all major fire and logging events over the last 30 years. For NEP, a 23-year record (1980–2002) of distributed meteorology (1 km resolution) at the daily time step was used to drive a process-based carbon cycle model (Biome-BGC). For NBP, fire emissions were computed from remote sensing based estimates of area burned and our mapped biomass estimates. Our estimates for the contribution of logging and crop harvest removals to NBP were from the model simulations and were checked against public records of forest and crop harvesting. The predominately forested ecoregions within our study region had the highest NEP sinks, with ecoregion averages up to 197 gC m−2 yr−1. Agricultural ecoregions were also NEP sinks, reflecting the imbalance of NPP and decomposition of crop residues. For the period 1996–2000, mean NEP for the study area was 17.0 TgC yr−1, with strong interannual variation (SD of 10.6). The sum of forest harvest removals, crop removals, and direct fire emissions amounted to 63% of NEP, leaving a mean NBP of 6.1 TgC yr−1. Carbon sequestration was predominantly on public forestland, where the harvest rate has fallen dramatically in the recent years. Comparison of simulation results with estimates of carbon stocks, and changes in carbon stocks, based on forest inventory data showed generally good agreement. The carbon sequestered as NBP, plus accumulation of forest products in slow turnover pools, offset 51% of the annual emissions of fossil fuel CO2 for the state. State-level NBP dropped below zero in 2002 because of the combination of a dry climate year and a large (200 000 ha) fire. These results highlight the strong influence of land management and interannual variation in climate on the terrestrial carbon flux in the temperate zone.

References 1

Acker, S. A., Halpern, C. B., Harmon, M. E., and Dyrness, C. T.: Trends in bole biomass accumulation, net primary production and tree mortality in \textitPsuedotsuga menziesii forest of contrasting age, Tree Physiol., 22, 213–217, 2002.

Alerich, C. L., Klevgard, L., Liff, C., and Miles, P. D.: The Forest Inventory and Analysis Database: Database Description and Users Guide Version 1.7, USDA Forest Service, North Central Research Station, NC-218, 193 pp., 2004.

Alig, R. and Butler, B.: Forest cover changes in the United States: 1952–1997, with projections to 2050, USDA Forest Service, Portland Oregon, PNW-GTR-613, 106 pp., 2004.

Alig, R. J., Krankina, O. N., Yost, A., and Kuzminykh, J.: Forest carbon dynamics in the Pacific Northwest (USA) and the St. Petersburg region of Russia: Comparisons and policy implications, Clim. Change, 79, 335–360, 2006.

Anthoni, P. M., Freibauer, A., Kolle, O., and Schultze, E.-D.: Winter wheat exchange in Thuringia, Germany, Agr. Forest Meteorol., 121, 55–67, 2004.

Azuma, D. L., Dunham, P. A., and Veneklase, B. A.: Timber Resource Statistics of Eastern Oregon, 1999, Resource Bulletin PNW-RB-238, USDA Forest Service, PNW Research Station, Portland OR, 42 pp. 2004.

Azuma, D. L., Hiserote, B., and Dunham, P. A.: The Western Juniper Resource of Eastern Oregon, U.S. Department of Agriculture, Pacific Northwest Research Station, PNW-RB-249, 18 pp., 2005.

Bachelet, D., Neilson, R. P., Lenihan, J. M., and Drapek, R. J.: Climate change effects on vegetation distribution and carbon budget in the United States, Ecosystems, 4, 164–185, 2001.

Baker, D. F., Law, R. M., Gurney, K. R., Rayner, P., Peylin, P., Denning, A. S., Bousquet, P., Bruhwiler, L., Chen, Y. H., Ciais, P., Fung, I. Y., Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., and Zhu, Z.: TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO2 fluxes, 1988–2003, Global Biogeochem. Cy., 20, GB1002, https://doi.org/10.1029/2004GB002439, 2006, 2006.

Bell, J. L. and Sloan, L. C.: CO2 sensitivity of extreme climate events in the western United States, Earth Interact., 10, Paper 15, 1–17, 2006.

Bousquet, P., Peylin, P., Ciais, P., Quere, C. L., Friedlingstein, P., and Tans, P. P.: Regional changes in carbon dioxide fluxes of land and oceans since 1980, Science, 290, 1342–1346, 2000.

Brown, R. T., Agee, J. K., and Franklin, J. F.: Forest restoration and fire: principles in the context of place, Conserv. Biol., 18, 903–912, 2004.

