Anna Maria Locke

Vegetation Dynamics Lab Tour!

Since I spend so much time in the Veg Lab for my research assistantship, I thought I would share a little bit of what I do with you!

Welcome to the lab...

We work on projects that deal with vegetation change (mainly forests, and mainly out west), such as how forests react to disturbances like fire and human activity.  Then the research results are used to develop management and restoration programs to return forest structures to their natural state.  Lots of research is also done to figure out what this elusive "natural state" really is, since humans have really screwed things up in the last 150 years!!

Some of the "evidence" we use to figure out this disturbance-restoration cycle are tree rings and fire scars.

Here is an example of a fire-scarred tree trunk:
It's a cross-section; the outside of the trunk is across the top and right side.
All the little bumps and vertical lines across the top dark part are fire scars.
This tree survived multiple fires and we can tell what years the fires occurred by dating the tree's rings!

This is a close up of a tree core that is used to analyze and date rings:

Each ring represents one year of growth. Some rings are bigger and some are smaller, based on how much rain fell in that year or how many other trees and bushes the tree was competing with to grow.
If we know that a particular year had a drought or lots of snow and rain, we can match those years with small and big rings on the core to date the rings and tell how old the tree is!
On the other hand, if a tree has lots of small rings followed by lots of bigger rings, it probably means the tree was stuck under bushes and bigger trees for a few years until it finally broke through to join the canopy and get more light.

We can analyze a set of tree cores to make a historical timeline and tell a story about what happened in the forest hundreds of years back!

Thousands of trees are cored at different sites for each project and the cores are stored in drinking straws:

These are the increment bores that are screwed into the tree trunk to carve out a core (it doesn't hurt the tree because it will just grow around the bore hole and heal itself like it does after a fire):

The orange one is for HUGE TREES and the unopened blue one is for small trees.
Just because a tree is big doesn't mean it is the oldest tree in the forest! They all grow at different rates, which is why the only way to tell the age of the forest stand is to sample and count tree rings. Mmmm lots and lots of work...

Back in the lab, we look at the cores under microscopes and use tools like calipers and rulers to measure growth and assign dates to the rings...

(see the weird marks on the slab of wood under the tree core mount? those are maple syrup tap scars!!)

As you can tell, it is a HUGELY LABOR INTENSIVE field of study!!

Luckily I like trees, so I think it is pretty interesting

I will post a geography lesson on the impacts of fire and Smokey the Bear later :)