海岸带复合农林业系统植物种群光环境特征研究

本文对三种银杏-农作物复合模式下植物种群对光合有效辐射的削弱和截获进行了模型化分析,并探讨了不同模式下光照强度的时空分布规律。结果表明:银杏果用-叶用-豆类作物复合模式具有最好的复合光效益,光能截获率可达92%;PAR在植冠层的削弱遵循Beer-Lambert定律;植物种群的叶面积、地上部分生物量、光吸收的关系可以用Y=ax^b数学模型描述。同时,果用、材用银杏冠层有较大的透光性和光强变异系数,可以作为银杏-农作物初期经营的上层树种,但要注意冠形的调控;光强的时间变化受冠层条件和太阳高度角的双重影响。

The characteristics in light climate of plant populations in coastal agroforestry in China

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=a xb . 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.