Campbell, J. L., Sun, O. J., and Law, B. E.: Disturbance and net ecosystem production across three climatically distinct forest landscapes, Global Biogeochem. Cy., 18, GB4017, https://doi.org/10.1029/2004GB002236, 2004.

Campbell, J. L., Law, B. E., and Donato, D.: Carbon emissions from the Biscuit Fire, J.Geophys. Res.-Bio., in press, 2007.

Campbell, S., Azuma, D. L., and Weyermann, D.: Forests of Western Oregon: an Overview, USDA Forest Service, PNW Station, Portland, OR, General Technical Report, PNW-GTR-525, 27 pp., 2002.

Ceinciala, E. and Tatarinov, F. A.: Application of BIOME-BGC model to managed forests. 2. Comparison with long-term observations of stand production for major tree species, Forest Ecol. Manage., 237, 252–266, 2006.

Chen, J. M., Paw U, K. T., Ustin, S. L., Suchanek, T. H., Bond, B. J., Brosofske, K. D., and Falk, M.: Net ecosystem exchanges of carbon, water, and energy in young and old-growth Douglas-fir forests, Ecosystems, 7, 534–544, 2004.

Chojnacky, D. C. and Heath, L. S.: Estimating down deadwood from FIA forest inventory variables in Maine, Environ. Pollut., 116, 243–248, 2002.

Cohen, W. B., Harmon, M. E., Wallin, D. O., and Fiorella, M.: Two decades of carbon flux from forests of the Pacific Northwest, BioScience, 46, 836–844, 1996.

Cohen, W. B., Spies, T. A., Alig, R. J., Oetter, D. R., Maiersperger, T. K., and Fiorella, M.: Characterizing 23 years (1972–95) of stand replacement disturbance in western Oregon forests with Landsat imagery, Ecosystems, 5, 122–137, 2002.

Cohen, W. B., Spies, T. A., and Fiorella, M.: Estimating the age and structure of forests in a multi-ownership landscape of western Oregon, USA, Int. J. Remote Sens., 16, 721–746, 1995.

CONUS: Conterminous United States multi-layer soil characteristics data set for regional climate and hydrology modeling, http://www.soilinfo.psu.edu/index.cgi?soil_data&conus, 2007.

DAYMET: Distributed climate data, http://www.daymet.org/, 2006.

DeBell, D. S. and Franklin, J. F.: Old-growth Douglas-fir and western hemlock: a 36-year record of growth and mortality, West. J. Appl. For., 2, 111–114, 1987.

Diffenbaugh, N. S., Sloan, L. C., Snyder, M. A., Bell, J. L., Kaplan, J., Shafer, S. L., and Bartlein, P. J.: Vegetation sensitivity to global anthropogenic carbon dioxide emissions in a topographically complex region, Global Biogeochem. Cy., 17, 1067, https://doi.org/10.1029/2002/GB001974, 2003.

EPA: Inventory of U.S. Greenhouse Gas Emissions and Sinks:1990-2004, USEPA #430-R-06-002, http://www.epa.gov/climatechange/emissions/usinventoryreport.htm, 2006.

FIA: U.S. Department of Agriculture Forest Inventory and Analysis Program, http://fia.fs.fed.us, 2006.

Garman, S. L., Swanson, F. J., and Spies, T. A.: Past, present, future landscape patterns in the Douglas-fir region of the Pacific Northwest, in: Forest Fragmentation: Wildlife and Management Implications, edited by: Rochelle, J. A., Lehmann, L. A., and Wisniewski, J., Brill Academic Publishing, The Netherlands, 61–86, 1999.

Gedney, D. R., Azuma, D. L., Bolsinger, C. L., and McKay, N.: Western Juniper in Eastern Oregon, PNW-GTR-464, U.S. Department of Agriculture, Forest Service Pacific Northwest Research Station, Portland, OR, 53 pp., 1999.

Gholz, H. L.: Environmental limits on above ground net primary production, leaf area, and biomass in vegetation zones of the Pacific Northwest, Ecology, 63, 469–481, 1982.

Harmon, M. E., Harmon, J. M., Ferrell, W. K., and Brooks, D.: Modeling carbon stores in Oregon and Washington forest products: 1900–1992, Climatic Change, 33, 521–550, 1996.

