Tree Ring Lab-Submit on Paper

TREE RING LAB

Bio Standard: 1.4  Develop an argument from evidence for how ecosystems maintain relatively consistent numbers and types of organisms in stable conditions.  Empahsize how changing conditions may result in changes to an ecosystem.

Lesson Clarity:

What I will be learning..... 

I will be learning how to count and evaluate tree rings and how they are a historical calendar for climate stability and change.

Why I will be learning this....

So that I can understand how climate is actually measured over time and how the earth keeps a natural calendar of climate in trees.  I will understand stability and change of ecosystems.

How I will know I learned it....

I will know how to find the age of a tree, fire scars, bug damage, and wind effects in tree rings. 

As we learned in our study guide on Fire Ecology  scientists often study tree rings to understand historical weather, climate, fire, and other disasters.  A tree is a long term historical record of nature.   They can look at living trees, trees that are the beams of ancient human structures, or even fossilized wood to see how climate and weather have changed over the years.   Dendrochronology is the study of tree rings.

Remember Climate is a long term average of weather in a region; about 30 years are averaged together to  determine "climate". Weather is today or recent. 

Tree Rings:

A tree ring, representing one year, consists of two layers:

• A light colored layer which forms in the spring and early summer, which is typically thicker because the tree is growing. 
• A dark colored layer which forms in late summer and fall, which is typically thinner because the trees growth slows

At locations where tree growth is limited by water availability, trees will produce wider rings during wet and cool years, than during hot and dry years. Drought or a severe winter can cause narrower rings too. If the rings are a consistent width throughout the tree, the weather was the same year after year. By counting the rings of a tree, we can pretty accurately determine the age and health of the tree and the growing season of each year.

Observing tree rings from bore samples or cross sections, a sort of "bar code" can be made and compared to other trees.  By comparing the bar code of many trees scientists have been able to study the climate as far back as 10,000 years.  If a person knows the species of tree, longitude and latitude, one can study the International Tree-Ring Data Bank (ITRDB), the world's largest public archive of tree ring data.  https://www.ncei.noaa.gov/products/paleoclimatology/tree-ring

There scientists collectively gather tree ring data for comparison for the study of Paleoclimatology- ancient climate. 

https://www.youtube.com/watch?v=xmZO7aRgcW4

https://www.youtube.com/watch?v=QBvHjSckV94

Procedures:

1. Pair up with a lab partner. 

2. Get two printed copies of the lab sheet.   THIS LAB NEEDS TO BE DONE ON PAPER, NOT ON CANVAS.  Each Partner will need to turn in their own lab sheet.

3. Watch both the video links above. 

3. Look at Cross section of Sample A on the front table. You will have to take turns at this. Note: except for Cross section A, all of these cross sections were cut in 2022.

4. For the sake of having enough sections to study, our tree sections will be marked with fire scar, rather than actual fire scars.  

Safety:

The hazards in this lab are very low. No gloves, goggles, or aprons will be required.  Treat all science equipment and science samples with respect.  Walk carefully with probes and do not horse play!  Noise level for this lab is 2-3.