Photosynthesis is particularly difficult to quantify with remote sensing when changes in greenness are de-coupled from changes in carbon uptake. This is particularly relevant in evergreen needleleaf forests, which play a major role in the global carbon cycle and are highly sensitive to environmental change. We employ multi-scale observation frameworks to monitor photosynthesis in these (and other) systems. Specifically, we use proximal (tower-mounted) remote sensing instruments to disentangle physical from biological drivers of remotely sensed signals, ultimately improving our ability to monitor ecosystems and potential changes to their role in the global carbon budget.
Summary of ways to measure evergreen needleleaf forest photosynthesis from the molecular to ecosystem scale and data types highlighted in Pierrat et al., 2024. Bioscience.
Related Publications
Magney, T.S., Brissette, L.E.G., Pierrat, Z.A., Logan, B., Reblin, J., Nelson, S., Stutz, J., Frankenberg, C., Bowling, D.R., Wong, C.Y.S., 2025. Tracking subtle seasonal shifts in pigment composition with hyperspectral reflectance in a temperate evergreen forest. Tree Physiology tpaf108. https://doi.org/10.1093/treephys/tpaf108
Liu, H., Pierrat, Z. A., Dashti, H., Chen, M., 2025. Unrevealing site-dependent relationship between solar-induced chlorophyll fluorescence and gross primary productivity using the terrestrial ecosystem carbon cycle simulator. Remote Sensing of Environment 331, 115052. https://doi.org/10.1016/j.rse.2025.115052
Magney, T. S., & Pierrat, Z. A. 2025. Shifting equilibria in a warming boreal forest. Proceedings of the National Academy of Sciences, 122(3), e2424669122. https://doi.org/10.1073/pnas.2424669122
Pierrat, Z. A., Magney, T. S., Maguire, A., Brissette, L., Doughty, R., Bowling, D. R., Logan, B., Parazoo, N., Frankenberg, C., Stutz, J. 2024. Seasonal timing of fluorescence and photosynthetic yields at needle and canopy scales in evergreen needleleaf forests. Ecology, e4402. https://doi.org/10.1002/ecy.4402
*This paper has a photo gallery accompaniment at: Pierrat, Z. A., T. Magney, A. Maguire, L. Brissette, R. Doughty, D. R. Bowling, B. Logan, N. Parazoo, C. Frankenberg, and J. Stutz. 2024. Waking Before the Snow Melts: Detecting the Spring Transition in Evergreen Needleleaf Forests. Bull Ecol Soc Am 0(0):e02185. https://doi.org/10.1002/bes2.2185
Pierrat, Z. A., Magney, T. S., Cheng, R., Maguire, A. J., Wong, C. Y. S., Nehemy, M. F., Rao, M., *Nelson, S. E., *Williams, A. F., *Grosvenor, J. A. H., Smith, K. R., Reblin, J. S., Stutz, J., Richardson, A. D., Logan, B. A., & Bowling, D. R. 2024. The biological basis for using optical signals to track evergreen needleleaf photosynthesis. BioScience, biad116. https://doi.org/10.1093/biosci/biad116
Nehemy, M. F., Pierrat, Z., Maillet, J., Richardson, A. D., Stutz, J., Johnson, B., Helgason, W., Barr, A. G., Laroque, C. P., & McDonnell, J. J. 2023. Phenological assessment of transpiration: The stem-temp approach for determining start and end of season. Agricultural and Forest Meteorology, 331, 109319. https://doi.org/10.1016/j.agrformet.2023.109319
Pierrat, Z. A., Bortnik, J., Johnson, B., Barr, A., Magney, T., Bowling, D. R., Parazoo, N., Frankenberg, C., Seibt, U., & Stutz, J., 2022. Forests for forests: Combining vegetation indices with solar-induced chlorophyll fluorescence in random forest models improves gross primary productivity prediction in the boreal forest. Environmental Research Letters, 17(12), 125006. https://doi.org/10.1088/1748-9326/aca5a0
