6th Graders Design Experiments on Plant Transpiration
by Pam Collinge
October 28, 2009
Do plants transpire water and waste when they are dormant?
Will a conifer transpire waste through the needles?
Students are developing experiments that answer these questions by using plants in the outdoor classroom. Plastic sacks filled with a small piece of gravel are tied around the leaves of the plants with a twist tie.
Students are collecting the water that transpires through the leaves and measuring to the nearest tenth of a cc by using a small syringe. Data is being collected and results will be analyzed the first week of November.
Results indicated that conifers do indeed transfer water through the needles. An average of .92cc of water were collected from the conifer bags. The perennial plants that were going dormant seemed to transpire water as well, but at a much slower rate. We did end up with a few outliers in our data set. Students inferred that the plants that showed a much greater rate of transpiration were probably annual plants that were starting to die.
