how does the number of stomata in a leaf relate to the rate of transpiration
How to Calculate Leaf Surface Area. The rate of transpiration is measured as the amount of water lost/ square meter/ minute. Because water evaporates through the many stomata on the leaf surface, the rate of transpiration is directly related to the surface area. To arrive at the rate of transpiration, therefore, you must calculate the leaf surface area of each plant: Because most stomata are found in the lower epidermis, you will determine that surface area. 1  Lay the leaves to be measured on a 1-cm grid and trace their outlines. 2  Count the number of square centimeters.