Project Funding: 2015 - 2020

NRA: 2014 NASA: Terrestrial Ecology   

Funded by NASA

Abstract:
At 13,400 km in length, the Forest Tundra Ecotone (FTE) is the worldÃÆ'Æ'Ã'Æ'ÃÆ'ââ'¬ Ã''ÃÆ'Æ'Ã'ââ'¬ ''ÃÆ'Æ'Ã'Æ'ÃÆ'ââ'¬ Ã''''s largest ecological transition zone. However, little is known about how the FTE - a critical component of the ABoVE study domain - will respond to ever-increasing environmental change. Remotely sensed information could play a key role in filling portions of this critical knowledge gap, yet relatively little remote sensing work has been conducted to link the current structural status of the FTE with dynamic changes in its ecological function. The overarching objective of the proposed study is to integrate LiDAR, passive spectral, and tree ecophysiological data to link biophysical structure to ecological function in the FTE. In so doing, we will be able to remotely assess the vulnerability and resilience of the FTE to environmental change. To characterize FTE structure, we will use LiDAR to create standardized baseline data at multiple locations within the FTE of the ABoVE study domain, and benchmark our results relative to the existing FTE-wide map developed by Ranson et al. (2011) using MODIS and Landsat. We will establish transects at FTE sites in Alaska and Canada to study how LiDAR derived surface and canopy micro-structure affect: (1) air and soil temperature, (2) snowpack dynamics (via hyper-temporal terrestrial LiDAR), (3) net radiation throughout the FTE canopy and on the FTE floor (via a radiative transfer model parametrized using structural information from LiDAR), and (4) plant function (via the use of ground-based radiometers coupled with ecophysiological measurements). By using statistical modeling approaches, these datasets will allow us to determine mechanistic relationships among FTE structure, physical growth environment, and plant function at fine spatial scale, where critical changes in individual tree performance aggregate to drive overall long-term change trajectories of the FTE. Ultimately, this will allow us to determine the suitability of remotely sensed micro-structural information as a proxy for assessing the vulnerability and resilience of the FTE to environmental change while understanding the mechanisms that underlie such a remote sensing approach. The outcome of this study will advance our ability to remotely sense FTE structure and function, which in turn will be of key importance for accurately predicting impacts of environmental change on ecosystem services within the ABoVE study domain and beyond.

Publications:

Eitel, J. U. H., Griffin, K. L., Boelman, N. T., Maguire, A. J., Meddens, A. J. H., Jensen, J., Vierling, L. A., Schmiege, S. C., Jennewein, J. S. 2020. Remote sensing tracks daily radial wood growth of evergreen needleleaf trees. Global Change Biology. 26(7), 4068-4078. DOI: 10.1111/gcb.15112

Eitel, J. U., Hofle, B., Vierling, L. A., Abellan, A., Asner, G. P., Deems, J. S., Glennie, C. L., Joerg, P. C., LeWinter, A. L., Magney, T. S., Mandlburger, G., Morton, D. C., Muller, J., Vierling, K. T. 2016. Beyond 3-D: The new spectrum of lidar applications for earth and ecological sciences. Remote Sensing of Environment. 186, 372-392. DOI: 10.1016/j.rse.2016.08.018

Eitel, J. U., Maguire, A. J., Boelman, N., Vierling, L. A., Griffin, K. L., Jensen, J., Magney, T. S., Mahoney, P. J., Meddens, A. J., Silva, C., Sonnentag, O. 2019. Proximal remote sensing of tree physiology at northern treeline: Do late-season changes in the photochemical reflectance index (PRI) respond to climate or photoperiod? Remote Sensing of Environment. 221, 340-350. DOI: 10.1016/j.rse.2018.11.022

Griffin, K. L., Schmiege, S. C., Bruner, S. G., Boelman, N. T., Vierling, L. A., Eitel, J. U. H. 2021. High Leaf Respiration Rates May Limit the Success of White Spruce Saplings Growing in the Kampfzone at the Arctic Treeline. Frontiers in Plant Science. 12. DOI: 10.3389/fpls.2021.746464

Maguire, A. J., Eitel, J. U. H., Griffin, K. L., Magney, T. S., Long, R. A., Vierling, L. A., Schmiege, S. C., Jennewein, J. S., Weygint, W. A., Boelman, N. T., Bruner, S. G. 2020. On the Functional Relationship Between Fluorescence and Photochemical Yields in Complex Evergreen Needleleaf Canopies. Geophysical Research Letters. 47(9). DOI: 10.1029/2020GL087858

Maguire, A. J., Eitel, J. U. H., Magney, T. S., Frankenberg, C., Kohler, 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. DOI: 10.1088/1748-9326/ac188a

Maguire, A. J., Eitel, J. U., Vierling, L. A., Johnson, D. M., Griffin, K. L., Boelman, N. T., Jensen, J. E., Greaves, H. E., Meddens, A. J. 2019. Terrestrial lidar scanning reveals fine-scale linkages between microstructure and photosynthetic functioning of small-stature spruce trees at the forest-tundra ecotone. Agricultural and Forest Meteorology. 269-270, 157-168. DOI: 10.1016/j.agrformet.2019.02.019

Meddens, A. J., Vierling, L. A., Eitel, J. U., Jennewein, J. S., White, J. C., Wulder, M. A. 2018. Developing 5 m resolution canopy height and digital terrain models from WorldView and ArcticDEM data. Remote Sensing of Environment. 218, 174-188. DOI: 10.1016/j.rse.2018.09.010

More details may be found in the following project profile(s):

• NASA Terrestrial Ecology (TE) Project Profile
• North American Carbon Program (NACP) Project Profile
• NASA Arctic-Boreal Vulnerability Experiment (ABoVE) Project Profile