What do you need to core a tree?
Supplies to find your study site & make measurements
- a dbh tape (also called "d-tape") - a tape measure that is calibrated so when you stretch it around the tree, you read the diameter, or distance through the tree. Because you’re measuring the diameter at breast height, it’s called a dbh tape
- plastic flagging – comes in pink, orange, and other bright colors that you can see through the woods. Used to mark your trees, plot boundaries, etc. Dr. Grissino-Mayer recommends wrapping some of this around the ends of your tools, too, so you can see them
- dendrometers – a tool used to measure how quickly a tree is growing in the field. A dendrometer band is an open metal ring (like an expandable bracelet) placed around a tree’s trunk. A spring connecting the ends of the metal allows the tree to expand under the band, and marks on the metal show how much the tree has grown from year to year
- dendrograph - another tool to measure tree growth in the field
Supplies to core the tree
- increment borer starter (optional) - a plate that fits between your chest and the borer that you will use to take the sample. The starter holds the borer steady while you get it started in the tree
- increment borer - to bore a pencil-shaped section out of a tree. A borer is like an auger; it's an instrument with a hollow shaft that is screwed into the trunk of a tree, and from which an increment core (or tree core) is extracted using an extractor (a long spoon inserted into the shaft that pulls out the tree core).
Recording your data
- tree-ring sample form
- waterproof field notebooks
- permanent black felt-tip markers—fine-point and thick-point
Keeping your cores safe
- plastic wrap – to hold together pieces from a cross section of a tree
- 2" strapping tape (optional) - ideal for holding together pieces from a cross section of a tree, if you don't have any plastic wrap (see above)
- core mounts – to secure and display cores
- straws – to hold your cores
- map tubes – to hold the straws that are in turn holding your tree cores
Supplies to keep your other supplies in tip-top shape
- Oil lubricant/protectant to keep your increment borer clean and rust-free
- a sharpening kit - for your increment borers, a must in the field
Back at the lab
- sanding supplies - sandpaper, finishing film, belt sanders, band saws, hand planers
- beanbags - tiny beanbags about 2-3" long to hold and position your increment cores on the measuring stage
- dissecting probes – sharp tools with handles (similar to what your dentist uses on your teeth) to mark decadal rings of wood once they've been crossdated: one tiny hole for each decade ring (e.g., 1960, 1970, 1980, etc.), two for each 50th year (e.g., 1850, 1950, etc.), and three for the century years (e.g., 1700, 1800, 1900, etc.)
- graph paper - to graph narrow tree rings when you construct a diagram called a skeleton plot
- mechanical pencils – to make preliminary markings on your tree rings before using the dissecting probe
- single-edge ("Treat") or double-edge razor blades - these are used to put a clean, flat surface on a core, but this takes practice. Don't attempt to surface a core with a razor unless you've been trained!
- artists’ (or "gummy") erasers - place these between your fingers and small strips of your sandpaper when fine-sanding your increment cores. Also good for erasing mistakes on your skeleton plots as they don't chew up the graph paper
- steel wool (fine) - used to remove resin from a very resinous increment core. Burnish the surface lightly, and the rings will appear!
- scissors - to cut your graph paper, glue - to glue down your cores on wooden mounts, string or masking tape - to hold the cores tight on the mount as they dry
According to Dr. Grissino-Mayer, you might also need:
- archaeological tools
- measuring systems - Velmex or Lintab
- densitometry equipment – to measure the density of a tree
- chain saws – to access sites and take “slices” of dead trees
This information is adapted from Dr. Henri-Grissino-Mayer’s webpage. You can read more about supplies and fire history research here.
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