Hasenauer, H., Merganicova, K., Petritsch, R., Pietsch, S. A., and Thornton, P. E.: Validating daily climate interpolations over complex terrain in Austria, Agric. Forest Meteorol., 119, 87–107, 2003.

Healey, S. P., Cohen, W. B., Yang, Z., and Krankina, O. N.: Comparison of Tasseled Cap-based Landsat data structures for use in forest disturbance detection, Rem. Sens. Environ., 97, 301–310, 2005.

Healey, S. P., Yang, Z., Cohen, W. B., and Pierce, D. J.: Application of two regression-based methods to estimate the effects of partial harvest on forest structure using Landsat data, Rem. Sens. Environ., 101, 115–126, 2006.

Hicke, J. A., Jenkins, J. C., Ojima, D. S., and Ducey, M.: Spatial patterns of forest characteristics in the western United States derived from inventories, Ecol. Appl., in press, 2007.

Homann, P. S., Sollins, P., Fiorella, M., Thorson, T., and Kern, J. S.: Regional soil organic carbon storage estimates for western Oregon by multiple approaches, Soil Sci. Soc. Am. J., 62, 789–796, 1998.

Houghton, R. A., Hackler, J. L., and Lawrence, K. T.: The U.S. carbon budget: contribution from land use change, Science, 285, 574–578, 1999.

Hurtt, G. C., Dubayah, R., Drake, J., Moorcraft, P. R., Pacala, S. W., Balir, J. B., and Fearon, M. G.: Beyond potential vegetation: combining lidar data and a height-structured model for carbon studies, Ecol. Appl., 14, 873–883, 2004.

Janssens, I. A., Freibauer, A., Ciais, P., Smith, P., Nabuurs, G.-J., Folberth, G., Schlamadinger, B., Hutjes, R. W. A., Ceulemans, R., Schulze, E.-D., Valentini, R., and Dolman, A. J.: Europe's terrestrial biosphere absorbs 7 to 12% of European anthropogenic CO2 emissions, Science, 300, 1538–1542, 2003.

Kagan, J. S., Hak, J. C., Csuti, B., Kiilsgaurd, C. W., and Gaines, E. P.: Oregon Gap Analysis Project Final Report: A geographic approach to planning for biological diversity, 1999.

Karstens, U., Gloor, M., Heimann, M., and Rodenbeck, C.: Insights from simulations with high-resolution transport and process models on sampling of the atmosphere for constraining midlatitude land carbon sinks, J. Geophys. Res.-Atmos., 111, D12301, https://doi.org/10.1029/2005JD006278, 2006.

Kauppi, P. E., Mielikainen, K., and Kuusela, K.: Biomass and carbon budget of European forests, 1971–1990, Science, 256, 70–74, 1992.

Kern, J. S., Turner, D. P., and Dodson, R. F.: Spatial patterns in soil organic carbon pool size in the Northwestern United States, in: Soil Processes and the Carbon Cycle, edited by: Lal, R., Kimbal, J. M., Follett, R., and Stewart, B. A., CRC Press, Boca Raton, FL, 29–43, 1998.

Korner, C.: Slow in, rapid out – carbon flux studies and Kyoto targets, Science, 300, 1242–1243, 2003.

Lagergren, F., Grelle, A., Lankreijer, H., Molder, M., and Lindroth, A.: Current carbon balance of the forested area in Sweden and its sensitivity to global change as simulated by Biome-BGC, Ecosystems, 9, 894–908, 2006.

Law, B. E., Turner, D., Campbell, J., Van Tuyl, S., Ritts, W. D., and Cohen, W. B.: Disturbance and climate effects on carbon stocks and fluxes across Western Oregon USA, Global Change Biol., 10, 1429–1444, 2004.

Law, B. E., Turner, D. P., Lefsky, M., Campbell, J., Guzy, M., Sun, O., VanTuyl, S., and Cohen, W. B.: Carbon fluxes across regions: observational constraints at multiple scales, in: Scaling and Uncertainity Analysis in Ecology: Methods and Applications, edited by: Wu, J., Jones, K. B., Li, H., Loucks, O. L., Columbia University Press, New York, 167–190, 2006.

Law, B. E., Waring, R. H., Anthoni, P. M., and Aber, J. D.: Measurements of gross and net ecosystem productivity and water vapor exchange of a \textitPinus \textitponderosa ecosystem, and an evaluation of two generalized models, Global Change Biol., 6, 155–168, 2000.

