treeS:  Wood, ID, & context

In this lab we will be looking at a type of growth form in plants that we see all around us...trees!  We will do some basic tree ID as well as understand a bit about the conditions in which certain trees tend to grow.  We’ll look at how a few key environmental patterns (soils, slope direction & aspect, and moisture) affect the spatial distribution of tree species around the Kessling Wetland. This is a great time of year to be looking closely at trees, as so much interesting biology is happening day by day, week by week.

In addition we we also be taking a close look at something you interact with every day but also likely take for granted...wood! There are many structures in wood that vary by species that give wood its distinct look and character.  Please don't feel that you have to know everything there is to know about wood as part of this lab.  The main purpose is to have you look at wood grain (something you see around you every day!) and focus in a bit more on the structures that are inside...and that different species and genera have different structural arrangements!  My hope is that you won't look at the edge of a wooden table the same ever again!

During this lab we will also talk about pruning and grafting and how a tree responds to management.  These are practical skills that also use a lot of botanical knowledge.  You can try grafting on almost any plant...some people graft tomatoes!  Pruning is usually done before vigorous growth initiates in the spring (but after the threat of freezing passes) but we can prune some robust currant bushes without any ill effects.

the lab activity

Part 1:  Tree ID & Context

This is one of the first things you learn about plants when you are young.  You look at trees, you look at their leaves, and you try to identify them.  There are also some other strategies that also become useful when identifying trees (i.e. the color of the bark when you cut into it, etc.).  Here are a list of trees that commonly grow around Kessling Wetland:

1. Black Walnut

• chambered pith

• dark pith

• dark nuts

• chocolate bark when hit

2. White Ash

3. Green Ash

   1. • • green half moon leaf scar

        • wetted area

4. Blue Ash

   1. • • square stem

5. Eastern Cottonwood

6. Sandbar Willow

7. Sugar Maple

8. Kentucky Coffee Tree

9. White Elm

10. Red Elm

11. Bitternut Hickory

12. Northern Red Oak

13. Black Oak

14. Eastern White Oak

15. Eastern Redbud

You will notice that some trees grow in the wet areas down by the wetland, others like the midslope of the hill, while still others like the well drained upland areas.  See if you can figure out which species tend to group in the wet areas, etc.  Also, you will notice that there are plenty of small Ash trees but larger older Ash trees are not present.  Why is this?  Work on both identifying trees but also placing them into their larger context around the Kessling Wetland.

Part 2:  Understanding Wood 

Before lab please take a look at one of these amazing online wood database (who knew there was such a thing!?!?!).  Namely - use the Inside Wood Library.  They provide multiple ways to search through the database.  I suggest using the "Search by Family" page.  You will see big differences if you pick a member from each genus below:  

• • • hickory (Family Juglandaceae; Genus Carya)

    • maple (Family Sapindaceae; Genus Acer)

    • oak (Family Fagaceae; Genus Quercus)

    • pine (Family Pinaceae; Genus Pinus)

Go down to the "Background" section on our lab webpage to learn more about the structures you are seeing in these images

• • • Are there distinct ring boundaries?  What do they look like?

    • Ring porous to diffuse porous - where is it in the continuum? What do you notice about the vessel elements?  What about the tracheids?

    • How distinct are the rays?  What do they look like?

    • Etc.....

Part 3:  Tree Management - Grafting and Pruning

Please watch the grafting and pruning videos below in the "Background" section.  Class won't go on long enough for you to see the results of any grafting or notching you do.  Instead you will practice pruning and grafting and understand the botany concepts behind these techniques.

Skill(s) to Master for Practicum

Note - there are a lot of tasks in this lab.  Please listen to your instructor regarding which skills are important for the practicum

1. Identifying trees using leaves, bark, and their environmental context

2. Familiarity with the structures in wood and their functions as well as how these structures differ across genera

3. Demonstrate pruning and grafting techniques and explain the botany concepts behind these techniques

background

Part 1:  Tree ID

Here is a list of Tree ID websites in addition to the apps you already are familiar with.  There is some jargon and nomenclature to learn to use these keys but many of them have great pictures and diagrams to help you sort it out.  If you need some additional help here is a slideshow from Merry Lea's Bill Minter.  This is not an exhaustive list, just some I have found (no particular order):

• Urban Tree Key

• North Carolina State Tree Key

• Iowa State University Tree Key

• Oregon State University Tree Key

• Multiple resources from Wisconsin to ID trees

• What Tree?

Some characteristics you may want to pay attention to are as follows:

• leaf characteristics

• twig characteristics

• bark characteristics

• tree form

• growing habit

Part 2: Understanding Wood

A list of resources containing samples of wood for comparison

1. Inside Wood Library

   • • search page

       • • by Family

         • by Image

     • multi-access key

2. Identification of Common North American Woods

List of terms (with live links) that will help you in understanding what you are seeing when you look at wood...make sure you know these terms!

• • Fibers

  • Tracheids

  • Vessel Elements

    • • Perforation Plates

  • Ray Cells

  • Parenchyma

  • Resin Canals

    • • Click Here for examples of all these structures

  • Ring-porous

  • Diffuse-porous

  • Medullary Rays

  • Springwood (earlywood)

  • Summerwood (latewood)

List of terms (with live links) that will help you in understanding what you are seeing when you look at wood...make sure you know these terms!

• Fibers

• Tracheids

• Vessel Elements

  • Perforation Plates

• Ray Cells

• Parenchyma

• Resin Canals

  • Click Here for examples of all these structures

• Ring-porous

• Diffuse-porous

• Medullary Rays

• Springwood (earlywood)

• Summerwood (latewood)

Part 3:  Pruning & Grafting

other resources...

• Heartwood

• Sapwood

• Pith

• Vascular Cambium

• Bark

  • Living Phloem

  • Periderm

    • Cork & Cork Cambium

• Extractives,  also here

• Cellulose

• Lignin

• Cells