Fall, leaves, fall; die, flowers, away;
Lengthen night and shorten day;
Every leaf speaks bliss to me,
Fluttering form the autumn tree.
-Emily Bronte
Final Draft of Proposal
Introduction:
As the days get shorter and the nights get cooler the trees begin to shed their leaves in preparation for winter. During the winter there is not enough sun or water for the photosynthesis process. Consequently, the trees cease activities, takes a rest, and lives off the nutrients it stored during the other seasons. In this shut-down process, leaves fall when the veins close off and a layer of cells called the abscission, forms at the point of attachment to the branches. This abscission, or separation layer closes off the flow of water from the tree to the leaf. Without the intensity of the sun and the chlorophyll in the leaf to keep it healthy, the green color fades away. As a result, the other colors become more prominent and the leaves fall.
Obviously all leaves do not fall at the same time, therefore each type of tree must go through the shut-down process at it’s own speed. Therefore, in this lab, our goal is to explore the realm of timing and patterns of timing of leaf fall. We propose to prove that there are specific patterns of timing in leaf fall based on location, weather conditions, species, and size.
Question:
Can specific patterns be found in the process of leaf fall? Does location, weather conditions, species and size affect these specific patterns of timing?
Materials:
-80 feet of chicken wire
-red pipe cleaners to mark bins
-handmade stakes
-data sheets
-leaf identification guides
-ziploc bags to store leaf samples
Methods:
We plan on collecting data in the field every other day and will continue to do so until our maximum/minimum curve levels off (approximately mid-November). Then, we will assign each member to a certain location, filling out a leaf chart, and ultimately compiling our data to discover significant patterns of timing. In order to do this, we will focus on four categories which include:
1. Location
To collect leaf data we will randomly place a total of twenty sampling bins (approximately one foot in diameter) in five different areas (four bins per area) which include:
-Deep forest
-Edge of forest
-By the pond
-By the creek
-Around single trees
Predictions
-Leaves will fall faster towards the edge of the forest than in the deep forest because the trees around the edge of the forest will have more exposure to weather conditions.
-Leaves near the water will have a slower rate of fall. This is because the water will supply the leaves with more nutrients, therefore it will take the leaves longer to dry out.
-Individual trees will shed their leaves at a faster rate due to a greater exposure to the elements.
2. Weather Conditions
We plan to record the weather conditions daily because we believe that this may have an immense affect on the timing of leaf fall that day. For example, heavy winds could cause excessive leaf fall. Therefore, if we do not take this into account, our data will not be accurate. For example, we recognize that the following weather conditions will have an effect on our data:
-Wind
-Excessive Sun
-Heavy storms
Predictions
-Wind will increase the rate of leaf fall.
-A day with extreme sunlight as opposed to an overcast day will dry the leaves out and therefore cause them to fall at a faster speed.
-A day with a heavy storm as opposed to calm day will also cause leaves to fall faster.
3. Species
Through research we have found that timing is genetically related to each species. Thus, the species of a tree plays an important role in the patterns of timing for leaf fall. Through our data we will record the different species and number of each in order to determine the peak times of leaf fall in each species. In order to do this we will have to incorporate the help of a leaf manual.
Predictions
-Each species of study will have a unique peak time rather than all types peaking at the same time.
4. Size
We believe that patterns of timing will also be evident in the size of the leaves that fall. Therefore, when examining our bins we will record the different sizes of each leaf. Our method of defining size will be as follows:
-Small, less than 2 inches
-Medium, from 2-4 inches
-Large, greater than 4 inches
Predictions
-We think that the leaves, in general, will fall in this succession: small, medium, and large. Mainly, because the smaller leaves will drain their nutrients at a faster rate and consequently will fall faster and so on.
Analysis:
Through the integration of our data we will attempt to prove our hypothesis and predictions to be true. In researching these four areas, we hope unveil specific patterns of timing in the process of leaf fall. Our ultimate goal is to shed a new light on leaf fall in our eyes as well as researchers in the future.
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