Lefsky, M. A., Harding, D. J., Keller, M., Cohen, W. B., Carabajal, C. C., Espirito-Santo, F. D. B., Hunter, M. O., and de Oliveira, R.: Estimates of forest canopy height and aboveground biomass using ICESat, Geophys. Res. Lett., 32, L22S02, https://doi.org/10.1029/2005GL023971, 2005, 2005.

Lennartz, S.: Oregon Forest Land Change Mapping, Sanborn Mapping Solutions, Portland, OR, 2005.

Leung, L. R., Qian, Y., and Bian, X.: Midcentury ensemble regional climate change scenarios for the western United States, Clim. Change, 62, 75–113, 2004.

Loveland, T. R. and Merchant, J. M.: Ecoregions and ecoregionalization: geographical and ecological perspectives, Environ. Manage., https://doi.org/10.1007/s00267-003-5181-x, 2004.

Lovett, G. M., Cole, L. L., and Pace, M. L.: Is net ecosystem production equal to ecosystem carbon accumulation?, Ecosystems, 9, 152–155, 2006.

Lutz, J. A. and Halpern, C. B.: Tree mortality during early forest development: a long term study of rates, causes, and consequences, Ecol. Monogr., 76, 257–275, 2006.

Miller, D. A. and White, R. A.: A Conterminous United States Multi-Layer Soil Characteristics Data Set for Regional Climate and Hydrology Modeling, Earth Interactions, 2 (available online at http://EarthInteractions.org), 1998.

Mills, J. R. and Zhou, X.: Projecting national forest inventories for the 2000 RPA timber assessment, 58 pp. 2003.

Moeur, M., Spies, T. A., Hemstrom, M., Martin, J. R., Alegria, J., Browning, J., Cissel, J., Cohen, W. B., Demeo, T. E., Healey, S. P., and Warbington, R.: Northwest Forest Plan – The First Ten Years (1994–2003): Status and Trend of Late-Successional and Old-Growth Forests, USDA Forest Service, Pacific Northwest Research Station, Portland OR, PNW-GTR 649, 142 pp., 2005.

Morgenstern, K., Black, T. A., Humphreys, E. R., Griffis, T. J., Drewitt, G. B., Cai, T., Nesic, Z., Spittlehouse, D. L., and Livingston, N. J.: Sensitivity and uncertainty of the carbon balance of a Pacific Northwest Douglas-fir forest during an ElNino/LaNina cycle, Agr. Forest Meteorol., 123, 201–219, 2004.

Mote, P. W.: Trends in temperature and precipitation in the Pacific Northwest during the twentieth century, Northwest Sci., 77, 271–282, 2003.

Moureaux, C., Debacq, A., Bodson, B., Heinesch, B., and Aubinet, M.: Annual net ecosystem carbon exchange by a sugar beet crop, Agric. Forest Meteorol., 139, 25–39, 2006.

NOAA: National Oceanic and Atmospheric Administration, http://www.cmdl.noaa.gov/ccgg/carbontracker, 2007.

NWCC: Northwest Interagency Coordination Center, 2004 Annual Intelligence Report, available at http://www.nwccweb.us/admin/publications.asp, 2004.

Obrist, D., Delucia, D. H., and Arnone, J. A.: Consequences of wildfire on ecosystem CO2 and water vapour fluxes in the Great Basin, Global Change Biol., 9, 563–574, 2003.

ODE: Report on reducing Oregon's greenhouse gas emissions, Oregon Department of Energy, http://oregon.gov/ENERGY/GBLWRM/Draft_Intro.shtml, 2003.

ODF: Oregon Department of Forestry, Complete Harvest Data 1962-Present, http://www.odf.state.or.us/DIVISIONS/resource_policy/resource_planning/Annual_Reports/, 2006.

Ogle, S. M., Breidt, F. J., and Paustian, K.: Bias and variance in model results associated with spatial scaling of measurements for parameterization in regional assessments, Global Change Biol., 12, 1–8, 2006.

Ohmann, J. L. and Gregory, M. J.: Predictive mapping of forest composition and structure with direct gradient analysis and nearest-neighbor imputation in coastal Oregon, USA, Can. J. For. Res., 32, 725–741, 2002.

Omernik, J. M.: Ecoregions of the conterminous United States. Map (scale 1:7 500 000), Ann. Assoc. Am. Geogr., 77, 118–125, 1987.

