###### Abstract  
Solar-induced chlorophyll fluorescence (SIF) is closely related to the light-reaction process and has been recognized as a good indicator for tracking gross primary productivity (GPP). Nevertheless, it has not been widely examined how SIF and GPP respond to temperature. Here, we explored the linkage mechanisms between SIF and GPP in winter wheat based on continuous measurements of canopy SIF (\(cSIF\)), GPP, and meteorological data. To separately explore the structural and physiological mechanisms underlying the SIF-GPP relationship, we studied the temperature responses of the estimated light use efficiency (\(LUE_{p}\)), canopy-level chlorophyll fluorescence yield (\(cSIF_{yield}\)) and photosystem-level chlorophyll fluorescence yield (\(\Phi_{F}\)) estimated using canopy-scale remote sensing measurements. We found GPP, red canopy SIF (\(cSIF_{688}\)) and far-red canopy SIF (\(cSIF_{760}\)) all exhibited a decreasing trend during overwentiering periods. However, GPP and \(cSIF_{688}\) showed relatively more obvious changes in response to air temperature (\(T_{a}\)) than \(cSIF_{760}\) did. In addition, the \(LUE_{p}\) responded sensitively to \(T_{a}\) (the correlation coefficient, r = 0.83, \(p\)-value \(<\) 0.01). The \(cSIF_{yield,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \,\emitted SIF [5]. The energy distribution and transfer of the absorbed energy are crucial for linking SIF to GPP, whereas the energy distribution among PQ, SIF, and NPQ is largely influenced by environmental conditions. Temperature affects the photosynthetic capacity of plants through several complex biochemical processes [6]. Many overwintering species at higher latitudes experience a decline in photosynthetic rate due to chilling, especially for evergreen needle forests (ENF; [7; 8]). The winter cold imposes thermodynamic constraints, slowing the enzymes related to the activities of PQ and the Calvin cycle; therefore, light-harvesting complexes (LHCs) cannot completely utilize the absorbed light for CO\({}_{2}\) fixation. Because photoinhibition susceptibility is stronger at low temperatures, a more severe decline in photosynthetic activity occurs when chilling is produced under high light [9; 10]. NPQ is an important photoprotective mechanism that plays a role in protecting the photosystem II (PSII) from damage from cold temperatures [8; 11]. The quantity of PsbS protein and carotenoids (particularly xanthophyll pigment and corresponding xanthophyll lutein cycle pigment) determines NPQ capacity [12; 13; 14]. At the leaf scale, [PERSON] et al. [6] reported that seasonal variation in fluorescence quantum yield was in agreement with the changes in the quantum yield of photochemistry (\(\Phi_{PSII}\)) for ENF throughout winter. At the canopy scale, [PERSON] et al. [8] and [PERSON] et al. [15] explored the temperature response of SIF and GPP in ENF. They found that SIF and GPP exhibited a decreasing trend during overwintering periods and demonstrated that NPQ played a key role in protecting plants from damage in winter. Overall, low temperatures affect the energy distribution, which further impacts the changes in SIF and GPP. It is worth emphasizing that the GPP estimation based on canopy SIF is challenged by the mixed effects of structure and physiology. Due to scattering and reabsorption within leaves and canopies, the observed canopy SIF is not the true SIF emitted at the photosystem level (Figure 1). Therefore, the apparent fluorescence yield at the canopy level (\(cSIF_{yield}\)) may not be the real yield (the total fluorescence yield at the photosystem level, \(\Phi_{F}\)). If the reabsorption process and scattering process are not appropriately addressed, erroneous physiological estimates may be deduced.