1：Experimental Design and Method Selection:

The study involved multiscale experiments using ground-based and airborne measurements to assess SIF, reflectance, and gas exchange in boreal forests and agricultural crops. Methods included portable spectrometers, fluorometers, gas exchange systems, and imaging instruments to capture seasonal and stress-induced variations.

2：Sample Selection and Data Sources:

Samples included boreal tree species (evergreen: Pinus banksiana, Picea mariana, Picea glauca; deciduous: Populus tremuloides, Populus balsamifera, Larix laricina) in Alberta, Canada, and maize crops (Zea mays) in Nebraska, USA. Data were collected over growing seasons, focusing on winter-spring transitions and drought periods.

3：List of Experimental Equipment and Materials:

Instruments used included UniSpec and UniSpec DC spectrometers, MiniPAM fluorometer, LI-COR 6400 gas exchange system, Kestrel imaging spectrometer, IBIS imaging fluorometer, D-Flox and FluoSpec2 for ground-based measurements, and eddy covariance systems for GPP.

4：Experimental Procedures and Operational Workflow:

For boreal studies, measurements were made on potted seedlings over two years, with reflectance, fluorescence, and gas exchange data collected. For crop studies, irrigated and rainfed maize fields were monitored with airborne and ground-based instruments every 2 weeks, including SIF, reflectance, and eddy covariance measurements.

5：Data Analysis Methods:

Data analysis involved correlating Fs with CCI and photosynthesis, comparing SIF and GPP patterns, and assessing spatial and temporal variations using statistical techniques and software tools (not specified in detail).