Plant Nature Study II by Jacob Joshua Levison Plant Nature Study II by Jacob Joshua Levison    

Lesson 9: Deciduous - The Butternut

Directions

Study the lesson for one week.

Over the week:

• Read the lesson.
• Review the synopsis.
• Recite aloud the vocabulary words and their definitions.
• Learn the concepts.
• Complete the enrichment activities.
• Study the review questions.

Synopsis

This lesson covers the Butternut tree, which belongs to the same genus as the walnut tree and also has its pith divided into chambers. The butternut tree produces nuts, but they are elongated compared to the walnut. Its leaves are lighter and have fewer leaflets than the walnut tree. The scientific (Latinized) name of the butternut tree is Juglans cinerea.

Vocabulary

Concentric: Having a common center.
Dendochronology: The science that uses the spacing between the annual growth rings of trees to date their exact year of formation.
Growth Ring: Any of the concentric rings formed in the trunk of a tree by the annual growth of wood.
Climate: The long-term manifestations of weather and other atmospheric conditions in a given area or country, now usually represented by the statistical summary of its weather conditions during a period long enough to ensure that representative values are obtained (generally 30 years).
Weather: The short-term state of the atmosphere at a specific time and place, including the temperature, relative humidity, cloud cover, precipitation, wind.

Concepts

GROWTH RINGS and DENDROCHRONOLOGY

1. Examine the cross section of a tree trunk.
2. Note the concentric rings, which share a common center.

These concentric rings are called growth rings.

1. As trees progress through the seasons (e.g. winter, spring, summer, fall) their rate of growth changes.
2. This annual change in growth results in the visible rings.
3. Each growth ring has a light part (fast growth early in the growing season) and a dark part (growth at end of growing season).
4. Each ring corresponds to one year.
5. To determine the age of the tree, count the number of dark lines only.
6. Count the rings on the illustration to mark off seven years of growth.

7. New saplings grow much faster than older trees, so the rings tend to get progressively thinner over time.

When studied by scientists (dendrochronologists), these rings reveal information about the history of the tree.

1. Scientists are able to determine the exact year each ring was formed.
2. Scientists can also determine information about the weather and atmospheric conditions for a given ring and year.
3. Scientists use the growth patterns to calculate climate statistics over longer periods of time (at least 30 years).
4. For example, in rainy years the trees tend to grow well and create thicker growth rings (controlled for age and other factors).
5. In dry seasons trees do not grow much and have thinner growth rings (controlled for age and other factors).

Enrichment

Activity 1: Narrate the Lesson

• After reading or listening to the lesson, narrate the lesson aloud using your own words.

Activity 2: Study the Lesson Pictures

• Study the lesson pictures and describe how they relate to the lesson.

Activity 3: Take a Nature Walk

• Bring a small sketchbook and embark on a nature walk.
• Seek out the stump of a relatively young tree.
• Sketch out the cross-section of the trunk including the growth rings.
• Count the growth rings. About how old was the tree when it was cut down?

Activity 4: Complete a Field Book Entry   

After your nature walk, complete page 19 in 'Science Field Book for Fourth Grade.'

Review

Question 1

A tree has eighteen growth rings. How old is the tree?

1 / 4

Answer 1

A tree adds a new growth ring each year, so the tree is eighteen years old.

1 / 4

Question 2

Why do the growth rings get generally become thinner as you move outward from the center of the cross section of a tree trunk?

2 / 4

Answer 2

New saplings grow much faster than older trees, so the rings tend to get progressively thinner over time.

2 / 4

Question 3

Why do growth rings tend to be thinner during times of drought?

3 / 4

Answer 3

Growth rings tend to be thinner during times of drought because a lack of water slows tree growth.

3 / 4

Question 4

How do weather and climate differ?

4 / 4

Answer 4

Weather is temperature, humidity, precipitation, etc. at a specific point in time. Climate is a statistical average of conditions over a long period of time (generally 30 years).

4 / 4

❮ ❯

1. A tree has eighteen growth rings. How old is the tree? A tree adds a new growth ring each year, so the tree is eighteen years old.
2. Why do the growth rings get generally become thinner as you move outward from the center of the cross section of a tree trunk? New saplings grow much faster than older trees, so the rings tend to get progressively thinner over time.
3. Why do growth rings tend to be thinner during times of drought? Growth rings tend to be thinner during times of drought because a lack of water slows tree growth.
4. How do weather and climate differ? Weather is temperature, humidity, precipitation, etc. at a specific point in time. Climate is a statistical average of conditions over a long period of time (generally 30 years).

References

'Studies of Trees' by Jacob Joshua Levison. gutenberg.org/ebooks/16116. n.p.

'Dendrochronology.' Wikipedia. Wikipedia.org. n.p.

'Secondary Tree Growth by Chiswick Chap (CC BY-SA 4.0)' Wikimedia Commons. commons.wikimedia.org/wiki/File:Tree_secondary_growth_diagram.jpg. n.p.

'Juglans Cinera 01 by H. Zell (CC BY-SA 3.0).' Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Juglans_cinerea_001.JPG. n.p.

'Juglans Cinera 02 by H. Zell (CC BY-SA 3.0).' Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Juglans_cinerea_002.JPG. n.p.