William Kolby Smith

Interests

Teaching

Peer-to-peer learningtwo-way communicationGroup activitiesActive learning

Research

Remote SensingTerrestrial EcologyEnvironmental scienceCarbon and water cyclingBiogeochemistryEcological climatologyLand Use Change

Courses

Scholarly Contributions

Chapters

• Bastos, A., Bastos, A., Naipal, V., Naipal, V., Ahlstr\"om, A., Ahlstr\"om, A., MacBean, N., MacBean, N., Smith, W. K., Smith, W. K., Poulter, B., & Poulter, B. (2022). Semiarid ecosystems. In Balancing Greenhouse Gas Budgets(pp 311--335). Elsevier.

Journals/Publications

• Amaral, C. H., Brookshire, J., Calle, L., Campbell, P., Cawse‐Nicholson, K., Chlus, A., Currey, B., Huemmrich, F., Miller, C. E., Miner, K., Pierrat, Z., Poulter, B., Raiho, A. M., Schimel, D., Serbin, S., Shiklomanov, A. N., Smith, W. K., Stavros, N., Stutz, J., , Thompson, D. R., et al. (2023).

  Simulating global dynamic surface reflectances for imaging spectroscopy spaceborne missions ‐ LPJ‐PROSAIL

  . Journal of Geophysical Research: Biogeosciences, 128(1). doi:10.1029/2022jg006935
• Dannenberg, M. P., Barnes, M. L., Smith, W. K., Johnston, M. R., Meerdink, S. K., Wang, X., Scott, R. L., & Biederman, J. A. (2023). Upscaling dryland carbon and water fluxes with artificial neural networks of optical, thermal, and microwave satellite remote sensing. Biogeosciences, 20(2), 383--404.
• Fang, J., Gentine, P., Jeong, S., Litvak, M., Migliavacca, M., Russell, S., Smith, W. K., Wang, X., Zhang, Y., & Zhou, S. (2023).

  Satellite solar‐induced chlorophyll fluorescence tracks physiological drought stress development during 2020 southwest US drought

  . Global Change Biology. doi:10.1111/gcb.16683
• Li, Y., Zhang, W., Schwalm, C. R., Gentine, P., Smith, W. K., Ciais, P., Kimball, J. S., Gazol, A., Kannenberg, S. A., Chen, A., & others, . (2023). Widespread spring phenology effects on drought recovery of Northern Hemisphere ecosystems. Nature Climate Change, 1--7.
• Poulter, B., Currey, B., Calle, L., Shiklomanov, A. N., Amaral, C. H., Brookshire, J., Campbell, P., Chlus, A., Cawse-Nicholson, K., Huemmrich, F., & others, . (2023). Simulating global dynamic surface reflectances for imaging spectroscopy spaceborne missions-LPJ-PROSAIL. Journal of Geophysical Research: Biogeosciences, e2022JG006935.
• Anderson, J. L., Dashti, H., Fox, A. M., Hoar, T. J., Huo, X., MacBean, N., Moore, D. J., Roby, M., & Smith, W. K. (2022).

  Assimilation of Global Satellite Leaf Area Estimates Reduces Modeled Global Carbon Uptake and Energy Loss by Terrestrial Ecosystems

  . Journal of Geophysical Research: Biogeosciences, 127(8). doi:10.1029/2022jg006830
• Barnes, M. L., Biederman, J. A., Dannenberg, M. P., Duman, T., Johnston, M. R., Kimball, J. S., Knowles, J. F., Litvak, M. E., Scott, R. L., Smith, W. K., Wang, X., Williams, A. P., Yan, D., & Zhang, Y. (2022).

  Exceptional heat and atmospheric dryness amplified losses of primary production during the 2020 U.S. Southwest hot drought

  . Global Change Biology, 28(16), 4794-4806. doi:10.1111/gcb.16214
• Dannenberg, M. P., Barnes, M. L., Smith, W. K., Johnston, M. R., Meerdink, S. K., Wang, X., Scott, R. L., & Biederman, J. A. (2022). Upscaling dryland carbon and water fluxes with artificial neural networks of optical, thermal, and microwave satellite remote sensing. Biogeosciences Discussions, 1--33.
• Dannenberg, M. P., Yan, D., Barnes, M. L., Smith, W. K., Johnston, M. R., Scott, R. L., Biederman, J. A., Knowles, J. F., Wang, X., Duman, T., & others, . (2022). Exceptional heat and atmospheric dryness amplified losses of primary production during the 2020 US Southwest hot drought. Global change biology, 28(16), 4794--4806.
• Dashti, H., Smith, W. K., Huo, X., Fox, A. M., Javadian, M., Devine, C. J., Behrangi, A., & Moore, D. J. (2022). Underestimation of the impact of land cover change on the biophysical environment of the Arctic and boreal region of North America. Environmental Research Letters, 18(1), 014012.
• Fox, A. M., Huo, X., Hoar, T. J., Dashti, H., Smith, W. K., MacBean, N., Anderson, J. L., Roby, M., & Moore, D. J. (2022). Assimilation of global satellite leaf area estimates reduces modeled global carbon uptake and energy loss by terrestrial ecosystems. Journal of Geophysical Research: Biogeosciences, e2022JG006830.
• Hudson, A. R., Moore, D. J., Smith, W. K., & Trouet, V. (2022).

  Length of growing season is modulated by Northern Hemisphere jet stream variability

  . International Journal of Climatology, 42(11), 5644-5660. doi:10.1002/joc.7553
• Hudson, A. R., Smith, W. K., Moore, D. J., & Trouet, V. (2022). Length of growing season is modulated by Northern Hemisphere jet stream variability.. International Journal of Climatology.
• Javadian, M., Smith, W. K., Lee, K., Knowles, J. F., Scott, R. L., Fisher, J. B., Moore, D. J., Leeuwen, W. J., Barron-Gafford, G., & Behrangi, A. (2022). Canopy temperature is regulated by ecosystem structural traits and captures the ecohydrologic dynamics of a semiarid mixed conifer forest site. Journal of Geophysical Research: Biogeosciences, e2021JG006617.
• Roby, M., Scott, R. L., Biederman, J., Smith, W. K., & Moore, D. J. (2022). Response of soil carbon dioxide efflux to temporal repackaging of rainfall into fewer, larger events in a semiarid grassland. Frontiers in Environmental Science, 1782.
• Wang, X., Wang, X., Biederman, J. A., Biederman, J. A., Knowles, J. F., Knowles, J. F., Scott, R. L., Scott, R. L., Turner, A. J., Turner, A. J., Dannenberg, M. P., Dannenberg, M. P., K\"ohler, P., K\"ohler, P., Frankenberg, C., Frankenberg, C., Litvak, M. E., Litvak, M. E., Flerchinger, G. N., , Flerchinger, G. N., et al. (2022). Satellite solar-induced chlorophyll fluorescence and near-infrared reflectance capture complementary aspects of dryland vegetation productivity dynamics. Remote Sensing of Environment, 270, 112858.
• Zhang, F., Biederman, J. A., Pierce, N. A., Potts, D. L., Devine, C. J., Hao, Y., & Smith, W. K. (2022). Precipitation temporal repackaging into fewer, larger storms delayed seasonal timing of peak photosynthesis in a semi-arid grassland. Functional Ecology, 36(3), 646--658.
• Alkama, R., Berry, J. A., Campbell, J. E., Cescatti, A., Chen, J. M., Fernández-Martínez, M., Goll, D. S., He, W., Jain, A. K., Janssens, I. A., Ju, W., Kato, E., Kautz, M., Krüger, I., Lienert, S., Lombardozzi, D., Peñuelas, J., Poulter, B., Sanders, T. G., , Sardans, J., et al. (2021).