Cheng, R., Magney, T. S., Orcutt, E. L., Pierrat, Z., Köhler, P., Bowling, D. R., Bret-Harte, M. S., Euskirchen, E. S., Jung, M., Kobayashi, H., Rocha, A. V., Sonnentag, O., Stutz, J., Walther, S., Zona, D., & Frankenberg, C., 2022. Evaluating photosynthetic activity across Arctic-Boreal land cover types using solar-induced fluorescence. Environmental Research Letters, 17(11), 115009. https://doi.org/10.1088/1748-9326/ac9dae
Pierrat, Z., Magney, T., Parazoo, N. C., Grossmann, K., Bowling, D. R., Seibt, U., Johnson, B., Helgason, W., Barr, A., Bortnik, J., Norton, A., Maguire, A., Frankenberg, C., & Stutz, J., 2022. Diurnal and Seasonal Dynamics of Solar-Induced Chlorophyll Fluorescence, Vegetation Indices, and Gross Primary Productivity in the Boreal Forest. Journal of Geophysical Research: Biogeosciences, 127(2), e2021JG006588. https://doi.org/10.1029/2021JG006588
Nelson, P. R., Maguire, A. J., Pierrat, Z., Orcutt, E. L., Yang, D., Serbin, S., Frost, G. V., Macander, M. J., Magney, T. S., Thompson, D. R., Wang, J. A., Oberbauer, S. F., Zesati, S. V., Davidson, S. J., Epstein, H. E., Unger, S., Campbell, P. K. E., Carmon, N., Velez‐Reyes, M., & Huemmrich, K. F., 2022. Remote Sensing of Tundra Ecosystems Using High Spectral Resolution Reflectance: Opportunities and Challenges. Journal of Geophysical Research: Biogeosciences, 127(2). https://doi.org/10.1029/2021JG006697
Maguire, A. J., Eitel, J. U. H., Magney, T. S., Frankenberg, C., Köhler, P., Orcutt, E. L., Parazoo, N. C., Pavlick, R., & Pierrat, Z. A., 2021. Spatial covariation between solar-induced fluorescence and vegetation indices from Arctic-Boreal landscapes. Environmental Research Letters, 16(9), 095002. https://doi.org/10.1088/1748-9326/ac188a
Pierrat, Z., Nehemy, M. F., Roy, A., Magney, T., Parazoo, N. C., Laroque, C., Pappas, C., Sonnentag, O., Grossmann, K., Bowling, D. R., Seibt, U., *Ramirez, A., Johnson, B., Helgason, W., Barr, A., & Stutz, J. 2021. Tower-Based Remote Sensing Reveals Mechanisms Behind a Two-phased Spring Transition in a Mixed-Species Boreal Forest. Journal of Geophysical Research: Biogeosciences, 126(5), e2020JG006191. https://doi.org/10.1029/2020JG006191
Liu, H., Pierrat, Z. A., Dashti, H., Chen, M., 2025. Unrevealing site-dependent relationship between solar-induced chlorophyll fluorescence and gross primary productivity using the terrestrial ecosystem carbon cycle simulator. Remote Sensing of Environment 331, 115052. https://doi.org/10.1016/j.rse.2025.115052
Magney, T. S., & Pierrat, Z. A. 2025. Shifting equilibria in a warming boreal forest. Proceedings of the National Academy of Sciences, 122(3), e2424669122. https://doi.org/10.1073/pnas.2424669122
Pierrat, Z. A., Magney, T. S., Maguire, A., Brissette, L., Doughty, R., Bowling, D. R., Logan, B., Parazoo, N., Frankenberg, C., Stutz, J. 2024. Seasonal timing of fluorescence and photosynthetic yields at needle and canopy scales in evergreen needleleaf forests. Ecology, e4402. https://doi.org/10.1002/ecy.4402
*This paper has a photo gallery accompaniment at: Pierrat, Z. A., T. Magney, A. Maguire, L. Brissette, R. Doughty, D. R. Bowling, B. Logan, N. Parazoo, C. Frankenberg, and J. Stutz. 2024. Waking Before the Snow Melts: Detecting the Spring Transition in Evergreen Needleleaf Forests. Bull Ecol Soc Am 0(0):e02185. https://doi.org/10.1002/bes2.2185
