Although most of the leaves have fallen, the dormant season can be the easiest time to identify trees with a bit of practice.
Many people pride themselves on their skill in identifying trees. The curious might want to know which species grow in their yard or a nearby park. Sometimes, people simply have a heightened ecological conscience and just want to know. For whatever reason, tree ID can be done year-round.
Michigan boasts around 100 tree species, depending upon how a tree is defined. It’s impossible to fully understand a forest without knowing “who” grows there. Trees are not the only life form, of course, but they are the dominant life form and impact everything that occurs in the forest. And of course, it’s difficult to fully appreciate the amazing natural resources of Michigan without considering forests.
There are about a dozen characteristics available to help identify trees. Learning which subset of characteristics to use for a particular tree is where practice and skill are needed. Some characteristics are seasonal, such as leaves, fruits, and flowers. Most others are more year-round, such as twig and branching patterns, buds, bud scars, bark, tree form, site, and tree associates.
For some trees, paper birch for instance, most people only need to look at the white, peeling bark. Easy. Although, sometimes pale versions of quaking aspen have been mistaken for paper birch. Trees with acorns are one of several oaks. Most of our conifers carry needles year-round.
Many people refer to all conifers as “pines” when, actually, most conifers are not pines, especially in the U.P. Pines make up about 44 percent of the conifer volume in Michigan (14 percent of total tree volume) and about 25 percent in the U.P. (11 percent of the total). Northern white-cedar is the most common conifer in Michigan. It’s not a pine! Neither are hemlocks, spruces, firs, tamaracks or larches.
Because there are only about a dozen common conifers (only four are pines!) in the forest, conifer ID is fairly easy. It’s a good place to begin in order to build some confidence and skill.
Another good tactic for beginners is learning the ten most common tree species first; sugar maple, red maple, white cedar, red pine, white pine, northern red oak, quaking aspen, bigtooth aspen, black cherry and hemlock. Once these trees are known, comparing them to unknown species will often make the identification process move quicker.
Using seasonal characteristics is another good way to learn to identify trees during the “off” season. Finding remnant cherries go a long way to segregating the cherry species. While doing that, it’s a good time to observe other key features, such as bark patterns and buds. Understory trees that still have some brown leaves well into the winter are likely to be either beech or ironwood.
A tree with an opposite branching pattern narrows the choices down to maples, ashes and dogwoods. Once you know that, it’s not too difficult to use a field guide to learn the individual species. However, make sure you have a tree and you’re not looking at a shrub. Some of our shrub species also have opposite branching.
Leaves are a popular way to learn tree species, and they’re a good technique during the growing season. Naturally, some tree species have variable leaf characteristics, so be cautious. Use multiple samples from the same tree to get an “average” appearance. Using fallen leaves takes special care to make sure the leaves fell from the tree that you’re looking at.
Considering “where” the tree grows can be quite helpful, especially for sites that are particularly dry or wet. A pine on a dry sandy plain will most likely be jack pine. A broad-leafed tree in a swamp will likely be black ash or one of the elms. Black and white spruce can be difficult to distinguish by needle appearance, but if it’s in a lowland site, it’s probably black spruce. If the site is upland, it’s probably white spruce.
The more trees you know, the easier it is to learn more. One of the best field guides is “Trees of Michigan” by Linda Kershaw. Norman Smith’s “The Trees of Michigan and the Upper Great Lakes” is also good. For the U.P. and nearby regions, the U.P. Tree ID website is good. Happy hunting.