Tuesday, May 8, 2018

Forestry for Fifth Graders (07 & 08 May 2018)

If you have visited the Chippewa Watershed Conservancy's Audubon Woods Preserve in the past week you may have noticed some metal T-posts that weren't there before.

A metal T-post standing alone at Audubon Woods Preserve

Why are these posts at Audubon Woods?  What are they for?

For the past seven years, I have used Audubon Woods as an outdoor science classroom for local elementary students.  The T-posts are meant to be semi-permanent education stations.  In the past, every time I took students to Audubon Woods I would set up temporary stations at somewhat random points in the woods.  There is a lot that can be done by using temporary points, but more can be learned long term if students use the same locations time after time.

With permission, I set about placing posts along a series of transects (lines) throughout the woods.  I set up three transects at regularly spaced intervals in the woods and placed six evenly-spaced posts along each transect.  Now with semi-permanent locations, data that the students collect can be compared over time.

So what kinds of data are the students collecting?

Over the past two day (07 & 08 MAY 2018) I have been working with fifth grade students from Shepherd Elementary.  These classes were able to travel to Audubon Woods because last fall their teachers applied for and received a Wheels To Woods field trip grant

Students are measuring the circumference of trees in their study plot and using that to calculate diameter.

Measuring a tree's circumference

Measuring large trees takes teamwork

Students are also counting trees at their study plot to determine the number of trees in one acre of forest and in the entire forest.  Audubon Woods is 40 acres in size - at 43,560 sq. ft/acre, that means Audubon Woods is 1,742,400 sq. ft!  Counting all of the trees in an area this size would be an impossible task.  Luckily, it is easy to count the number of trees in a much smaller area and then use that number to estimate the total number of trees in the forest.  A circle with a radius of approximately 37 feet will have an area of 1/10 acre.   Remember those T-posts?  Students counted every tree within 37 feet of the post and used multiplied that number by 10 to find the number of trees in one acre and then again by 40 to find the total number of trees in Audubon Woods.

Tape measures are an important forestry tool

Measuring trees to make sure they fit in their plot

Students then calculated the number of leaves on the forest floor by counting the number of leaves in one square foot and then multiplying by 43,560 to get the number of leaves in one acre, and then by 40 to get the total number of leaves on the floor of Audubon Woods.  Imagine if a single square foot holds exactly 100 leaves, this would calculate out to over 172 million leaves in the forest!

Students had a square made from PVC pipe to make their task easier

Counting leaves from a single square foot of forest


Students also calculated the weight of all the leaves in the forest, identified and sketched leaves, and drew a sketch of the forest near their study plot.  Perhaps just as important as the science, this field trip allowed students to get out of the classroom for a few hours.  The months of April and May are testing time in Michigan.  Students spend hours taking state-mandated assessments and even more hours taking tests required by their local school district.  A field trip like this exposes them to sights, sounds, and smells that thy can never experience in the classroom.

Large-flowered Trillium

Trillium surrounded by Mayapple

Spring Beauty flowers


Skunk Cabbage

Wood Frogs were everywhere hidden among the leaves

Another Bloodroot flower

The maples and other trees are just starting to leaf out

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