VARIABILITY IN THE FRACTION OF INTERCEPTED PHOTOSYNTHETICALLY ACTIVE RADIATION: EFFECTS OF .........

One of the key drivers of biomass production is light interception by plant canopies. Quantifying the percentage of intercepted photosynthetically active radiation (FIPAR) spatiotemporal patterns is critical for quantifying CO2 assimilation at the landscape level, ecological process modelling, and remote sensing data interpretation. One significant problem to consider when characterising FIPAR is temporal scale, as FIPAR is temporally dynamic and changes constantly under varied irradiance conditions. This study examines the impact of irradiance conditions and temporal scales on FIPAR variability using ground measurements taken across a variety of landscape ecosystems. This study looks at 1) FIPAR variability as a function of solar zenith angle (SZA), weather conditions, and seasonality using hourly, daily, 10-, and 30-day integrated data, and 2) the impact of irradiance conditions on FIPAR as a function of SZA, weather conditions, and seasonality. The goal is to figure out the best time and temporally integrated processes for generating FIPAR for better landscape characterization. For around 78 ecological sampling units (ESU) around the world, both instantaneous and integrated FIPAR values were obtained and compared for various irradiance circumstances and temporal periods. When comparing instantaneous and integrated FIPAR values, the data imply that diurnal time and solar zenith angle (SZA) of illumination are more important than meteorological condition and integration time. When gathered in the morning or afternoon as a function of SZA, the instantaneous in-situ measurements serve as a good estimator of the integrated values. When instantaneous measurements are acquired at around 9:30 or 14:30, both non-linearity and substantial variability in the connection between instantaneous and integrated FIPAR are seen.

Please see the link :- https://www.ikprress.org/index.php/JOGEE/article/view/187