  Response to Comments on “Recent global decline of CO ₂ fertilization effects on vegetation photosynthesis”

  . Science, 373(6562). doi:10.1126/science.abg7484
• Biederman, J. A., Dannenberg, M. P., Reed, S. C., Smith, W. K., Yan, D., & Zhang, F. (2021).

  Five Decades of Observed Daily Precipitation Reveal Longer and More Variable Drought Events Across Much of the Western United States

  . Geophysical Research Letters, 48(7). doi:10.1029/2020gl092293
• Biederman, J. A., Devine, C. J., Hao, Y., Pierce, N. A., Potts, D. L., Smith, W. K., & Zhang, F. (2021).

  Precipitation temporal repackaging into fewer, larger storms delayed seasonal timing of peak photosynthesis in a semi‐arid grassland

  . Functional Ecology, 36(3), 646-658. doi:10.1111/1365-2435.13980
• Dannenberg, M. P., Smith, W. K., Zhang, Y., Song, C., Huntzinger, D. N., & Moore, D. J. (2021). Large-scale reductions in terrestrial carbon uptake following central Pacific El Ni\~no. Geophysical Research Letters, e2020GL092367.
• Gampe, D., Gampe, D., Zscheischler, J., Zscheischler, J., Reichstein, M., Reichstein, M., O’Sullivan, M., O’Sullivan, M., Smith, W. K., Smith, W. K., Sitch, S., Sitch, S., Buermann, W., & Buermann, W. (2021). Increasing impact of warm droughts on northern ecosystem productivity over recent decades. Nature Climate Change, 11(9), 772--779.
• Jiao, W., Wang, L., Smith, W. K., Chang, Q., Wang, H., & D’Odorico, P. (2021). Observed increasing water constraint on vegetation growth over the last three decades. Nature Communications, 12(1), 3777.
• Jiao, W., Wang, L., Smith, W. K., Chang, Q., Wang, H., & D’Odorico, P. (2021). Observed increasing water constraint on vegetation growth over the last three decades. Nature Communications, 12(1), 1--9.
• Norton, C. L., Dannenberg, M. P., Yan, D., Wallace, C. S., Rodriguez, J. R., Munson, S. M., Leeuwen, W. J., & Smith, W. K. (2021). Climate and socioeconomic factors drive irrigated agriculture dynamics in the lower Colorado river basin. Remote Sensing, 13(9), 1659.
• Walker, A. P., De, K., Bastos, A., Belmecheri, S., Georgiou, K., Keeling, R. F., McMahon, S. M., Medlyn, B. E., Moore, D. J., Norby, R. J., & others, . (2021). Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2. New Phytologist, 229(5), 2413--2445.
• Walker, A. P., De, K., Bastos, A., Belmecheri, S., Georgiou, K., Keeling, R. F., McMahon, S. M., Medlyn, B. E., Moore, D. J., Norby, R. J., & others, . (2021). Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2. New phytologist, 229(5), 2413--2445.
• Wang, S., Zhang, Y., Ju, W., Chen, J. M., Cescatti, A., Sardans, J., Janssens, I. A., Wu, M., Berry, J. A., Campbell, J. E., & others, . (2021). Response to Comments on “Recent global decline of CO2 fertilization effects on vegetation photosynthesis”. Science, 373(6562), eabg7484.
• Wang, S., Zhang, Y., Ju, W., Chen, J. M., Cescatti, A., Sardans, J., Janssens, I. A., Wu, M., Berry, J. A., Campbell, J. E., & others, . (2021). Response to Comments on “Recent global decline of CO2 fertilization effects on vegetation photosynthesis”. Science, 373(6562), eabg7484.
• Zhang, F., Biederman, J. A., Dannenberg, M. P., Yan, D., Reed, S. C., & Smith, W. K. (2021). Five decades of observed daily precipitation reveal longer and more variable drought events across much of the western United States. Geophysical Research Letters, 48(7), e2020GL092293.
• Zhang, F., Biederman, J. A., Pierce, N. A., Potts, D. L., Devine, C. J., Hao, Y., & Smith, W. K. (2021). Precipitation temporal repackaging into fewer, larger storms delayed seasonal timing of peak photosynthesis in a semi-arid grassland. Functional Ecology.
• Alkama, R., Berry, J. A., Campbell, E., Cescatti, A., Chen, J. M., Ciais, P., Fernández-Martínez, M., Friedlingstein, P., Goll, D. S., Haverd, V., He, W., Jain, A. K., Janssens, I. A., Ju, W., Kato, E., Kautz, M., Krüger, I., Lienert, S., Lombardozzi, D., , Peñuelas, J., et al. (2020).

  Recent global decline of CO ₂ fertilization effects on vegetation photosynthesis

  . Science, 370(6522), 1295-1300. doi:10.1126/science.abb7772
• Arora, V. K., Buermann, W., Friedlingstein, P., Haverd, V., Jain, A. K., Kato, E., Kautz, M., Lombardozzi, D., Nabel, J. E., O'Sullivan, M., Sitch, S., Smith, W. K., Tian, H., Vuichard, N., Wiltshire, A., & Zhu, D. (2020).

  Climate‐Driven Variability and Trends in Plant Productivity Over Recent Decades Based on Three Global Products

  . Global Biogeochemical Cycles, 34(12). doi:10.1029/2020gb006613
• Chen, M., Day, K. A., Del Grosso, S. J., Derner, J. D., Fuchs, B. A., Gao, W., Hartman, M. D., Lutz, S., Parton, W. J., Peck, D. E., Schulte, D. K., & Smith, W. K. (2020).

  Seasonal grassland productivity forecast for the U.S. Great Plains using Grass‐Cast

  . Ecosphere, 11(11). doi:10.1002/ecs2.3280
• Dannenberg, M. P., Didan, K., Jones, M. O., Kimball, J. S., Leeuwen, W. J., Moore, D. J., Smith, W. K., Wang, X., & Yan, D. (2020).

  Globally Consistent Patterns of Asynchrony in Vegetation Phenology Derived From Optical, Microwave, and Fluorescence Satellite Data

  . Journal of Geophysical Research: Biogeosciences, 125(7). doi:10.1029/2020jg005732
• Dannenberg, M., Wang, X., Yan, D., & Smith, W. K. (2020). Phenological characteristics of global ecosystems based on optical, fluorescence, and microwave remote sensing. Remote Sensing. doi:10.3390/rs12040671
• Hartman, M., Parton, W., Peck, D., Derner, J., Fuchs, B., & Smith, W. K. (2020). Seasonal Grassland Productivity Forecast for the U.S. Great Plains using Grass-Cast. Ecosphere. doi:10.1002/ecs2.3280
• Javadian, M., Berhangi, A., Smith, W. K., & Fisher, J. (2020). Global Trends in Evapotranspiration Dominated by Increases across Large Cropland Regions. Remote Sensing. doi:10.3390/rs12071221
• O'Sullivan, M., Smith, W. K., Sitch, S., Friedlingstein, P., Arora, V. K., Haverd, V., Jain, A. K., Kato, E., Kautz, M., Lombardozzi, D., Nabel, J. E., Tian, H., Vuichard, N., Wiltshire, A., Zhu, D., & Buermann, W. (2020). Climate-Driven Variability and Trends in Plant Productivity Over Recent Decades Based on Three Global Products. Global biogeochemical cycles, 34(12), e2020GB006613.
  More info

