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So this lab is about something you probably see every day but don't think much about...wood! There are many structures in wood that vary by species that give wood its distinct look and character. During this lab we will look in detail at these structures. We will also talk about pruning and grafting and how a tree responds to management.
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!
the lab activity
the lab activity
This is activity has two parts:
Part 1: Understanding Wood Anatomy
For Part 1 we will be using an amazing online wood database (who knew there was such a thing!?!?!). Below a few of these databases are linked. They provide multiple ways to search through the database. We will be using the Inside Wood Library, specifically the "Search by Family" page. For Part 1 you will:
Look up TWO representatives from each genus below. You are going to want to copy the best images from each specimen that illustrate what you want to discuss according to the instructions below:
hickory (Family Juglandaceae; Genus Carya)
maple (Family Sapindaceae; Genus Acer)
oak (Family Fagaceae; Genus Quercus)
pine (Family Pinaceae; Genus Pinus)
Comparison #1 - Differences within Genus: Look at the two representatives for each genus. How much variability is there in wood structures within this genus based on the specimens you chose? Do you have any idea what might drive this variability between species?
Comparison #2 - Differences across Genera: So the first comparison was looking at 2 species within a genus and looking at differences. Now I am asking you to look at uniting characteristics within a genus and seeing how the 4 genera above are distinct from each other based on wood characteristics
When comparing both within genus (comparison #1) and across genera (comparison #2) here are some questions to help you sort through the differences. You will need to familiarize yourself with some of the vocabulary - links and images in the background:
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 2: Tree Mangement - Grafting and Pruning
For Part 2 please watch the grafting and pruning videos below in the Background section. Understandably I do not assume that all your folks have access to grafted trees. Also, class won't go on long enough for you to see the results of any grafting or notching you do. Instead fulfill these two tasks:
Task 1: Do some notching on a tree or bush near you. Pay close attention to where the buds are and your cutting of the thin green cambial layer. Make a prediction about what will happen - watch throughout the growing season how it responds to your notching
Task 2: Go online, find a grafting technique, think about how a toilet paper tube illustration would work. Create a very quick and simple YouTube video about how you would demonstrate this with a model (toilet rolls, paper, whatever you have and seems appropriate for your purposes).
what to hand in on your website
what to hand in on your website
A section describing your results for comparison #1. Make sure you include images that can be referenced for your comparison. [15 points]
A section describing your results for comparison #2. Make sure you include images that can be referenced for your comparison. [25 points]
One short paragraph (with photos) describing your notching and what you predict will happen as the growing season progresses [5 points]
A simple YouTube video describing a grafting technique [15 points]
background
background
A list of resources containing samples of wood for comparison
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!
Click Here for examples of all these structures
Ring-porous
Diffuse-porous
Springwood (earlywood)
Summerwood (latewood)
A closer look at ray cells
A model of a slice through a ring-porous tree, such as a deciduous oak. In ring-porous trees the early wood formed in spring contains wider vessels than the wood formed later in the year. The later wood is therefore denser and slightly darker and results in an obvious annual growth ring. In diffuse-porous trees there is little or no difference in vessel width between the late and early wood, as in horse chestnut, Aesculus hippocastanum. Some hardwoods are intermediate, for example the earlier vessels may be wider but dispersed among narrower later vessels. Conifers lack this type of vessel and have narrower tracheids instead and are neither ring-porous nor diffuse-porous.
A closer look at structures within a hardwood
A closer look at structures within a conifer
This is a VERY complex diagram tying everything together that we have been learning about wood anatomy. Please note that this diagram is looking at a leaf (top of leaf to the right, bottom of leaf to the left) - many of these structures carry from the wood all the way out to the leaf!
A very basic introductory grafting video
Whip and Tongue Graft
Crown Graft
A follow-up on the first grafting video with a bit of botany information
Apical dominance - you can manipulate a tree such that it prioritizes growth from different buds
Trees and growth hormones
Task 1: Do some notching on a tree or bush near you and watch throughout the growing season how it responds to your notching
Task 2: Go online, find a grafting technique, think about how a toilet paper tube illustration would work
Cool video of bud patch grafting and description of apical dominance and notching
If you are curious how the bud patch worked out here is the follow-up video
ABC's of Pruning
Just for fun - growing your furniture!
other resources...
other resources...
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