September 18: Trees, Trees, Trees

"Be like the fox
who makes more tracks than necessary,
some in the wrong direction.
Practice resurrection.” ― Wendell Berry

The setting where I work, live, and teach

Tuesday September 18:
tree identification, talking trees, dichotomous keys, leaf color experiment
(Sources: Once There Was a Tree by Natalia Romanova, Sharing Nature with Children by Joseph Cornell, Oregon State University Dichotomous Key, PBS Nature: What Plants Talk About (video clip))

Materials:
Once There Was a Tree by Natalia Romanova, lodge pile pine branch/cones, Oregon State University Dichotomous Key, PBS Nature: What Plants Talk About (video clip), backpack, radio, first aid kit, field guides

Objective:  Student will begin to understand more about the shapes, adaptations, life cycle and categorizations of trees, developing a greater sensitivity to the complicated ecosystem they inhabit.

Class introduction/hook:
Blind tree identification activity

M's drawing, done by feeling, (not looking
at) a lodgepole pine cone

Today, we started science with a story: Natalia Romanova's lovely book, Once There Was a Tree, a story about a tree stump that becomes a habitat to bark beetles, maggots, ants, bears,birds, frogs, earwigs, and men.  I love the art and M loves the rhythm of the story.  It puts the tree in the context of its ecosystem but uses narrative instead of stiff scientific language.

After we read, M and I did an activity inspired by some of the curriculum I received as a naturalist.

Before class, I gathered some needles and cones from a nearby pine.  I placed them in a cloth sack.  During class, I instructed M to close his eyes, reach in, and feel the objects in the sack.

"I know!  It's a pine cone."

I then asked him to try to draw what he felt without looking at the pine cone.

"Can I keep my hand on it?"  He asked.

"Yes."  I said.

After M finished his drawing, he looked at the pine boughs and cones inside the sack and used Oregon State University Dichotomous Key to identify them as part of a lodgepole pine.  Lodgepole pines have long needles in clusters of two and small egg-like cones.

We watched a short video--PBS Nature: What Plants Talk About--which explored the systems formed around old growth "mother" Douglas Firs.  We watched a scientist from British Columbia explain temperate rain forest root systems, tree cooperation, and symbiotic relationships between firs and fungi.  M and I were transfixed.  The world is wonderful.  We're lucky to be wandering in it.

Then M and I went outside to identify more trees.  We brought a bag to collect leaf and needle samples.  We walked and sung and took photographs as we hiked.  We talked about the macro function on my camera and M photographed tree branches and fungus.  We discussed nurse-logs and M climbed in a tree stump with no heartwood remaining.  We gathered tree samples and walked the river bed.

Some days teaching M illuminates how little I know.  He asks questions, all the time, great questions that make me wonder at what age we stop analyzing the world with so much care.  For example, during an experiment we did later in the day, M asked, "What is rubbing alcohol?" and I realized I could describe what rubbing alcohol does but that I didn't know what it was.  (Later, I looked it up and learned that rubbing alcohol is a mix of isopropyl alcohol [C3H8O or C3H7OH--produced by combining water and propene in a hydration reaction] and ethanol.)

Shredded leaves in alcohol, part of our leaf color experiment

We returned to the library with our tree samples (needles, cones, bark) and began to use  the Oregon State University Dichotomous Key to identify the samples we'd taken.  I got really frustrated trying to correctly identify what I knew to be a Western Red Cedar, only to realize that the Western Red Cedar is a false cedar and that there are no true cedars native to Washington.  M and I also struggled trying to recall all of the properties of the tree samples we were trying to identify from the samples we collected.  It would be much easier to do the identification on-site.  After class I ordered a dichotomous key in book form.

M and I finished our morning science by doing an experiment to illustrate why leaves change color.

We collected and shredded green leaves from a nearby tree.  We then covered them in rubbing alcohol, mashed up the leaves, covered the jar, and sat the container of leaves in a bowl hot water.

After the jar of shredded leaves had been in the water for almost an hour, we cut strips of paper towel and taped them to the jar in such a way that the ends dangled in the leaf/rubbing alcohol solution.  If the experiment is done correctly the alcohol should climb up the paper bringing not only green color pigment but yellow and orange color pigment with it, illustrating the other pigments present in leaves that chlorophyll typically hides (until plants stop producing it in autumn.)

Unfortunately, when I looked at our jar at the end of the day, I only saw green pigment climbing up the paper towel.  Alas.  Perhaps M and I can retry later to see if we get different results.

M's hiking pictures:

Washington State Content Areas Covered:

EARL 1: System
Big Idea: Systems
Core Content: Role of Each Part in a System

Students know that:

-A system is a group of interacting parts that form a whole. Give examples of simple living and physical systems (e.g., a whole animal or plant, a car, a doll, a table and chair set).
-A whole object, plant, or animal may not continue to function the same way if some of its parts are missing. Predict what may happen to an object, plant, or animal if one or more of its parts are removed (e.g., a tricycle cannot be ridden if its wheels are removed).*
-A whole object, plant, or animal can do things that none of its parts can do by themselves. 
-Some objects need to have their parts connected in a certain way if they are to function as a whole. 
-Similar parts may play different roles in different objects, plants, or animals.

Students are expected to:
-Explain how the parts of a system depend on one another for the system to function. 
-Contrast the function of a whole object, plant, or animal with the function of one of its parts (e.g., an airplane can fly, but wings and propeller alone cannot; plants can grow, but stems and flowers alone cannot).
-Explain why the parts in a system need to be connected in a specific way for the system to function as a whole (e.g., batteries must be inserted correctly in a flashlight if it is to produce light). -Identify ways that similar parts can play different roles in different systems (e.g., birds may use their beaks to crack seeds while other birds use their beaks to catch fish).

EALR 2: Inquiry 
Big Idea: Inquiry
Core Content: Conducting Investigations

Students know that:
-2-3 INQA Question: Scientific investigations are designed to gain knowledge about the natural world.
-2-3 INQB Investigate: A scientific investigation may include making and following a plan to accurately observe and describe objects, events, and organisms; make and record measurements, and predict outcomes.
-2-3 INQD Investigate: Simple instruments, such as magnifiers, thermometers, and rulers provide more information than scientists can obtain using only their unaided senses.

Students are expected to:
• Explain how observations can lead to new knowledge and new questions about the natural world.
• Work with other students to make and follow a plan to carry out a scientific investigation. Actions may include accurately observing and describing objects, events, and organisms; measuring and recording data; and predicting outcomes.

EALR 4: Life Science 
Big Idea: Biological Evolution (LS3)
Core Content: Variation of Inherited Characteristics

Students know that:
-2-3 LS3A There are variations among the same kinds of plants and animals.
-2-3 LS3B The offspring of a plant or animal closely resembles its parents, but close inspection reveals differences
-2-3 LS3C Sometimes differences in characteristics give individual plants or animals an advantage in surviving and reproducing.

Students are expected to:
• Give examples of variations among individuals of the same kinds of plants and animals within a population (e.g., tall and short pine trees, black cats and white cats, people with blue eyes or brown eyes, with freckles or without).
• Compare the offspring of a plant or animal with its parents, listing features that are similar and that are different.

 • Predict how differences in characteristics might help one individual survive better than another (e.g., animals that are stronger or faster, plants or animals that blend into the background, plants that grow taller or that need less water to survive).