  Variability in climate exerts a strong influence on vegetation productivity (gross primary productivity; GPP), and therefore has a large impact on the land carbon sink. However, no direct observations of global GPP exist, and estimates rely on models that are constrained by observations at various spatial and temporal scales. Here, we assess the consistency in GPP from global products which extend for more than three decades; two observation-based approaches, the upscaling of FLUXNET site observations (FLUXCOM) and a remote sensing derived light use efficiency model (RS-LUE), and from a suite of terrestrial biosphere models (TRENDYv6). At local scales, we find high correlations in annual GPP among the products, with exceptions in tropical and high northern latitudes. On longer time scales, the products agree on the direction of trends over 58% of the land, with large increases across northern latitudes driven by warming trends. Further, tropical regions exhibit the largest interannual variability in GPP, with both rainforests and savannas contributing substantially. Variability in savanna GPP is likely predominantly driven by water availability, although temperature could play a role via soil moisture-atmosphere feedbacks. There is, however, no consensus on the magnitude and driver of variability of tropical forests, which suggest uncertainties in process representations and underlying observations remain. These results emphasize the need for more direct long-term observations of GPP along with an extension of in situ networks in underrepresented regions (e.g., tropical forests). Such capabilities would support efforts to better validate relevant processes in models, to more accurately estimate GPP.
• Wang, S., Zhang, Y., Ju, W., Chen, J. M., Ciais, P., Cescatti, A., Sardans, J., Janssens, I. A., Wu, M., Berry, J. A., Campbell, E., Fernández-Martínez, M., Alkama, R., Sitch, S., Friedlingstein, P., Smith, W. K., Yuan, W., He, W., Lombardozzi, D., , Kautz, M., et al. (2020). Recent global decline of CO fertilization effects on vegetation photosynthesis. Science (New York, N.Y.), 370(6522), 1295-1300.
  More info

  The enhanced vegetation productivity driven by increased concentrations of carbon dioxide (CO) [i.e., the CO fertilization effect (CFE)] sustains an important negative feedback on climate warming, but the temporal dynamics of CFE remain unclear. Using multiple long-term satellite- and ground-based datasets, we showed that global CFE has declined across most terrestrial regions of the globe from 1982 to 2015, correlating well with changing nutrient concentrations and availability of soil water. Current carbon cycle models also demonstrate a declining CFE trend, albeit one substantially weaker than that from the global observations. This declining trend in the forcing of terrestrial carbon sinks by increasing amounts of atmospheric CO implies a weakening negative feedback on the climatic system and increased societal dependence on future strategies to mitigate climate warming.
• Wang, X., & Smith, W. K. (2020). Globally consistent patterns of asynchrony in the phenology of optical, microwave, and fluorescence satellite data. Journal of Geophysical Research: Biogeosciences. doi:10.1029/2020JG005732
• Yang, J., Magney, T., Knowles, J., Yan, D., Smith, W. K., Scott, R., & Barron-Gafford, G. (2020). The photochemical reflectance index (PRI) captures the ecohydrologic sensitivity of a semi-arid mixed conifer forest. Journal of Geophysical Research: Biogeosciences. doi:10.1029/2019JG005624
• Arbuthnot, M., Brauman, K. A., Carlson, K. M., Gerber, J. S., Johnson, J. A., Milder, J. C., Nelson, E., Pennington, D. N., Polasky, S., Rozza, J. P., Siebert, S., Smith, W. K., & West, P. C. (2019).

  Voluntary sustainability standards could significantly reduce detrimental impacts of global agriculture

  . Proceedings of the National Academy of Sciences, 116(6), 2130-2137. doi:10.1073/pnas.1707812116
• Bastos, A., Ciais, P., Chevallier, F., Roedenbeck, C., Ballantyne, A. P., Maignan, F., Yin, Y. i., Fernandez-Martinez, M., Friedlingstein, P., Penuelas, J., Piao, S. L., Sitch, S., Smith, W. K., Wang, X., Zhu, Z., Haverd, V., Kato, E., Jain, A. K., Lienert, S., , Lombardozzi, D., et al. (2019). Contrasting effects of CO2 fertilization, land-use change and warming on seasonal amplitude of Northern Hemisphere CO2 exchange. ATMOSPHERIC CHEMISTRY AND PHYSICS, 19(19), 12361-12375.
• Bradley, B. A., Dahlin, K. M., Gough, C. M., Hoffman, F. M., M Fox, A., M Middleton, E., Serbin, S. P., Shiklomanov, A. N., Smallman, L., & Smith, W. K. (2019).

  Enhancing global change experiments through integration of remote‐sensing techniques

  . Frontiers in Ecology and the Environment, 17(4), 215-224. doi:10.1002/fee.2031
• Chen, M., Del Grosso, S. J., Derner, J. D., Gao, W., Hartman, M. D., Knapp, A. K., Lutz, S., Ojima, D. S., Parton, W. J., Schacht, W. H., Smith, W. K., Stephenson, M. B., Tucker, C. J., & Volesky, J. D. (2019).

  Assessing precipitation, evapotranspiration, and NDVI as controls of U.S. Great Plains plant production

  . Ecosphere, 10(10). doi:10.1002/ecs2.2889
• Chen, M., Parton, W. J., Hartman, M. D., Del, G. S., Smith, W. K., Knapp, A. K., Lutz, S., Derner, J., Tucker, C. J., Ojima, D. S., Volesky, J. D., Stephenson, M. B., Schacht, W. H., & Gao, W. (2019). Assessing precipitation, evapotranspiration, and NDVI as controls of US Great Plains plant production. ECOSPHERE, 10(10).
• Dannenberg, M. P., Smith, W. K., & Wise, E. K. (2019).

  Reduced tree growth in the semiarid United States due to asymmetric responses to intensifying precipitation extremes

  . Science Advances, 5(10). doi:10.1126/sciadv.aaw0667
• Dannenberg, M. P., Wise, E. K., & Smith, W. K. (2019). Reduced tree growth in the semiarid United States due to asymmetric responses to intensifying precipitation extremes. SCIENCE ADVANCES, 5(10).
• Dannenberg, M. P., Wise, E. K., & Smith, W. K. (2019). Reduced tree growth in the semiarid United States due to asymmetric responses to intensifying precipitation extremes. Science advances, 5(10), eaaw0667.
  More info

  Earth's hydroclimatic variability is increasing, with changes in the frequency of extreme events that may negatively affect forest ecosystems. We examined possible consequences of changing precipitation variability using tree rings in the conterminous United States. While many growth records showed either little evidence of precipitation limitation or linear relationships to precipitation, growth of some species (particularly those in semiarid regions) responded asymmetrically to precipitation such that tree growth reductions during dry years were greater than, and not compensated by, increases during wet years. The U.S. Southwest, in particular, showed a large increase in precipitation variability, coupled with asymmetric responses of growth to precipitation. Simulations suggested roughly a twofold increase in the probability of large negative growth anomalies across the Southwest resulting solely from 20th century increases in variability of cool-season precipitation. Models project continued increases in precipitation variability, portending future growth reductions across semiarid forests of the western United States.
• Fox, A. M., MacBean, N., Moore, D. J., Parazoo, N. C., & Smith, W. K. (2019).