Pacala, S. W., Hurtt, G. C., Baker, D., Peylin, P., Houghton, R. A., Birdsey, R. A., Heath, L. S., Sundquist, E. T., Stallard, R. F., Ciais, P., Moorcroft, P., Caspersen, J. P., Shevliakova, E., Moore, B., Kohlmaier, G., Holland, E. A., Gloor, M., Harmon, M. E., Fan, S.-M., Sarmiento, J. L., Goodale, C. L., Schimel, D., and Field, C. B.: Consistent land- and atmosphere-based U.S. carbon sink estimates, Science, 292, 2316–2322, 2001.

Paw U, K. T., Falk, M., Suchanek, T. H., Ustin, S. L., Chen, J., Park, Y., Winner, W. E., Thomas, S. C., Hsiao, T. C., Shwa, R. H., King, T. S., Pyles, R. D., Schroeder, M., and Matista, A. A.: Carbon dioxide exchange between an old-growth forest and the atmosphere, Ecosystems, 7, 513–524, 2004.

Pietsch, S. A. and Hasenauer, H.: Evaluating the self-initialization procedure for large-scale ecosystem models, Global Change Biol., 12, 1658–1669, 2006.

Pietsch, S. A., Hasenauer, H., and Thornton, P. E.: BGC-model parameters for tree species growing in central European forests, Forest Ecol. Manag., 211, 264–295, 2005.

Potter, C., Klooster, S., Nemani, R., Genovese, V., Hiatt, S., Fladeland, M., and Gross, P.: Estimating carbon budgets for U.S. ecosystems, EOS, 87, 1–3, 2006.

Reichstein, M., Ciais, P., Papale, D., Valentini, R., Running, S., Viovy, N., Cramer, W., Granier, A., Ogee, J., Allard, V., Aubinet, M., Bernhofer, C., Buchmann, N., Carrara, A., Grunwald, T., Heimann, M., Heinesch, B., Knohl, A., Kutsch, W., Loustau, D., Manca, G., Matteucci, G., Miglietta, F., Ourcival, J. M., Pilegaard, K., Pumpanen, J., Rambal, S., Schaphoff, S., Seufert, G., Soussana, J. F., Sanz, M. J., Vesala, T., and Zhao, M.: Reduction of ecosystem productivity and respiration during the European summer 2003 climate anomaly: a joint flux tower, remote sensing and modelling analysis, Global Change Biol., 12, 1–18, 2006. Reichstein, M., Papale, D., Valentini, R., Aubinet, M., Bernhofer, C., Knohl, A., Laurila, T., Lindroth, A., Moors, E., Pilegaard, K., and Seufert, G.: Determinants of terrestrial ecosystem carbon balance inferred from European eddy covariance sites, Geophys. Res. Lett., 34, L01402, https://doi.org/10.1029/2006GL, 2007.

Sapsis, D. B. and Kaufmann, J. B.: Fuel consumption and fire behavior associated with prescribed fires in sagebrush ecosystems, Northwest Sci., 65, 173–179, 1991.

Schimel, D., Melillo, J., Tian, H., McGuire, A. D., Kicklighter, D., Kittel, T., Rosenbloom, N., Running, S., Thornton, P., Ojima, D., Parton, W., Kelly, R., Sykes, M., Neilson, R., and Rizzo, B.: Contribution of increasing CO2 and climate to carbon storage by ecosystems in the United States, Science, 287, 2004–2006, 2000.

Schulze, E.-D., Wirth, C., and Heimann, M.: Managing forests after Kyoto, Science, 289, 2058–2059, 2000.

Smith, J. E. and Heath, L. S.: Carbon stocks and projections on public forestlands in the United States, 1952–2040, Environ. Manage., 33, 433–442, 2004.

Smith, W. B., Miles, P. D., Vissage, J. S., and Pugh, S. A.: Forest Resources of the United States, 2002, GTR-NC-241, U.S.D.A. Forest Service, North Central Research Station, St. Paul MI., 2004.

Smithwick, E. A. H., Harmon, M. E., Remillard, S. M., Acker, S. A., and Franklin, J. F.: Potential upper bounds of carbon stores in forests of the Pacific Northwest, Ecol. Appl., 12, 1303–1317, 2003.

Tatarinov, F. A. and Cienciala, E.: Application of BIOME-BGC model to managed forests. 1. Sensitivity analysis, Forest Ecol. Manag., 237, 267–279, 2006.

