OOS 33-4 - Linking leaf to globe with thermal remote sensing

Background: Ecosystem function is governed by interactions between carbon, water, and energy fluxes at different scales, from individual leaves to entire ecosystems. Eddy covariance towers provide measurements of these fluxes, but their site-specific nature and limited temporal and spatial resolution pose challenges for scaling up to larger areas. Remote sensing, including thermal infrared (TIR) remote sensing, can complement eddy covariance measurements by providing contextual information on vegetation function and spatially explicit measurements of ecosystem properties. However, the potential of TIR remote sensing in linking thermal and energy fluxes at tower scales has not yet been fully explored.

Results/

Conclusions: In this study, we used Uncrewed Aerial Vehicle (UAV) flights to obtain high-resolution TIR imagery and field measurements of tree water status in an Eastern deciduous forest. We show that TIR remote sensing can resolve temperatures of individual tree crowns, which are linked to biophysical processes including transpiration and plant water status. By integrating TIR remote sensing with energy flux measurements, we gained insight into the impact of changing surface temperatures on carbon and water fluxes at multiple scales. Our findings highlight the potential of TIR remote sensing for monitoring vegetation water status and detecting early warning signs of vegetation stress, as well as its ability to provide a more comprehensive and integrated view of ecosystem functioning.

Overall, our research showcases the potential of TIR remote sensing in linking thermal and energy fluxes for comprehensive ecosystem understanding, particularly at the intermediate scale. Our findings emphasize the unique information provided by TIR remote sensing and can help guide the development of more integrated approaches to ecosystem monitoring that combine TIR remote sensing with energy flux measurements from eddy covariance towers. This integrated approach can lead to a more complete and holistic view of ecosystem functioning from leaf to globe.