Growing With Science Blog

I’m “sprucing” things up here at Growing with Science in preparation for hosting the Festival of the Trees Carnival at the end of the month. For the next few weekend science fun posts, we’ll be learning about trees and doing some fun tree science activities.

I. What is a tree?

Most of us recognize a big tree when we see one, but sometimes it may be hard to tell whether a plant is a large shrub or a small tree. What do you think? Brainstorm and write down all the words you use to describe a tree.

One definition might be “a tree is a perennial, woody plant that grows to at least 20 feet tall and has an erect (straight up) main stem.” Talk about what that means and if all the trees you know will fit this definition. Can you think of something more? Let us know what you decide.

II. Why study trees?

Trees are so important. Can you think of a list of benefits of trees? Here’s just a few we thought of:

• shade (really important in Arizona!)
• food and shelter for wildlife
• rubber
• paper and paper products
• source of wood products such as furniture, houses, pencils, musical instruments
• food for us
• fuel for heating
• medicines such as aspirin and quinine
• produce oxygen
• conserve water
• reduce pollution

Can you add to this list? Do some research to find more benefits of trees.

III. External parts of a Tree

Vocabulary:

• bark
• trunk
• crown
• leaf/needle
• branches
• roots
• twigs
• nuts
• fruit
• flowers
• buds

Make index cards with each of these names (make sure you have at least one card for each child participating.) Punch holes in the cards with a hole punch.  Cut pieces of yarn of various lengths. Find a tree outside and have the children attach the cards to the correct parts with pieces of yarn – a fun way to decorate a tree. Take extra cards and draw any parts that are missing, such as flowers, nuts or fruit. Add those to the tree where they might be found. Older children can discuss the function of each of the parts, such as roots hold up the tree (support) and bring water into the tree. (Scissors speed up card removal when you are finished.)

Sketching trees is a good way to learn the shape of different kinds. Claire Walker Leslie has an excellent guide to sketching trees (click on the Guide to Tree Sketching resource to download a .pdf file). Sketch a tree and label the parts if you can’t go outside.

IV. How Trees Grow – The Internal Parts of a Tree

See if you can find a “tree cookie,” a cross-sectional piece of wood through a tree trunk. These are often available at craft stores. Those with the bark still on are the best.

Internal parts of a tree:

• cambium – layer of active cells that divide to form inner bark and sapwood
• sapwood
• xylem – water carrying elements (in sapwood)
• phloem-food carrying elements (inner bark)
• heartwood

Look at the tree cookie and see how new rings are added each year. Explain how the tree only grows from the cambium and cutting it (for example by carving initials on a living tree), damages its ability to grow and live. A fun demonstration of how a tree grows might be to add layers of clothes to a doll or person, to show how the tree expands by adding layers. See if you can tell how old the tree that made the tree cookie was when it was cut down by counting the rings. (More information on internal parts).

We’ll continue with more activities next week. Until then, here are two sources of more information about trees:

Illinois Department of Natural Resources has  lesson plans in .pdf format

Arbor Day Foundation has education links and online games.

Hope you enjoy our celebration of tees this month. If you have any suggestions for activities or websites, please let us know.

Today is Arbor Day. Frankly, I am a bit sad. Why?

First of all, I am sad because this year my parents decided to log the small woods that is on their property. They knew I wouldn’t be happy, so they didn’t let it slip until it was already done. And they were right. I felt loss for the walnuts and oaks who had been standing since as long as I can remember. I miss them.

Arbor day also reminds me of the story of Herbie the elm tree, which is a poignant one. Rambling Woods has a good summary of the Herbie story.

Maybe I miss the trees more because here in the desert trees are small and shrubby. A big tree is a rare and beautiful sight.

In any case, a book that came in the mail this week struck a chord with me.

I will say up front that this is an adult book, it is not written for children.

Keepers of the Trees:  A Guide to Re-Greening North America by Ann Linnea has the details right. It is printed on recycled wood-free paper.

Linnea writes about the stories of fourteen men and women who are dedicated to conserving trees, including herself. She includes people from a diversity of outlooks, races, genders, lifestyles and backgrounds, all brought together by their love of trees.

The author has a compelling writing style and sets just the right tone. The book isn’t preachy or heavy-handed at all. Basically, it is about the people and their work.

People like Corella Payne, who researches public health issues such as asthma for her job, and then volunteers as a Treekeeper for public parks during her off hours. Corella sees the link between being outside with nature, and overall health and well-being.

The story of Merve the logger stands out in my mind because of my recent experiences. Merve has been selectively and sustainably logging the same spot in Canada for years. Although he has removed the same amount of timber that he would have gotten if he had simply clear cut, the forest remains in place, still viable and diverse. He respects the soil, leaves natural drainage systems intact and tries to take trees that are mostly at the end of their natural life cycle. Inspiring!

The layout of Keepers of the Trees is visually appealing, with many color photographs and figures. In the back is a list of practical things that you can do if you are interested in “tree-keeping.” Suggestions include planting a tree, adopting a tree, and mentoring a child.

I think I will take up that suggestion to mentor a child by taking my son to see another cork oak I found out about recently. Seems like the right thing to do on Arbor Day.

And if you are interested in helping a child learn more about trees, check my review of the Leaf and Tree Guide at Wrapped in Foil.

Edit: Tricia has a fabulous list of children’s books about trees at The Miss Rumphius Effect.

What are you doing for Arbor Day?

Please read the disclosure page for information about my affiliation with Amazon. Book was provided by publisher.

If you are interested in plants, the Festival of the Trees Blog Carnival is fun to browse through.

The newest carnival is up at Treeblog.

If nothing else, go see the fantastic photographs Ash found on Flickr.