Thornton, P. E., Hasenauer, H., and White, M. A.: Simultaneous estimation of daily solar radiation and humidity from observed temperature and precipitation: an application over complex terrain in Austria, Agric. Forest Meteorol., 104, 255–271, 2000.

Thornton, P. E., Law, B. E., Gholz, H. L., Clark, K. L., Falge, E., Ellsworth, D. S., Goldstein, A. H., Monson, R. K., Hollinger, D., Falk, M., Chen, J., and Sparks, J. P.: Modeling and measuring the effects of disturbance history and climate on carbon and water budgets in evergreen needleleaf forests, Agric. Forest Meteorol., 113, 185–222, 2002.

Thornton, P. E. and Running, S. W.: An improved algorithm for estimating incident daily solar radiation from measurements of temperature, humidity, and precipitation, Agric. Forest Meteorol., 93, 211–228, 1999.

Thornton, P. E., Running, S. W., and White, M. A.: Generating surfaces of daily meteorological variables over large regions of complex terrain, J. Hydrol., 190, 214–251, 1997.

Turner, D. P., Cohen, W. B., and Kennedy, R. E.: Alternative spatial resolutions and estimation of carbon flux over a managed forest landscape in Western Oregon, Landscape Ecol., 15, 441–452, 2000.

Turner, D. P., Guzy, M., Lefsky, M., Ritts, W., VanTuyl, S., and Law, B. E.: Monitoring forest carbon sequestration with remote sensing and carbon cycle modeling, Environ. Manage., 4, 457–466, 2004.

Turner, D. P., Guzy, M., Lefsky, M.A., Van Tuyl, S., Sun, O., Daly, C., Law. B.E.: Effects of land use and fine-scale environmental heterogeneity on net ecosystem production over a temperate coniferous forest landscape, Tellus B, 55, 657–668, 2003.

Turner, D. P., Koerper, G. J., Harmon, M. E., and Lee, J. J.: A carbon budget for forests of the conterminous United States, Ecol. Appl., 5, 421–436, 1995.

UNFCCC: United Nations Framework Convention on Climate Change. http://www.unfccc.de/resource/conv/index.html, 1992.

USDA: National Agricultural Statistics Service, Published Estimates Database 2001, http://www.nass.usda.gov/index.asp, 2001.

Van Tuyl, S., Law, B. E.,Turner, D. P., and Gitelman, A. I.: Variability in net primary production and carbon storage in biomass across forests – an assessment integrating data from forest inventories, intensive sites, and remote sensing, For. Ecol. Manage., 209, 273–291, 2005

Vogelmann, J. E., Howard, S. M., Yang, L., Larson, C. R., Wylie, B. K., and Van Driel, N.: Completion of the 1990s National Land Cover Data Set for the conterminous United States from Landsat Thematic Mapper data and ancillary data sources, Photogramm. Eng. Rem. S., 67, 650–652, 2001.

Waddell, K. L. and Hiserote, B.: The PNW-FIA Integrated Database User Guide and Documentation: Version 2.0, Forest Inventory and Analysis Program, Pacific Northwest Research Station, Portland, OR, 2005.

Wallin, D. O., Harmon, M. E., and Cohen, W. B.: Modeling regional-scale carbon dynamics in Pacific Northwest Forests, in: Carbon Dynamics of Two Forest Regions: Northwestern Russian and the Pacific Northwest, edited by: Krankina, O. and Harmon, M. E., Springer-Verlag, New York, in press, 2007.

Waring, R. H. and Franklin, J. F.: Evergreen forests of the Pacific Northwest, Science, 204, 1380–1386, 1979.

Westerling, A. L., Hidalgo, H. G., Cayan, D. R., and Swetnam, T. W.: Warming and earlier spring increases western U.S. forest wildfire activity, Science, 313, 940–943, 2006.

White, M. A., Thornton, P. E., Running, S. W., and Nemani, R. R.: Parameterization and sensitivity analysis of the BIOME-BGC terrestrial ecosystem model: net primary production controls, Earth Interact., 4, 1–85, 2000.

Woodward, F. I., Lomas, M. R., and Lee, S. E.: Predicting the future productivity and distribution of global terrestrial vegetation, in: Terrestrial Global Productivity, edited by: Roy, J., Saugier, B., and Mooney, A., Academic Press, San Diego, CA, 519–539, 2001.