Evaluation of a radiosity based light model for greenhouse cucumber canopies
Evaluation of a radiosity based light model for greenhouse cucumber canopies
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DOI：
10.1016/j.agrformet.2011.02.016
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发表时间：
2011-07
影响因子：
6.2
通讯作者：
Dirk Wiechers;K. Kahlen;H. Stützel
中科院分区：
文献类型：
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作者：
Dirk Wiechers;K. Kahlen;H. Stützel
光照分布是植物发育和生长过程的关键因素，光照分布在很大程度上取决于叶片分布，而叶片分布受冠层植物排列等因素的影响。在器官水平上对光分布的精确模拟是植物动力学模型的重要组成部分，该模型结合了植物对环境的结构和生理适应。静态三维植物模型与三维光模型相结合用于分析叶片水平的复杂光分布，但几乎没有详细的测量来评估模拟结果。本研究利用黄瓜（Cucumis sativusL.）冠层中单个叶片的光测量对一个模型进行了高水平的详细评价。我们将一个静态的3D植物模型与周围树冠的模型和一个基于三维辐射的光分布模型结合起来，该模型来源于单个器官尺度的数字化植物。分析了植物密度和间距的变化，以覆盖一系列冠层结构。通过应用遮阳封装来排除光环境的组成部分，然后连续揭开，可以在越来越复杂的水平下调查场景。结合3D植物光分布方法可以确定光方向和树冠结构的相互作用，以及模拟精度的差异。根据树冠结构和遮阳处理的不同，光分布的范围从封闭处理的指数形垂直梯度到非封闭条件下的接近平坦的光剖面。综上所述，基于详细的三维表面植物和光分布模型的叶片水平PAR模拟适合于在器官水平上推导光诱导生理反应。
Light distribution is a key factor of developmental and growth processes, and strongly depends on the foliage distribution which is affected, e.g., by the arrangement of the plants in the canopy. The precise simulation of the light distribution on organ level is an essential component for dynamical plant models which incorporate structural and physiological adaptions of plants to their environment. Combinations of static 3D plant models with 3D light models are used for analyzing the complex light distribution on leaf level in silico, but detailed measurements for evaluation of simulation results are almost non-existent. This study addressed the evaluation of a model on a high level of detail using individual leaf based light measurements in canopies of cucumber (Cucumis sativusL.). We combined a static 3D plant model derived from digitized plants on an individual organ scale with a mock-up of the surrounding canopy and a 3D radiosity based light distribution model. Variations of plant density and spacing were analyzed to cover a range of canopy architectures. An exclusion of components of the light environment by applying a shading encasement followed by a successive uncovering allowed investigating the scene under increasing levels of complexity. The combined 3D plant-light distribution approach allowed determining the interaction of the light directions and the canopy architecture as well as differences in the accuracy of the simulations. Depending on canopy architecture and shading treatment, the light distributions covered a range from exponentially shaped vertical gradients in encased treatments to nearly flat light profiles in nonencased conditions. In conclusion, simulations of leaf level PAR based on combinations of detailed 3D surfaced-based plant and light distribution models are suitable to derive light-induced physiological responses on organ level.