| Explore | Having observed six trees of different species, sizes, and shapes, we recorded our findings and learned more about trees in general. For example, we found a 13-foot apple tree that has a reddish color near the base of the trunk, a thin-trunk malunggay tree that’s just starting to grow new leaves, an oddly-shaped plumeria tree without flowers, a very thin yucca tree in a pot that leans to the left, a 19-foot guava tree that’s 27 years old, and a healthy, leafy tree that we’re not entirely certain what species it is (maybe Laurus nobilis?). Using our findings, we calculated the benefits of our trees; based on the diameter of the trunks, we determined that the larger the tree, the more gallons of water are absorbed from storm runoff and the more beneficial the tree is to air quality. Some of our smaller, sadder trees don’t contribute too much to air quality or energy conservation. |
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| Research Question | How does the health of a tree affect how a cutting (leaves and a branch) dies? We came up with this question after reminiscing about our childhood experiences with snapping leaves and branches only to see them rot and die. This question fits what we know about trees because without a direct line to the tree and the nutrients it offers, leaves and branches will over time wither and fade. |
| Predictions | We predict that the leaves/branches from the healthiest tree will die the least or the slowest because they have enough nutrients and necessities stored to last a while; the leaves/branches from the least healthy tree will die the fastest and in the worst way because they don't have as much support left in them once cut off from the tree. However, another prediction we have is that no matter how healthy the trees are, all the leaves/branches will die equally because they're "on their own," so to speak. Our third (and maybe most unlikely) prediction is that the healthiest leaves/branches will die the fastest because they have a lot of water stored in them, which might cause the rot to occur more quickly. |
| Experimental Design | Our plan is to cut off a branch with some leaves on it from each of five trees and record how fast and in what way the leaves die once separated from the tree (see steps in Files for details). The variables we are testing are the health of the leaves (determined by color, size, shape, and texture) and the time it takes for the leaves to completely decay. Using our Health-O-Meter For Leaves (see in Files), we will determine the health of the leaves from each of the trees everyday to monitor how fast they decay. The variables we are keeping constant include the species of tree and the environment in which the cuttings are stored. We will record data by observing the changes in color, size, shape, and texture of the leaves each day and matching the descriptions with a grade on the Health-O-Meter. By the end of the experiment, we can determine which leaves decayed the fastest by noting which leaves made it to grade level 0 first, and the extent to which the leaves decayed by noting which leaves showed the biggest change in grade level. |
| Conclusion | From this experiment, we can conclude that cuttings from healthier trees will develop leaf rot and die slightly faster than those from less healthy trees. This is likely because healthier leaves contain more water, which can contribute to the growth of leaf rot (we researched that moisture is often the cause of rot). Our hypothesis was incorrect. We could expand the results of this experiment by repeating it or trying it with a different species of tree. |
| Investigation Theme | TREE |
| Grade Level | High School Students (Grades 9,10,11,12) |
| Teacher Name | Crystal Davis |
| School Name | California Academy of Mathematics and Science |
| Session | Spring 2021 |