  Constraining estimates of terrestrial carbon uptake: new opportunities using long‐term satellite observations and data assimilation

  . New Phytologist, 225(1), 105-112. doi:10.1111/nph.16055
• Levesque, M., Andreu-Hayles, L., Smith, W. K., Williams, A. P., Hobi, M. L., Allred, B. W., & Pederson, N. (2019). Tree-ring isotopes capture interannual vegetation productivity dynamics at the biome scale. NATURE COMMUNICATIONS, 10.
• Renwick, K. M., Fellows, A., Flerchinger, G. N., Lohse, K. A., Clark, P. E., Smith, W. K., Emmett, K., & Poulter, B. (2019). Modeling phenological controls on carbon dynamics in dryland sagebrush ecosystems. AGRICULTURAL AND FOREST METEOROLOGY, 274, 85-94.
• Shiklomanov, A. N., Bradley, B. A., Dahlin, K. M., Fox, A. M., Gough, C. M., Hoffman, F. M., Middleton, E. M., Serbin, S. P., Smallman, L., & Smith, W. K. (2019). Enhancing global change experiments through integration of remote-sensing techniques. FRONTIERS IN ECOLOGY AND THE ENVIRONMENT, 17(4), 215-224.
• Smith, W. K., Dannenberg, M. P., Yan, D., Herrmann, S., Barnes, M. L., Barron-Gafford, G. A., Biederman, J. A., Ferrenberg, S., Fox, A. M., Hudson, A., Knowles, J. F., MacBean, N., Moore, D., Nagler, P. L., Reed, S. C., Rutherford, W. A., Scott, R. L., Wang, X., & Yang, J. (2019). Remote sensing of dryland ecosystem structure and function: Progress, challenges, and opportunities. REMOTE SENSING OF ENVIRONMENT, 233.
• Smith, W. K., Fox, A. M., MacBean, N., Moore, D., & Parazoo, N. C. (2020). Constraining estimates of terrestrial carbon uptake: new opportunities using long-term satellite observations and data assimilation. NEW PHYTOLOGIST, 225(1), 105-112.
• Smith, W. K., Nelson, E., Johnson, J. A., Polasky, S., Milder, J. C., Gerber, J. S., West, P. C., Siebert, S., Brauman, K. A., Carlson, K. M., Arbuthnot, M., Rozza, J. P., & Pennington, D. N. (2019). Voluntary sustainability standards could significantly reduce detrimental impacts of global agriculture. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 116(6), 2130-2137.
• Yan, D., Scott, R. L., Moore, D., Biederman, J. A., & Smith, W. K. (2019). Understanding the relationship between vegetation greenness and productivity across dryland ecosystems through the integration of PhenoCam, satellite, and eddy covariance data. REMOTE SENSING OF ENVIRONMENT, 223, 50-62.
• Yu, K., Smith, W. K., Trugman, A. T., Condit, R., Hubbell, S. P., Sardans, J., Peng, C., Zhu, K., Penuelas, J., Cailleret, M., Levanic, T., Gessler, A., Schaub, M., Ferretti, M., & Anderegg, W. (2019). Pervasive decreases in living vegetation carbon turnover time across forest climate zones. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 116(49), 24662-24667.
• Yuan, W., Zheng, Y. i., Piao, S., Ciais, P., Lombardozzi, D., Wang, Y., Ryu, Y., Chen, G., Dong, W., Hu, Z., Jain, A. K., Jiang, C., Kato, E., Li, S., Lienert, S., Liu, S., Nabel, J., Qin, Z., Quine, T., , Sitch, S., et al. (2019). Increased atmospheric vapor pressure deficit reduces global vegetation growth. SCIENCE ADVANCES, 5(8).
• Yuan, W., Zheng, Y., Piao, S., Ciais, P., Lombardozzi, D., Wang, Y., Ryu, Y., Chen, G., Dong, W., Hu, Z., Jain, A. K., Jiang, C., Kato, E., Li, S., Lienert, S., Liu, S., Nabel, J. E., Qin, Z., Quine, T., , Sitch, S., et al. (2019). Increased atmospheric vapor pressure deficit reduces global vegetation growth. Science advances, 5(8), eaax1396.
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  Atmospheric vapor pressure deficit (VPD) is a critical variable in determining plant photosynthesis. Synthesis of four global climate datasets reveals a sharp increase of VPD after the late 1990s. In response, the vegetation greening trend indicated by a satellite-derived vegetation index (GIMMS3g), which was evident before the late 1990s, was subsequently stalled or reversed. Terrestrial gross primary production derived from two satellite-based models (revised EC-LUE and MODIS) exhibits persistent and widespread decreases after the late 1990s due to increased VPD, which offset the positive CO fertilization effect. Six Earth system models have consistently projected continuous increases of VPD throughout the current century. Our results highlight that the impacts of VPD on vegetation growth should be adequately considered to assess ecosystem responses to future climate conditions.
• Allred, B. W., Erickson, T. A., Jones, M. O., Moreno, A., Naugle, D. E., Robinson, N. P., Running, S. W., & Smith, W. K. (2018).

  Terrestrial primary production for the conterminous United States derived from Landsat 30 m and MODIS 250 m

  . Remote Sensing in Ecology and Conservation, 4(3), 264-280. doi:10.1002/rse2.74
• Anderson, J. L., Arellano, A. F., Fox, A. M., Hoar, T. J., Litvak, M. E., MacBean, N., Moore, D. J., Schimel, D. S., & Smith, W. K. (2018).

  Evaluation of a Data Assimilation System for Land Surface Models Using CLM4.5

  . Journal of Advances in Modeling Earth Systems, 10(10), 2471-2494. doi:10.1029/2018ms001362
• Barnes, M. L., Biederman, J. A., Fox, A. M., He, M., Hudson, A., Kimball, J. S., Litvak, M. E., MacBean, N., Moore, D. J., Scott, R. L., Smith, W. K., & Yan, D. (2018).

  Chlorophyll Fluorescence Better Captures Seasonal and Interannual Gross Primary Productivity Dynamics Across Dryland Ecosystems of Southwestern North America