Pierrat, Z. A., Magney, T. S., Cheng, R., Maguire, A. J., Wong, C. Y. S., Nehemy, M. F., Rao, M., *Nelson, S. E., *Williams, A. F., *Grosvenor, J. A. H., Smith, K. R., Reblin, J. S., Stutz, J., Richardson, A. D., Logan, B. A., & Bowling, D. R. 2024. The biological basis for using optical signals to track evergreen needleleaf photosynthesis. BioScience, biad116. https://doi.org/10.1093/biosci/biad116
Nehemy, M. F., Pierrat, Z., Maillet, J., Richardson, A. D., Stutz, J., Johnson, B., Helgason, W., Barr, A. G., Laroque, C. P., & McDonnell, J. J. 2023. Phenological assessment of transpiration: The stem-temp approach for determining start and end of season. Agricultural and Forest Meteorology, 331, 109319. https://doi.org/10.1016/j.agrformet.2023.109319
Pierrat, Z. A., Bortnik, J., Johnson, B., Barr, A., Magney, T., Bowling, D. R., Parazoo, N., Frankenberg, C., Seibt, U., & Stutz, J., 2022. Forests for forests: Combining vegetation indices with solar-induced chlorophyll fluorescence in random forest models improves gross primary productivity prediction in the boreal forest. Environmental Research Letters, 17(12), 125006. https://doi.org/10.1088/1748-9326/aca5a0
Cheng, R., Magney, T. S., Orcutt, E. L., Pierrat, Z., Köhler, P., Bowling, D. R., Bret-Harte, M. S., Euskirchen, E. S., Jung, M., Kobayashi, H., Rocha, A. V., Sonnentag, O., Stutz, J., Walther, S., Zona, D., & Frankenberg, C., 2022. Evaluating photosynthetic activity across Arctic-Boreal land cover types using solar-induced fluorescence. Environmental Research Letters, 17(11), 115009. https://doi.org/10.1088/1748-9326/ac9dae
Pierrat, Z., Magney, T., Parazoo, N. C., Grossmann, K., Bowling, D. R., Seibt, U., Johnson, B., Helgason, W., Barr, A., Bortnik, J., Norton, A., Maguire, A., Frankenberg, C., & Stutz, J., 2022. Diurnal and Seasonal Dynamics of Solar-Induced Chlorophyll Fluorescence, Vegetation Indices, and Gross Primary Productivity in the Boreal Forest. Journal of Geophysical Research: Biogeosciences, 127(2), e2021JG006588. https://doi.org/10.1029/2021JG006588
Nelson, P. R., Maguire, A. J., Pierrat, Z., Orcutt, E. L., Yang, D., Serbin, S., Frost, G. V., Macander, M. J., Magney, T. S., Thompson, D. R., Wang, J. A., Oberbauer, S. F., Zesati, S. V., Davidson, S. J., Epstein, H. E., Unger, S., Campbell, P. K. E., Carmon, N., Velez‐Reyes, M., & Huemmrich, K. F., 2022. Remote Sensing of Tundra Ecosystems Using High Spectral Resolution Reflectance: Opportunities and Challenges. Journal of Geophysical Research: Biogeosciences, 127(2). https://doi.org/10.1029/2021JG006697
Maguire, A. J., Eitel, J. U. H., Magney, T. S., Frankenberg, C., Köhler, P., Orcutt, E. L., Parazoo, N. C., Pavlick, R., & Pierrat, Z. A., 2021. Spatial covariation between solar-induced fluorescence and vegetation indices from Arctic-Boreal landscapes. Environmental Research Letters, 16(9), 095002. https://doi.org/10.1088/1748-9326/ac188a
Pierrat, Z., Nehemy, M. F., Roy, A., Magney, T., Parazoo, N. C., Laroque, C., Pappas, C., Sonnentag, O., Grossmann, K., Bowling, D. R., Seibt, U., *Ramirez, A., Johnson, B., Helgason, W., Barr, A., & Stutz, J. 2021. Tower-Based Remote Sensing Reveals Mechanisms Behind a Two-phased Spring Transition in a Mixed-Species Boreal Forest. Journal of Geophysical Research: Biogeosciences, 126(5), e2020JG006191. https://doi.org/10.1029/2020JG006191