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.

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.

The newest carnival is up at Treeblog.

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

Go on a nature walk and see if you can spot any of these spore-producing plants. Record where you see them and what the surrounding environment is like.

Mosses are low-growing plants with tiny leaflets. They coat the ground like velvet.

Ferns have leaf blades divided into many parts.

Photo from Flickr

Liverworts have rounded leaflets that are said to resemble the liver.

Horsetails have tall stems, with segments. Their leaves are long and fine, resembling a horse’s tail.

Did you find any of these plants?

Activity 2. Searching for spores.

Because these plants make spores instead of seeds, it is fun to see if you can find the structure that produces spores, the sporangium. If you don’t have any of these plants growing nearby, check with your local florist. They sometimes use ferns in bouquets.

See the dark dots on the underside of the frond? Those are the sporangia.

Check out this video of fern spore capsules shooting out the spores like a catapult!

The yellow brown structures on this moss are the sporangia.

What is the difference between a seed and a spore? A spore is a single cell, so it is tiny. In comparison, a seed contains many cells making up the embryo of the plant, the food that is stored with it, and a cover or coat.

Activity 3. Moss, horsetail, fern and liverwort habitats.

When you went on the nature walk, where did you find these plants? Did you find them mostly in wetter areas? Were any growing in the forest?

Did you find them growing together?

Ferns, mosses, horsetails and liverworts have somewhat similar growing requirements. Liverworts and mosses are considered to be non-vascular plants because they lack the special water-carrying tubes found in other plants. They must stay in relatively wet environments and can’t grow tall.

Aren’t these interesting plants?

Edit: If you are interested in learning more, take a look at Steve Parker’s Ferns, Mosses and Other Spore-producing Plants book, which is part of the Kingdom Classification series. I have a review at WrappedinFoil.

If you live where trees are deciduous, you might want to study the next step:  what happens to leaves when they fall off the tree?

First, think about and make a list of what you think might happen. Do you think some might be eaten, or that they will all blow away?

Scientists study the decomposition, or breakdown of leaves, by putting leaves in nylon mesh bags and letting them sit on the ground for long periods of time. The researchers come back every few weeks and pick up a few bags to take back to the laboratory. They open the leaf bags up and see what is happening. They look at things like how much weight the leaves lost, what kinds of critters have been eating the leaves, and how the leaves have lost chemicals (nutrients) over time.

You can make your own leaf bags (also called litter bags).

Gather:

• Heavy duty screen door nylon mesh (1 x 2 mm mesh size is best) or the nylon mesh bags that fruits or onions come in from the grocery store.
• Equipment, such as scissors, for cutting screen mesh
• Equipment for closing the screen bag: glue gun or sewing needle and thread (soldiering irons can be used by adults).
• Place you can safely leave leaf bags under trees and be able to retrieve them over time

If you are using the pre-made nylon bags from the grocery store, you can skip this step. If you are using screen door mesh, cut out strips 10 inches (25 cm) wide and cut into 8 inches (20 cm) sections and fold in half. Use the glue gun, needle and thread or soldiering iron to seal two sides. Leave one end open so you can put the leaves in.

Once you have the leaf bags made, go outside and fill them with leaves. Try to use freshly fallen leaves and collect only the leaves from under the trees where you will be leaving your bags. If the leaves are too dry, you can wet them with a bit of water to get them into the bags without crumbling. The grocery store bags will have larger openings, so you might want to use bigger leaves.

Close the bags with hot melt glue, or by sewing or tying them shut. Place the leaf bags outside in a place where you can safely retrieve them. You might consider marking the bags with sticks in the ground or tying the bags to brightly colored tent pegs shoved into the ground.

Now you have to be patient. Check the bags roughly every month and see how they are faring. Leave them under the trees until next year and then be sure to collect them. Open the bags into a tray or pan and sort through the contents. What do you think you might find?

For a scientific discussion of the procedures for studying leaf decomposition, check this Sewanee Leaf Litter Decomposition Manual.

Other fun activities for fall leaf drop season are to put the leaves back on the tree and exploring fall color.

Do you know what kind of tree this is?

We’d love to hear what you find in your leaf bags.

Edit: I just found three awesome ideas for using fall leaves at 5 Orange Potatoes. The first is laminating leaves to make leaf rubbing plates. The second is a game called odd leaf out. The third is making polka dot leaves.

Flipping rocks was somewhat disappointing at first. It has been the third driest summer on record in central Arizona, and because the summer is when we normally get most of our precipitation, we are really dry. The terms dry as a bone, parched, and desiccated come to mind.  Most of the rocks we looked under would normally have isopods (rolypolies), ants or earwigs, but we didn’t see any of those. Occasionally we might see a scorpion. We didn’t see any of those either.

What we did find was this:

Any ideas what might cause these white tunnels? I’ll give you a hint:  it isn’t a type of spider, although it is made of silk.