  . Geophysical Research Letters, 45(2), 748-757. doi:10.1002/2017gl075922
• Buermann, W., Forkel, M., O'Sullivan, M., Sitch, S., Friedlingstein, P., Haverd, V., Jain, A. K., Kato, E., Kautz, M., Lienert, S., Lombardozzi, D. A., Nabel, J., Tian, H., Wiltshire, A. J., Zhu, D., Smith, W. K., & Richardson, A. D. (2018). Widespread seasonal compensation effects of spring warming on northern plant productivity. NATURE, 562(7725), 110-+.
• Buermann, W., Forkel, M., O'Sullivan, M., Sitch, S., Friedlingstein, P., Haverd, V., Jain, A. K., Kato, E., Kautz, M., Lienert, S., Lombardozzi, D., Nabel, J. E., Tian, H., Wiltshire, A. J., Zhu, D., Smith, W. K., & Richardson, A. D. (2018). Widespread seasonal compensation effects of spring warming on northern plant productivity. Nature, 562(7725), 110-114.
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  Climate change is shifting the phenological cycles of plants, thereby altering the functioning of ecosystems, which in turn induces feedbacks to the climate system. In northern (north of 30° N) ecosystems, warmer springs lead generally to an earlier onset of the growing season and increased ecosystem productivity early in the season. In situ and regional studies also provide evidence for lagged effects of spring warmth on plant productivity during the subsequent summer and autumn. However, our current understanding of these lagged effects, including their direction (beneficial or adverse) and geographic distribution, is still very limited. Here we analyse satellite, field-based and modelled data for the period 1982-2011 and show that there are widespread and contrasting lagged productivity responses to spring warmth across northern ecosystems. On the basis of the observational data, we find that roughly 15 per cent of the total study area of about 41 million square kilometres exhibits adverse lagged effects and that roughly 5 per cent of the total study area exhibits beneficial lagged effects. By contrast, current-generation terrestrial carbon-cycle models predict much lower areal fractions of adverse lagged effects (ranging from 1 to 14 per cent) and much higher areal fractions of beneficial lagged effects (ranging from 9 to 54 per cent). We find that elevation and seasonal precipitation patterns largely dictate the geographic pattern and direction of the lagged effects. Inadequate consideration in current models of the effects of the seasonal build-up of water stress on seasonal vegetation growth may therefore be able to explain the differences that we found between our observation-constrained estimates and the model-constrained estimates of lagged effects associated with spring warming. Overall, our results suggest that for many northern ecosystems the benefits of warmer springs on growing-season ecosystem productivity are effectively compensated for by the accumulation of seasonal water deficits, despite the fact that northern ecosystems are thought to be largely temperature- and radiation-limited.
• Dannenberg, M. P., Wise, E. K., Janko, M., Hwang, T., & Smith, W. K. (2018). Atmospheric teleconnection influence on North American land surface phenology. ENVIRONMENTAL RESEARCH LETTERS, 13(3).
• Dannenberg, M., Reed, S. C., Smith, W., Tucker, C., & Yan, D. (2018).

  Science at the frontier: multimethod research to evaluate ecosystem change across multiple scales

  . New Phytologist, 218(4), 1318-1320. doi:10.1111/nph.15195
• Fox, A. M., Hoar, T. J., Anderson, J. L., Arellano, A. F., Smith, W. K., Litvak, M. E., MacBean, N., Schimel, D. S., & Moore, D. (2018). Evaluation of a Data Assimilation System for Land Surface Models Using CLM4.5. JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS, 10(10), 2471-2494.
• Robinson, N. P., Allred, B. W., Smith, W. K., Jones, M. O., Moreno, A., Erickson, T. A., Naugle, D. E., & Running, S. W. (2018). Terrestrial primary production for the conterminous United States derived from Landsat 30 m and MODIS 250 m. Remote Sensing in Ecology and Conservation, 4(3), 264-280.
• Sloat, L. L., Gerber, J. S., Samberg, L. H., Smith, W. K., Herrero, M., Ferreira, L. G., Godde, C. M., & West, P. C. (2018). Increasing importance of precipitation variability on global livestock grazing lands. NATURE CLIMATE CHANGE, 8(3), 214-+.
• Smith, W. K. (2018). Distilling the role of ecosystem services in the Sustainable Development Goals. Ecological Indicators, 29, 70-82.
• Smith, W. K. (2018). Evidence of a robust relationship between solar-induced chlorophyll fluorescence and gross primary productivity across dryland ecosystems of southwestern North America. Geophysical Research Letters. doi:10.1002/2017GL075922
• Tucker, C., Yan, D., Dannenberg, M., Reed, S. C., & Smith, W. (2018). Science at the frontier: multimethod research to evaluate ecosystem change across multiple scales. NEW PHYTOLOGIST, 218(4), 1318-1320.
• Wood, S., Jones, S. K., Johnson, J. A., Brauman, K. A., Chaplin-Kramer, R., Fremier, A., Girvetz, E., Gordon, L. J., Kappel, C. V., Mandle, L., Mulligan, M., O'Farrell, P., Smith, W. K., Willemen, L., Zhang, W., & DeClerck, F. A. (2018). Distilling the role of ecosystem services in the Sustainable Development Goals. ECOSYSTEM SERVICES, 29, 70-82.
• Ballantyne, A., Smith, W., Anderegg, W., Kauppi, P., Sarmiento, J., Tans, P., Shevliakova, E., Pan, Y., Poulter, B., Anav, A., Friedlingstein, P., Houghton, R., & Running, S. (2017). Accelerating net terrestrial carbon uptake during the warming hiatus due to reduced respiration. NATURE CLIMATE CHANGE, 7(2), 148-+.
• Bell, T. W., Biederman, J. A., Bowling, D. R., Dore, S., Garatuza‐Payan, J., Goulden, M. L., Kolb, T. E., Krishnan, P., Krofcheck, D. J., Litvak, M. E., Maurer, G. E., Meyers, T. P., Oechel, W. C., Papuga, S. A., Ponce‐Campos, G. E., Rodriguez, J. C., Scott, R. L., Smith, W. K., Vargas, R., , Watts, C. J., et al. (2017).

  CO ₂ exchange and evapotranspiration across dryland ecosystems of southwestern North America

  . Global Change Biology, 23(10), 4204-4221. doi:10.1111/gcb.13686
• Biederman, J. A., Scott, R. L., Bell, T. W., Bowling, D. R., Dore, S., Garatuza-Payan, J., Kolb, T. E., Krishnan, P., Krofcheck, D. J., Litvak, M. E., Maurer, G. E., Meyers, T. P., Oechel, W. C., Papuga, S. A., Ponce-Campos, G. E., Rodriguez, J. C., Smith, W. K., Vargas, R., Watts, C. J., , Yepez, E. A., et al. (2017). CO2 exchange and evapotranspiration across dryland ecosystems of southwestern North America. GLOBAL CHANGE BIOLOGY, 23(10), 4204-4221.
• Chen, M., Day, K. A., Del Grosso, S. J., Derner, J. D., Gao, W., Hartman, M. D., Knapp, A. K., Ojima, D. S., Parton, W. J., Smith, W. K., & Tucker, C. J. (2017).

  The signature of sea surface temperature anomalies on the dynamics of semiarid grassland productivity

  . Ecosphere, 8(12). doi:10.1002/ecs2.2069
• Chen, M., Parton, W. J., Del, G., Hartman, M. D., Day, K. A., Tucker, C. J., Derner, J. D., Knapp, A. K., Smith, W. K., Ojima, D. S., & Gao, W. (2017). The signature of sea surface temperature anomalies on the dynamics of semiarid grassland productivity. ECOSPHERE, 8(12).
• Ciais, P., Lian, X., Liu, Y., Piao, S., & Smith, W. K. (2017).

  Seasonal Responses of Terrestrial Carbon Cycle to Climate Variations in CMIP5 Models: Evaluation and Projection

  . Journal of Climate, 30(16), 6481-6503. doi:10.1175/jcli-d-16-0555.1
• Dong, J., Liu, J., Lu, G., Oyler, J., Running, S., Smith, W. K., Wang, J., Yi, Y., & Zhao, M. (2017).

  Decreasing net primary production due to drought and slight decreases in solar radiation in China from 2000 to 2012: Decreasing NPP Due To Solar Radiation

  . Journal of Geophysical Research: Biogeosciences, 122(1), 261-278. doi:10.1002/2016jg003417
• Liu, Y., Piao, S., Lian, X. u., Ciais, P., & Smith, W. K. (2017). Seasonal Responses of Terrestrial Carbon Cycle to Climate Variations in CMIP5 Models: Evaluation and Projection. JOURNAL OF CLIMATE, 30(16), 6481-6503.
• Wang, J., Dong, J., Yi, Y., Lu, G., Oyler, J., Smith, W. K., Zhao, M., Liu, J., & Running, S. (2017). Decreasing net primary production due to drought and slight decreases in solar radiation in China from 2000 to 2012. JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES, 122(1), 261-278.
• Ahrestani, F. S., Hebblewhite, M., Post, E., Running, S., & Smith, W. K. (2016).

