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Anyone Can Observe Trees!

The REU program may be remote this year, but urban and suburban trees can still provide a welcome opportunity to get out in the field. Last week, we measured and identified trees in our neighborhoods, and this week, we will take a closer look at their health. Below, you can see me measuring a Norway maple (Acer platanoides). This tree was so large I had to get help in order to wrap my measuring tape all the way around its trunk!

I measured a Norway maple by wrapping DBH tape around its trunk.
Thanks, Dad!

New to observing trees? Here are a few tips to help you get started.

Look at the leaves. 

Leaves are one of the most variable parts of a tree and one of the best places to start looking for an ID. When you find a new tree, ask yourself some questions about the leaves. Are they needle-like, scale-like, or broad and flat? Are the leaves attached to the branch directly opposite one another, or do they alternate? Are the leaves individual (simple), or are there many leaflets linked to one central axis (compound)? (Hint: there will always be a small bud present at the base of a leaf. Otherwise, you're looking at a leaflet!) This guide provides an overview of some of the major leaf shape categories to look for. Don't be intimidated by the vocabulary - you'll pick up many of the terms naturally as you get used to observing trees. To start, just focus on describing what you see in your own words.

Look at the bark.

What color is it? What texture? Does it have a regular pattern? Some trees are actually easiest to ID by their bark. For example, the American sycamore (Platanus occidentalis, aka the species I’m studying!) has peeling bark that makes it distinctive even in the winter.

Basswood trees bloom in mid-summer.
Bracts are actually modified leaves.

Look at the seeds or flowers.

These aren’t always present, but they’re a big help when they are! Above is a picture of basswood (aka linden or lime, Tilia spp.) buds. In this example from my neighborhood, you can see several hard, round buds attached to a yellow-green bract. Look for heart-shaped, asymmetrical leaves to confirm your ID.

Interested in learning more?

There are other features that may be useful for identifying a tree, like tree shape, habitat, and even smell. Check out these resources to learn more.

The Arbor Day website has an illustration-filled guide to trees across the United States. The Seek app provides a great way to identify plants, animals, and fungi on the go. And finally, the Morton Arboretum has an online tree identification course and a searchable list of common trees, shrubs, and other plants.

Stay safe, and happy observing!