MODELING DYNAMIC BEHAVIOR OF LEAF TEMPERATURE AT THREE-DIMENSIONAL POSITIONS TO STEP VARIATIONS IN AIR TEMPERATURE AND LIGHT

Abstract

Organisms such as plants grow as a result of the influence of their genetics and microenvironment,consisting of physical, chemical, and biological factors. The microenvironment or microclimate is the environmentclosely surrounding these organisms and varies in time and space. To control processes more optimally, it is necessaryto understand how living organisms respond dynamically to their physical microenvironment. Most models beingdeveloped to explain this relationship through steady-state models are descriptive (deterministic) and too complex to beused for control purposes. Therefore, it is attempted in this work to develop a dynamic black box model. For this studyonly air temperature was considered in 3-D (three dimensions). The objective of this research was to model the dynamicresponse of leaf temperature to time variations in air temperature closely surrounding that leaf, and to light-darkalterations. This biosystem is modeled using an ARX model structure (black box). Three-dimensional gradients in airtemperature around the plant were shown and analyzed. It is demonstrated that a complex process such as the responseof leaf temperature to changes in 3-D ambient air temperature and light-dark alterations can be modeled with a mean r 2between 92.7% and 99.9%.