  Variation in stability of elk and red deer populations with abiotic and biotic factors at the species‐distribution scale

  . Ecology, 97(11), 3184-3194. doi:10.1002/ecy.1540
• Ahrestani, F. S., Smith, W. K., Hebblewhite, M., Running, S., & Post, E. (2016). Variation in stability of elk and red deer populations with abiotic and biotic factors at the species-distribution scale. ECOLOGY, 97(11), 3184-3194.
• Smith, W. K., Reed, S. C., Cleveland, C. C., Ballantyne, A. P., Anderegg, W., Wieder, W. R., Liu, Y. Y., & Running, S. W. (2016). Large divergence of satellite and Earth system model estimates of global terrestrial CO2 fertilization. NATURE CLIMATE CHANGE, 6(3), 306-310.
• Allred, B. W., Smith, W. K., Twidwell, D., Haggerty, J. H., Running, S. W., Naugle, D. E., & Fuhlendorf, S. D. (2015). Ecosystem services lost to oil and gas in North America. SCIENCE, 348(6233), 401-402.
• Allred, B. W., Smith, W. K., Twidwell, D., Haggerty, J. H., Running, S. W., Naugle, D. E., & Fuhlendorf, S. D. (2015). Sustainability. Ecosystem services lost to oil and gas in North America.. Science (New York, N.Y.), 348(6233), 401-2. doi:10.1126/science.aaa4785
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  Advanced technologies in oil and gas extraction coupled with energy demand have encouraged an average of 50,000 new wells per year throughout central North America since 2000. Although similar to past trends (see the graph, this page), the space and infrastructure required for horizontal drilling and high-volume hydraulic fracturing are transforming millions of hectares of the Great Plains into industrialized landscapes, with drilling projected to continue ( 1 , 2 ). Although this development brings economic benefits ( 3 ) and expectations of energy security, policy and regulation give little attention to trade-offs in the form of lost or degraded ecosystem services ( 4 ). It is the scale of this transformation that is important, as accumulating land degradation can result in continental impacts that are undetectable when focusing on any single region ( 5 ). With the impact of this transformation on natural systems and ecosystem services yet to be quantified at broad extents, decisions are being made with few data at hand (see the graph, this page).
• Anderegg, W., Ballantyne, A. P., Smith, W. K., Majkut, J., Rabin, S., Beaulieu, C., Birdsey, R., Dunne, J. P., Houghton, R. A., Myneni, R. B., Pan, Y., Sarmiento, J. L., Serota, N., Shevliakova, E., Tans, P., & Pacala, S. W. (2015). Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 112(51), 15591-15596.
• Cavaleri, M. A., Reed, S. C., Smith, W. K., & Wood, T. E. (2015). Urgent need for warming experiments in tropical forests. GLOBAL CHANGE BIOLOGY, 21(6), 2111-2121.
• Cleveland, C. C., Taylor, P., Chadwick, K. D., Dahlin, K., Doughty, C. E., Malhi, Y., Smith, W. K., Sullivan, B. W., Wieder, W. R., & Townsend, A. R. (2015). A comparison of plot-based satellite and Earth system model estimates of tropical forest net primary production. GLOBAL BIOGEOCHEMICAL CYCLES, 29(5), 626-644.
• Wieder, W. R., Cleveland, C. C., Smith, W. K., & Todd-Brown, K. (2015). Future productivity and carbon storage limited by terrestrial nutrient availability. NATURE GEOSCIENCE, 8(6), 441-444.
• Wieder, W. R., Cleveland, C. C., Smith, W. K., & Todd-Brown, K. (2015). Reply to 'Land unlikely to become large carbon source'. NATURE GEOSCIENCE, 8(12), 893-894.
• Hurley, M. A., Hebblewhite, M., Gaillard, J., Dray, S., Taylor, K. A., Smith, W. K., Zager, P., & Bonenfant, C. (2014). Functional analysis of Normalized Difference Vegetation Index curves reveals overwinter mule deer survival is driven by both spring and autumn phenology. PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 369(1643).
• Small, E. E., Larson, K. M., & Smith, W. K. (2014). Normalized Microwave Reflection Index: Validation of Vegetation Water Content Estimates From Montana Grasslands. IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING, 7(5), 1512-1521.
• Smith, W. K., Cleveland, C. C., Reed, S. C., & Running, S. W. (2014). Agricultural conversion without external water and nutrient inputs reduces terrestrial vegetation productivity. GEOPHYSICAL RESEARCH LETTERS, 41(2), 449-455.
• Sullivan, B. W., Smith, W. K., Townsend, A. R., Nasto, M. K., Reed, S. C., Chazdon, R. L., & Cleveland, C. C. (2014). Spatially robust estimates of biological nitrogen (N) fixation imply substantial human alteration of the tropical N cycle. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 111(22), 8101-8106.
• Wang, J., Dong, J., Liu, J., Huang, M., Li, G., Running, S. W., Smith, W. K., Harris, W., Saigusa, N., Kondo, H., Liu, Y., Hirano, T., & Xiao, X. (2014). Comparison of Gross Primary Productivity Derived from GIMMS NDVI3g, GIMMS, and MODIS in Southeast Asia. REMOTE SENSING, 6(3), 2108-2133.
• Cleveland, C. C., Houlton, B. Z., Smith, W. K., Marklein, A. R., Reed, S. C., Parton, W., Del, G., & Running, S. W. (2013). Patterns of new versus recycled primary production in the terrestrial biosphere. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 110(31), 12733-12737.
• Haberl, H., Erb, K., Krausmann, F., Running, S., Searchinger, T. D., & Smith, W. K. (2013). Bioenergy: how much can we expect for 2050?. ENVIRONMENTAL RESEARCH LETTERS, 8(3).
• Rout, M. E., Chrzanowski, T. H., Smith, W. K., & Gough, L. (2013). Ecological impacts of the invasive grass Sorghum halepense on native tallgrass prairie. BIOLOGICAL INVASIONS, 15(2), 327-339.
• Running, S. W., & Smith, W. K. (2012). Pushing the Planetary Boundaries Response. SCIENCE, 338(6113), 1420-1420.
• Smith, W. K., Cleveland, C. C., Reed, S. C., Miller, N. L., & Running, S. W. (2012). Bioenergy Potential of the United States Constrained by Satellite Observations of Existing Productivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 46(6), 3536-3544.
• Smith, W. K., Zhao, M., & Running, S. W. (2012). Global Bioenergy Capacity as Constrained by Observed Biospheric Productivity Rates. BIOSCIENCE, 62(10), 911-922.
• Smith, W. K., Gao, W., Steltzer, H., Wallenstein, M. D., & Tree, R. (2010). Moisture availability influences the effect of ultraviolet-B radiation on leaf litter decomposition. GLOBAL CHANGE BIOLOGY, 16(1), 484-495.