In fact, the tunnels are made by an insect. Here are some photos I took of one earlier this summer.

Does anyone remember what it was?

(If you want to find out the answer, check this previous post.)

All in all, we saw something we wouldn’t have otherwise seen, and realized how much the lack of rain is changing the environment for even tiny things that live under rocks. And best of all, we got outside and had some fun.

What did you find?

Basically you go outside and look under a rock or two. Record what you see by drawing, painting, taking photographs or recording in your nature journal. If you live where there might be poisonous creatures under there, like scorpions or snakes, use gloves and/or a bar to flip the rocks.

When you are done, carefully return the rock to its original position.

If you blog about it, let them know.

Now wasn’t that fun?

It was great fun and started an interest in developing a more formal nature journal. Although I am a scientist, I also love art and writing. Making a nature journal is a wonderful way to combine all three.

First I took a look at this book:

Drawn to Nature Through the Journals of Clare Walker Leslie by Clare Walker Leslie (see details below).

The book starts out with some simple and lovely ways to record the weather each day. This would be an easy and age-appropriate way for young children to get started creating a nature journal. Note: Weather observations would also tie in nicely with the upcoming book-based movie, “Cloudy with a Chance of Meatballs.”

Then I found this video about natural journals from my alma mater, SUNY College of Environmental Sciences and Forestry. Hey, I remember having dendrology labs in that cemetery (dendrology is the study of trees).

The Handbook of Nature Study blog is a wonderful place to explore journals and nature. I love to visit this site when I have plenty of time to look around at all there is to offer (which is not often enough, I’m afraid). This blog completes the exercises laid out in Anna B. Comstock’s classic Handbook of Nature Study.  Barb calls them “outdoor challenges.” Barb also has the Harmony Art Mom blog where she shows the art side of natural journals. This video is from one of her lessons.

Making a Leaf Rubbing For a Nature Journal

For a shorter reference, try The Nature Journal as a Tool for Learning.

The author of that article mentions the “Grinnell System,” which is a more formal method of recording observations used by scientists. Although I was able to find a site that discusses the Grinnell System, I am still going to look into it a bit more. Have you ever heard of it and/or used it? Do you know any references?

Science, art and writing, all rolled into one. Nature journals have it all.

Some books to look for:

Drawn to Nature Through the Journals of Clare Walker Leslie
by Clare Walker Leslie

Keeping a Nature Journal: Discover a Whole New Way of Seeing the World Around You
by Clare Walker Leslie, Charles E. Roth

Illustrating Nature: Right-Brain Art in a Left-Brain World by Irene Brady

That didn’t stay long, but a few days later we had a sweet little orange-crowned warbler who decided our back patio was a good place to find food. Its yellow belly and olive-green back really stood out. It would hop about between the flower pots catching insects.

Yesterday a female black-headed grosbeak came to visit our feeder. She has a striking black and white-striped head and a large beak, strangely out of proportion for the rest of the bird.

A few days ago my son noticed a pale bird visiting the feeder. With a string of new birds showing up, we excitedly pulled out the bird books. Nothing really seemed to fit, and the bird did look familiar. Very familiar. In fact it looked like all the house finch females that have come to our feeder for years.

You decide. The pale bird is on the right, a regular female house finch on the left.

We think she is an example of leucism, a bird or mammal with abnormally pale coloration.

Project Feeder watch has an article on Plumage Variations: Albinism or Leucism?

Stokes birding blog also has an article on leucistic birds.

Most of you probably noticed the two circular depressions. The creature at the bottom of those funnel-shaped pits is the larval stage of the ant lion, also called a doodlebug. Ant lions are found in warm areas throughout the world, including Florida and the southwestern United States.

If you were to dig out the bottom of the pit, you would find the ant lion larva, which looks a bit like a lacewing larva and the two are related. Here’s a photo of an ant lion larva from Iowa State University. Some species have even longer jaws.

The ant lion larva digs a pit in loose dirt or sand near ant colonies. They spiral around and around from the surface down to the lowest point, creating a steep and slippery slope. The ant lion prefers to dig in areas with fine sand, and maintains the pit by throwing out any pebbles or bits of plant that might fall in.

When an ant or other small insect falls into the pit, the larva flicks sand at it to knock it towards the bottom. Once the ant is within reach, the larva grabs it and drags it under the sand and eats it. Don’t feel too bad though, many times the ant is able to scramble out of the pit unharmed and the ant lion often goes hungry.

When the larva attains its full size, it pupates. The pupa is round and covered with a layer of silk and sand, similar to that of the lacewing. The adult ant lion emerges from the sand. It is slender with wings with many veins that fold back over its body when it is at rest. The adult might be mistaken for a damselfly or dragonfly. Firefly Forest has a fantastic photograph of an adult ant lion, go on over and take a look.

Have you ever seen an ant lion?

For more information: