Saturday, October 22, 2016

Oak Trees and Acorns as Teaching Tools

By Mary Van Dyke

Here in the DC metro area on the East Coast of the US it is often the Year of the Acorn!

On my walks around the neighborhood, I find that we have many shapes and sizes of acorns - and a large diversity of oak species (genus Quercus).
Overcup Acorns
Did you have lots of oak trees and acorns too?

So what to do with this "oak mast" and wonderful bounty of a teaching tool?

White Oak Acorn Caps

Sawtooth Oak Acorns

Red Oak Acorn Caps

A huge Bur Oak Acorn!

The Great Red Oak, Boxerwood Gardens
Lexington VA

Here’s The Great Red Oak Tree at Boxerwood Garden at Lexington VA. The huge oak tree forms the focal gathering point of their garden and teaching for pre-K and up. Education Director, Jess Sullivan and her colleagues at Boxerwood use the Great Red Oak Tree and a squirrel puppet, Chatter, for several teaching programs.

Folkmanis Gray Squirrel Puppet from
Chatter's Acorn Lesson from Boxerwood

Willow Oak
Jamestown Elementary School

The Willow Oak, is the centerpiece of the courtyard at Jamestown Elementary School, and the focal heart of the school. Many students spent time learning in the canopy of the beautiful Willow Oak, enjoying the shade in the heat of the summer and the structure in the winter.

At elementary schools I enjoy teaching Goods from the Woods for 4th grade standards on Natural Resources, and Health Assessment of a Tree lesson I developed for 5th Grade standards.
I teach about Ecosystem Services of Trees using i-Tree Design or i-Tree Canopy (suitable for 4th - 8th Grade outdoor learning) with focus on the Oak, Maples, Pines and other trees in the schoolyard.

For any tree, with a simple tape measure and using a laptop or tablet with i-Tree Design, it is easy to calculate the dollar value of some major ecosystem contributions of the tree: stormwater/runoff mitigation, contribution to air quality, CO2 uptake of any tree, and the energy impact on nearby buildings. That's cool to know, and fun to compare different trees. It is good to appreciate the living value of trees and their contribution in ecosystem services, in addition to their timber value, aesthetic value or commercial value for products.

Insect-Oak Relationships
Oak leaves often have an array of insect eggs, scale and galls on them.  Pick a few leaves and see what you can find.
Galls are under-researched and an interesting insect/plant symbiosis. This year we found several scale insects on a young Willow Oak and fun pink woolly gall that looked like a bit of pipecleaner.

Dr.Doug Tallamy (Professor in Entomology and Wildlife Ecology at University of Delaware and author of bestseller Bringing Nature Home) tells us that a single oak tree can support 534 kinds of lepidoptera (moths and butterflies). You usually will be lucky too finding evidence of insects living on your native oak trees!

Raking Leaves
I compost the oak leaves we rake up in the school courtyard and teach 1st, 2nd and 3rd grade students about decomposers.

First graders rake up oak leaves as a service learning project to clear their garden bed - and make a huge leaf pile for the Pre-K classes to have fun jumping into!

Collecting Acorns and Acorn Viability Testing
Will your acorn grow into a mighty oak tree? Has your acorn been chewed by a mouse, or drilled into by a weevil? Testing acorns for viability is a fun experiment for elementary and middle school students. Gather lots of acorns. Set up an aquarium full of water, tip in the acorns. Do they sink or float?
  • The acorns that sink are likely to be viable (as they have seed still inside). 
  • The acorns that float, will have been eaten by an animal or our otherwise decayed. 
  • Count how many acorns floated? How many sank? 
  • How many acorns are viable? What percentage of the whole collection of acorns are viable seeds?  
  • Are any of your acorns already sprouting? Can you see a root and shoot?

Acorn as Seeds and Sprouting
Study sprouting acorns as part of your plant classification studies and introduction to dicots/monocots. By destructive testing you can split apart an acorn and find: the seed coat, root, shoot and the two food parts (cotyledons). Oaks are classified as large flowering plants, and are dicots.

Acorn Planting
Plant an acorn. Choose a viable acorn and plant it in a gallon pot, keep outdoors and moist over the winter. Keep animals away from digging in your pot and eating the acorn! Do you see the oak seedling sprout? Find a good place to plant your small oak tree in the spring.

Identify Your Acorn Caps
Look at photos of 12 different kinds of common acorn caps in the East Coast: on this LINK sourced from the USDA-NRCS plants database

Noticing Patterns
As I am teaching I highlight differences in patterns between the two major families of red oaks and white oaks. Red oaks have pointed leaves usually and white oaks are rounded. Note: acorn caps have spirals similar to pinecones, pineapples and sunflowers: the familiar Fibonacci-like spirals are a familiar pattern of how plants grow.

Resources for teaching about oaks

Next blog
There are plenty of potential for crafts beyond teaching the oak and acorn lifecycle and acorn biology. Next blog we’ll look at some crafts that use oak tree leaves and acorn caps.

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