Abstract. Surface downward shortwave radiation (DSR) and photosynthetically active (PAR) play critical roles in the Earth's surface processes. As main inputs of various ecological, hydrological, carbon, solar photovoltaic models, increasing requirements for high-spatiotemporal-resolution DSR PAR estimation with high accuracy have been observed recent years. However, few existing products satisf...

Background Under field conditions, the development of crops depends on capacity of the canopy to intercept incident radiation and convert it into new biomass (Gifford et al. 1984). The amount of incident radiation intercepted depends on the leaf area index (LAI) and canopy orientation in space. The fraction of the incident photosynthetically active radiation (IPAR) that is absorbed by a canopy ...

Ultraviolet-B radiation is an important component of the environment, acting as an ecophysiological factor with the potential to alter plant growth and photosynthesis. Plant response to UV-B is effectively regulated by photo protective mechanisms that dissipate excess radiation. At the morphological & physiological level these photo repair mechanisms and antioxidant responses mop up reactive ox...

In open places, plants are exposed to higher fluence rates of photosynthetically active radiation and to higher red to far-red ratios than under the shade of neighbor plants. High fluence rates are known to increase stomata density. Here we show that high, compared to low, red to far-red ratios also increase stomata density in Arabidopsis (Arabidopsis thaliana). High red to far-red ratios incre...

A simple model that describes growth in terms of physical and physiological processes is needed to predict growth rates and hence the productivity of trees at particular sites. The linear relationship expected between absorbed photosynthetically active radiation (phi(pa), MJ m(-2)) and dry mass production (G(t)); i.e., G(t) = epsilonphi(pa), where epsilon is the radiation utilization coefficien...

Vegetation productivity metrics such as gross primary production (GPP) at the canopy scale are greatly affected by the efficiency of using absorbed radiation for photosynthesis, or light use efficiency (LUE). Thus, close investigation of the relationships between canopy GPP and photosynthetically active radiation absorbed by vegetation is the basis for quantification of LUE. We used multiyear o...