Heat Transfer Analysis of Factors Affecting Plant Leaf Temperature. Significance of Leaf Hair

Abstract

The purpose of this paper is to gather together all variables important in heat balance in plant leaves into one analysis. In this way, an overall under- standing of the heat balance can be determined and the relative importance of each of the variables can be known. The heat transfer analysis will be made on plant leaves exposed to the sun during midday hours. Formulas will be derived which relate steady state leaf temperature with various significant parameters such as wind velocity, water evaporation rate, leaf size, and amount of surface hair. A new role will be shown for leaf hairs. They are shown to be im- portant in the heat balance, particularly in cactus where they are found in great quantity.