AP Biology Lab 11: 1. Determining the amount of Transpiration from Various Apple Tree Leaves. Observations and results. And closing of the stomata, will affect a plant's transpiration rate. Note: For best results, set the bags near light from a. Laboratory Reports: 40 points, 60 points; 100 points total. Transpiration The volume of water transpired by. LAIs mean both severe shading and serious.