Proceedings Publications

• Biederman, J. A., Zhang, F., Pierce, N., Javadian, M., Devine, C. J., Potts, D. L., Roby, M., Reed, S., Hu, T., Dannenberg, M. P., & others, . (2022). RainMan: A Global Change Experiment Integrating Proximal Remote Sensing with Direct Measures of Semiarid Grassland Structure and Function. In Fall Meeting 2022.
• Dannenberg, M. P., Barnes, M., Smith, W. K., Johnston, M., Meerdink, S., Wang, X., Scott, R., Biederman, J., & Flerchinger, G. N. (2022). Upscaling dryland carbon and water fluxes with artificial neural networks of optical, thermal, and microwave remote sensing. In Fall Meeting 2022.
• Huo, X., Fox, A. M., Dashti, H., Devine, C. J., Anderson, J. L., Raczka, B. M., Smith, W. K., & Moore, D. J. (2022). Assimilating Leaf Area Index and Aboveground Biomass into the Community Land Model to Constrain Carbon Dynamics in the Arctic and Boreal Region. In Fall Meeting 2022.
• Johnston, M., Preisler, Y., Barnes, M., Smith, W. K., Biederman, J. A., Scott, R. L., & Dannenberg, M. P. (2022). Effects of Hot vs. Dry Vapor Pressure Deficit on Ecosystem Carbon and Water Fluxes. In Fall Meeting 2022.
• Smith, W. K., Wang, X., Dannenberg, M. P., Scott, R., Zhang, Y., Javadian, M., Biederman, J. A., & Reed, S. (2022). Multi-scale remote sensing of extreme drought impacts on vegetation productivity across drylands of the southwestern US. In Fall Meeting 2022.
• Dashti, H., Smith, W. K., Huo, X., Fox, A. M., Devine, C. J., & Moore, D. J. (2021). Comparing compositional and standard multivariate analyses of land cover data. In AGU Fall Meeting 2021.
• Dashti, H., Smith, W., Huo, X., Fox, A., Devine, C., & Moore, D. (2021). Comparing compositional and standard multivariate analyses of land cover data. In AGU Fall Meeting Abstracts, 2021.
• Devine, C. J., Smith, W. K., Huo, X., Fox, A. M., Dashti, H., & Moore, D. J. (2021). Enhancing retrieval of aboveground vegetation biomass over Alaska and northwestern Canada using remotely sensed vegetation optical depth and multispectral vegetation indices. In AGU Fall Meeting 2021.
• Devine, C., Smith, W., Huo, X., Fox, A., Dashti, H., & Moore, D. (2021). Enhancing retrieval of aboveground vegetation biomass over Alaska and northwestern Canada using remotely sensed vegetation optical depth and multispectral vegetation indices. In AGU Fall Meeting Abstracts, 2021.
• Gampe, D., Zscheischler, J., Reichstein, M., O'Sullivan, M., Smith, W. K., Sitch, S., & Buermann, W. (2021). Increased Drought Impact on Northern Ecosystem Productivity over the Past Decades. In AGU Fall Meeting 2021.
• Gampe, D., Zscheischler, J., Reichstein, M., O'Sullivan, M., Smith, W., Sitch, S., & Buermann, W. (2021). Increased Drought Impact on Northern Ecosystem Productivity over the Past Decades. In AGU Fall Meeting Abstracts, 2021.
• Hu, T., Biederman, J., Smith, W. K., Zeng, X., & Song, Y. (2021). The feedback of Arizona Grassland to Longer Seasonal Droughts and its Implication for Dryland Carbon Cycling: Insights from Model-Experiment Integration. In AGU Fall Meeting 2021.
• Hu, T., Biederman, J., Smith, W., Zeng, X., & Song, Y. (2021). The feedback of Arizona Grassland to Longer Seasonal Droughts and its Implication for Dryland Carbon Cycling: Insights from Model-Experiment Integration. In AGU Fall Meeting Abstracts, 2021.
• Huo, X., Fox, A. M., Hoar, T. J., Dashti, H., Devine, C. J., Smith, W. K., Anderson, J. L., & Moore, D. J. (2021). Data assimilation of LAI and biomass into CLM to constrain carbon dynamics in the Arctic and Boreal region. In AGU Fall Meeting 2021.
• Huo, X., Fox, A., Hoar, T., Dashti, H., Devine, C., Smith, W., Anderson, J., & Moore, D. (2021). Data assimilation of LAI and biomass into CLM to constrain carbon dynamics in the Arctic and Boreal region. In AGU Fall Meeting Abstracts, 2021.
• Javadian, M., Behrangi, A., Smith, W. K., & Fisher, J. B. (2021). Global Trends in Evapotranspiration Dominated by Increases across Large Cropland Regions: Insights into Sustainability in Food Production. In 101st American Meteorological Society Annual Meeting.
• Javadian, M., Lee, K., Smith, W., Behrangi, A., Knowles, J., Scott, R., Fisher, J., Moore, D., & Leeuwen, W. (2021). Diurnal Vegetation Water Stress Over a Semiarid Mixed Conifer Forest. In AGU Fall Meeting Abstracts, 2021.
• Javadian, M., San, L. K., Smith, W. K., Behrangi, A., Knowles, J. F., Scott, R. L., Fisher, J. B., Moore, D. J., & Leeuwen, W. (2021). Diurnal Vegetation Water Stress Over a Semiarid Mixed Conifer Forest. In AGU Fall Meeting 2021.
• Jiao, W., Wang, L., Smith, W. K., Chang, Q., Wang, H., & D'Odorico, P. (2021). Satellite observations revealed increasing water constraint on vegetation growth over the last 30 years. In AGU Fall Meeting 2021.
• Jiao, W., Wang, L., Smith, W., Chang, Q., Wang, H., & D'Odorico, P. (2021). Satellite observations revealed increasing water constraint on vegetation growth over the last 30 years. In AGU Fall Meeting Abstracts, 2021.
• Osborne, B., Adler, P., Dannenberg, M., Smith, W., Sala, O., Terry, T., Yan, D., Jordan, S., Ferrenberg, S., Lee, S., & others, . (2021). In hot deserts, drought is a stronger regulator of biogeochemistry over the short-term than physical disturbance. In AGU Fall Meeting Abstracts, 2021.
• Pervin, R., Reed, S., Smith, W., Yan, D., Mahmud, K., & Macbean, N. (2021). Novel Remote Sensing Approach for Estimating Biocrust Fractional Cover In Semiarid Ecosystems. In AGU Fall Meeting Abstracts, 2021.
• Reed, S., Smith, W., Gillan, J., & Villarreal, M. (2021). Remote sensing of biological soil crusts to understand and forecast soil health, stability, and contributions to climate. In AGU Fall Meeting Abstracts, 2021.
• Roby, M., Scott, R. L., Moore, D. J., Smith, W. K., & Biederman, J. (2021). Response of Soil Carbon Dioxide Efflux to Rainfall Intensification in a Semiarid Grassland. In AGU Fall Meeting 2021.
• Roby, M., Scott, R., Moore, D., Smith, W., & Biederman, J. (2021). Response of Soil Carbon Dioxide Efflux to Rainfall Intensification in a Semiarid Grassland. In AGU Fall Meeting Abstracts, 2021.
• Wang, X., Yan, D., Scott, R. L., Dannenberg, M. P., & Smith, W. K. (2021). Characterizing the response of photosynthesis, spectral reflectance, and sun-induced chlorophyll fluorescence to extreme drought at a semi-arid grassland site. In AGU Fall Meeting 2021.
• Wang, X., Yan, D., Scott, R., Dannenberg, M., & Smith, W. (2021). Characterizing the response of photosynthesis, spectral reflectance, and sun-induced chlorophyll fluorescence to extreme drought at a semi-arid grassland site. In AGU Fall Meeting Abstracts, 2021.
• Yu, K., Kulmatiski, A., Smith, W. K., & Smith, W. K. (2018). Vegetation Dynamics and Ecosystem Resilience Under Global Climate Change. In American Geophysical Union.
• Litvak, M. E., Fox, A. M., McBean, N., Barnes, M. L., Hudson, A. R., Yan, D., He, M., Kimball, J. S., Scott, R. L., Beiderman, J. A., Moore, D. J., & Smith, W. K. (2017, Dec). B44C-08: Evidence of a robust relationship between solar-induced chlorophyll fluorescence and gross primary productivity across dryland ecosystems of southwestern North America. In AGU Fall Meeting Proceedings.
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  Satellite remote sensing provides unmatched spatiotemporal information on multiple facets of vegetation dynamics including seasonal to interannual total photosynthesis, termed gross primary productivity (GPP). Yet, our understanding of the relationship between GPP and remote sensing observations - and how this relationship changes with scale, biophysical constraint, vegetation type, etc. - remains limited. This knowledge gap is especially apparent for dryland ecosystems, which have high spatial and temporal variability and are under-represented by long-term, continuous field measurements. Here, utilizing a new synthesis of eddy covariance flux tower data for southwestern North America, we present a first assessment of the ability of novel satellite remote sensing vegetation proxies to accurately capture seasonal to interannual GPP dynamics across the region. We evaluate the greenness-based Enhanced Vegetation Index (EVI) and emerging proxies linked to plant physiological function, Solar-Induced Fluorescence (SIF) and Photochemical Reflectivity Index (PRI). We find that SIF observations more consistently correlate with seasonal GPP dynamics (R = 0.90) compared to EVI (R = 0.85) and PRI (R = 0.78). More, we find that SIF observations are also more sensitive to interannual GPP variability (linear slope = 0.80) relative to EVI (linear slope = 0.63) and PRI (linear slope = 0.35). This is likely due to increased sensitivity of SIF to GPP during periods of decoupling between greenness and photosynthesis due to water-limitation / stomatal closure. Conversely, EVI and PRI observations better capture spatial GPP variability between flux tower sites. These results suggest that combinations of these independent vegetation growth proxies could yield synergistic improvements in satellite-based GPP estimates.
• Ballantyne, A. P., White, J. W., Tans, P. P., Smith, W. K., Miller, J. B., Bowling, D. R., & Anderegg, W. R. (2014). Diagnosing Carbon-Climate Feedbacks in the Contemporary Carbon Cycle. In American Geophysical Union.

