Ty (U24-002-C Conductivity Logger, Onset, Bourne, MA, USA) have been deployed above the sediment surface close to the flux tower. two.3. Flux Data and LUE Calculation Four-year continuous 10-Hz time series raw information have been measured applying an EC method and recorded in a CR3000 datalogger (Campbell Scientific, Inc., Logan, UT, USA). The EC program incorporated a three-axis sonic anemometer (CSAT-3, Campbell Scientific, Inc., Logan, UT, USA) and an open path infrared gas analyzer (LI-7500, Li-COR Inc., Lincoln, NE, USA). Net ecosystem exchange (NEE) was calculated by means of flux corrections and good quality control procedures [44] (including axis rotation, ultrasonic correction, frequency response correction, steady-state test, turbulent situations test, statistical test, absolute limits test, and rain test) primarily making use of the EddyPro6.1 software program (Li-COR Inc., Lincoln, NE, USA). Marimastat custom synthesis daytime Re (ecosystem respiration) was estimated from daytime temperature according to the fitted nighttime temperature-respiration exponential regression model [44] after which GPP was calculated as the value of daytime Re minus NEE (Equation (1)). LUE was computed as the ratio of GPP and APAR (Equation (two)), where APAR was the product of PAR and f APAR (fraction of absorbed PAR) (Equation (3)). f APAR was derived from SWin (incoming shortwave radiation) and SWout (outgoing shortwave radiation) (Equation (4)). The calculation of LUE was depending on half-hour data of GPP and APAR then converted to every day imply values. Within this study, the downward (in the atmosphere to mangroves) and upward carbon fluxes had been represented by constructive and damaging values, respectively. GPP = Re – NEE LUE = GPP/APAR APAR = PAR f APAR f APAR = 1 – SWout /SWin 2.four. Spectral Measurement and Processing With spectral reflectance sensors (SRS; Decagon Devices, Pullman, WA, USA) mounted in the height of 9 m above the canopy, canopy spectral radiance and sky irradiance had been constantly measured to calculate PRI. A pair of SRS sensors were fixed at the identical height together with the upward-facing sensor measuring sky irradiance and also the downward-facing sensor measuring canopy spectral radiance. The downward-facing sensor was affixed facing north having a 45 view zenith angle. The field of view of the upward sensor was hemispherical as well as the downward one was 36 with an optical footprint of 200 m2 . Spectral measurements under rainy situations had been excluded. Time series of canopy reflectance values at 531 nm (r531 ) and 570 nm (r570 ) bands had been derived from corresponding canopy radiance and sky irradiance measurements, and PRI was calculated according to these two canopy reflectance values [26]: PRI = (r531 – r570 )/(r531 + r570 ) (five) (1) (two) (3) (four)Remote Sens. 2021, 13,5 ofTo distinguish the relative contribution of two components (constitutive and facultative) to the temporal variation from the PRI time series, we calculated numerous PRI-derived indicators for each and every day to explore the underlying physiological mechanisms. PRI0 was calculated as the mean value of PRI under somewhat low light conditions (solar elevation angles among 355 ) to represent a dark-state pigment content material (constitutive) with 5-Azacytidine Biological Activity minimal xanthophyll de-epoxidation. The application of this criterion of solar elevation angles excluded data of poor quality below also low light situations [37]. Sunlit PRI was calculated because the minimum PRI about noon (among 11:30 and 13:30 nearby time) with all the strongest illumination. Sunlit PRI was subtracted from PRI0 to calculate seasonal PRI,.