A new report explains why many Americans can't afford the average new car. Mar 16, 2014 at 3:30PM. Ford's F-150 is America's best-selling new vehicle. But at an average transaction price of close to $40,000, it's out of reach of many American households -- or should be, says a new report.
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.
This is an adaptation to check excessive transpiration in these plants. Number of Stomata (Stomatal Frequency): The number of stomata in a definite area of leaf varies from plant to plant. Xerophytes possess larger number of stomata than mesophytes. Number of stomata/sq cm. is 1000 â 60,000 in different plant species. The number of stomta per unit area of leaf is called Stomatal Frequency. Stomata frequency of trees and shrubs is higher than herbs. Stomata nearly occupy one to two percent of total leaf area when fully open.