This paper analysed the absorption and the attenuation of photosynthetically active photon (PPFD) in different plant population in three agroforestry systems. Furthermore, the distributions of light intensity in spatial and temporal dimension were also analysed. The results were as follows: The model of Ginkgo biloba leaf and fruit utilization-leguminous crop can capture 92% of the incident PPFD, with high efficiency of light utilization, and the attenuation of PPFD through the canopy was appoximated by Beer's law. The relationships between photon absorption, leaf area and aboveground biomass were fitted the equation Y=axb. Meanwhile, the wood and fruit utilization Ginkgo biloba trees can be allocated in the toppest strata for their high light transmissivity and variation coefficient of light intensity, but their canopy structures needed to be regulated. The changes in light intensity with time were affected by the condition of canopy structure and solar movement.
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