Introduction
- The decaying process is the final step in the lifecycle of leaves. The step that leads to leaf decay is the process of the leaf falling off the tree. Chlorophyll is food for leaves, and once the tree stops producing chlorophyll the leaf falls off the tree. Chlorophyll is what keeps leaves green and healthy. When leaves start to loose chlorophyll they change color and start to become brittle and decay. The green chlorophyll that is produced in the summer overpowers the other chlorophyll that the leaf produces, therefore as the green chlorophyll breaks down the other chlorophyll is made visible because it is a different color. Eventually the leaf will turn brown because of the loss of all the chlorophyll. Right before leaf fall the protective layor of the leaf is waterproofed and strengthened, and the separation layer swells and becomes gelatinous. Due to this information our group should see a loss of chlorophyll in the leaves through the process of leaf decay. Since the protective layor is waterproofed we have concluded in our hypothesis that the leaves in water will decay the slowest, and the leaves in nothing will decay the quickest. We believe this because we think due to the leaves waterproofing layer the water will not effect it that quickly, and when the leaves are in dirt or on dirt the dirt will act as a protectant. We believe the leaves in nothing will decay the quickest because there is nothing to preserve them, therefore the elements will affect them more quickly.
Materials and Methods
-Red maple leaves
-dirt
-water
-containers
-wire mesh
-sunlight (greenhouse)
-scale
-camera
- First, our group gathered 160 red maple leaves and a bucket of dirt. We then weighed and labeled each leaf individually. Next, we set up 16 containers in the green house. Four containers contained nothing, four contained water, and eight contained dirt. We placed ten leaves in each container. So in total there were forty leaves in four empty containers, forty leaves in four containers filled with only water, forty leaves on dirt in four containers, and forty leaves in dirt in four containers. Next, we placed wire mesh over the containers with plain leaves, and the leaves on the dirt in order to keep them from blowing away. For our experiment we will check each week and see the stages of the leaves over four weeks. We will also take pictures each week in order to have good observation records. Each week we will take away one container in each group to account for the stages of leaf decay. In order to have good data we will reweigh each leaf to see the weight loss.
Analysis
- We will analyze the weight loss and the color change from the first week through the fourth week. Because we weighed the leaves before, we will be able to tell how much the leaves have deteriorated from week to week when we weigh them again. From week to week we will be able to tell color change because we will compare the pictures we take of the leaves. We will also see the different rates of deterioration among the groups: water, on dirt, in dirt, and plain.
Bibliography
-Bell, Ritchie C. and Lindsey, Anne H.. Fall Color and Woodland Harvests. Laurel Hill Press, Chapel Hill, N.C. 1990. Pg. 3-4, 94.
-Encyclopedia Americana 1995 ed. Vol. 17. "Leaf." Pg.108-109.
-Ketchum, Richard M.. The Secret Life of the Forest. American Heritage Press, New York 1970.
-Platt, Rutherford. 1001 Questions Answered About Trees. Dodd, Mead and Company, New York 1959. Pg. 8,86.
-World Book Encyclopedia 1997 ed. Vol. 12 "Leaf." Pg. 152,153.
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