Presentations

• Fox, A. M., Smith, W. K., Hoar, T., & Moore, D. J. (2017, Dec). B43I-03: Initializing carbon cycle predictions from the Community Land Model by assimilating global biomass observations (Invited). AGU Fall Meeting Proceedings.
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  The locations and longevity of terrestrial carbon sinks remain uncertain, however it is clear that in order to predict long-term climate changes the role of the biosphere in surface energy and carbon balance must be understood and incorporated into earth system models (ESMs). Aboveground biomass, the amount of carbon stored in vegetation, is a key component of the terrestrial carbon cycle, representing the balance of uptake through gross primary productivity (GPP), losses from respiration, senescence and mortality over hundreds of years.The best predictions of current and future land-atmosphere fluxes are likely from the integration of process-based knowledge contained in models and information from observations of changes in carbon stocks using data assimilation (DA). By exploiting long times series, it is possible to accurately detect variability and change in carbon cycle dynamics through monitoring ecosystem states, for example biomass derived from vegetation optical depth (VOD), and use this information to initialize models before making predictions.To make maximum use of information about the current state of global ecosystems when using models we have developed a system that combines the Community Land Model (CLM) with the Data Assimilation Research Testbed (DART), a community tool for ensemble DA. This DA system is highly innovative in its complexity, completeness and capabilities.Here we described a series of activities, using both Observation System Simulation Experiments (OSSEs) and real observations, that have allowed us to quantify the potential impact of assimilating VOD data into CLM-DART on future land-atmosphere fluxes. VOD data are particularly suitable to use in this activity due to their long temporal coverage and appropriate scale when combined with CLM, but their absolute values rely on many assumptions. Therefore, we have had to assess the implications of the VOD retrieval algorithms, with an emphasis on detecting uncertainty due to assumptions and inputs in the algorithms that are incompatible with those encoded within CLM. It is probable that VOD describes changes in biomass more accurately than absolute values, so in additional to sequential assimilation of observations, we have tested alternative filter algorithms, and assimilating VOD anomalies.
• MacBean, N., Scott, R. L., Beiderman, J. A., Vulchard, N., Hudson, A., Barnes, M., Smith, W. K., Peylin, P. P., Maignan, F., & Moore, D. J. (2017, Dec). GC21C-0953: CMIP5 land surface models systematically underestimate inter-annual variability of net ecosystem exchange in semi-arid southwestern North America.. AGU Fall Meeting Proceedings.
• Smith, W. K. (2019, Characterizing and Monitoring Land Change and Associated Ecosystem Responses Using Long-term Time Series Remote Sensing Data). Improved understanding of land cover and land use change impacts on ecosystem functioning using high spatiotemporal resolution satellite observations. AGU Annual Meeting 2019. San Francisco, CA.
• Smith, W. K. (2019, Organized Oral Session: Cutting-Edge Remote Sensing Applications in Ecology: Spanning Scales, Sensors, and Systems.). Monitoring photosynthesis from leaf to canopy using high frequency measurements of chlorophyll fluorescence and photochemical reflectivity from near-surface remote sensing platforms.. Ecological Society of America annual meeting 2019.
• Smith, W. K. (2019, Session: Detecting carbon-climate feedback processes IV.). Constraining the terrestrial CO2 fertilization effect using satellite observations: Challenges and Opportunities. American Geophysical Union Chapman Conference 2019. San Diego, CA.
• Smith, W. K., Cinthia, N., Yan, D., Van Leeuwen, W. J., & et al, . (2019, Dec). Improved understanding of land cover and land use change impacts on ecosystem functioning using high spatiotemporal resolution satellite observations. AGU, San Francisco.
• Yan, D., Scott, R. L., Moore, D. J., Beiderman, J. A., & Smith, W. K. (2017, Dec). GC21F-0997: Understanding the relationship between vegetation phenology and productivity across key dryland ecosystem types through the integration of PhenoCam, satellite, and eddy covariance data. AGU Fall Meeting Proceedings.
• Smith, W. K., Didan, K., Van Leeuwen, W. J., Moore, D. J., Kimball, J., Jones, M., Dannenberg, M., Yang, D., & Wang, X. (2018, 12). B54C-07 Comparisons of Global Land Surface Phenology Derived from Vegetation Greenness, Optical Depth, and Solar-induced Chlorophyll Fluorescence. American Geophysical Union. Washington DC.
• Smith, W. K., Arellano, A. F., Barnes, M. L., Hudson, A. R., Montane, F., Fox, A. M., & Moore, D. J. (2017, Aug). Combining models and data to understand vegetation function across timescales. 102nd Annual Meeting of the Ecological Society of America. Portland, OR: ESA.

Poster Presentations

• Gallery, R. E., Smith, W. K., Muscarella, C., Jong, E., Raub, H., Jimenez, J., Gallery, R. E., Smith, W. K., Muscarella, C., Jong, E., Raub, H., & Jimenez, J. (2017, Dec). Soil Microbial Activity Responses to Fire in a Semi-arid Savannah Ecosystem Pre- and Post-Monsoon Season. American Geophysical Union (AGU). New Orleans, LA: AGU.