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Speaking of Nature

Speaking of Nature: The great exception

One of the benefits of being a teacher is learning. In order to teach a thing, you must first know it; but even then, a student can ask a question that catches you by surprise. Young minds, unfettered by what they know, can often ask completely ridiculous questions that turn out to accidentally (and occasionally brilliantly) shed light on a well-worn topic from a new angle. Other times I learn by figuring out why they don’t understand something.

My environmental science class recently had an exam on biomes. For those of you not enrolled in the course, a biome is a broad swath of the Earth’s surface that has a similar set of environmental conditions — specifically climate and precipitation. Even if these areas are on opposite sides of the planet, similar climate and precipitation will produce plant communities that are also similar. Examples of biomes you may have heard of are deserts, rain forests and tundra.

One of the subheadings in our textbook was simply labeled “forests” and, according to the authors of this particular text, there were three main subdivisions of forest: tropical, temperate and polar. I found the rest of this particular book to be a little simplistic, but that’s often a problem with textbooks. The tropical forests all turned out to be tropical rain forests, the temperate forests turned out to be temperate deciduous forests and the polar forests all turned out to be coniferous evergreen forests. But there are always exceptions to the rules, aren’t there?

Now many of my students are clearly brilliant people, but many of them have no real concept of anything regarding nature or the environment. This is why I enjoy teaching this class so much! Terms that I know very well (e.g., deciduous, evergreen, conifer, etc.) are completely new to them and, as a result, they tend to think in terms that are very black and white. A tree with broad leaves is always deciduous, whereas a conifer is always an evergreen. But then those annoying exceptions pop up and confuse them.

Take the term “evergreen” as an example. My students understand that trees that are called “evergreen” always have leaves, but they don’t understand that they aren’t necessarily the same leaves throughout the life of the tree. A great example of a local evergreen is the white pine (Pinus strobus), which also happens to be a conifer (a tree with long, needle-shaped leaves that bears cones). White pines always have green needles on them throughout the year, but the trees will drop about one third of their needles in October.

Then there’s the idea that all trees with broad leaves are deciduous, which means they drop all of their leaves at some point during the year. If you head to the forests of the Amazon basin or the island of Borneo, you will find broad-leaved trees that are also evergreens because they never shed all of their leaves at the same time.

But the greatest confusion arrives with the idea that some conifers aren’t evergreens. This is confusion only because of inexperience. Most of my students, who are 17 or 18 years old, lump all evergreens into the “pine trees” category because that’s all they’ve ever learned. When I start talking about pine, hemlock, spruce and fir, they adopt that confused, vacant look that I’ve become very familiar with. Throw in the term “larch” and you might actually do some damage!

But that is the great exception to the rule of deciduous conifers in our local trees. The eastern larch (Larix laricina) is also known as the tamarack, but both names are equally acceptable in this part of the country. If you lived in the northwestern U.S., you might run across another larch called alpine larch (L. lyalli) in Washington, Idaho and Montana. The western larch (L. occidentalis) is found more commonly in the same basic areas, as well.

Here in the Northeast, however, we have only the tamarack and it turns out to be our only native conifer that is also deciduous. During the summer, the trees might go completely unnoticed, or may simply be seen as some sort of pine. The tamarack is actually a member of the pine family, so this is quite reasonable. The only hint that they are different is their surprisingly soft and supple needles.

In October, the entire tree will start to turn a gorgeous golden orangish yellow and will stand out from any other conifer that might be nearby. Because there are so many other trees that change color in October, there may still be some chance that the tamarack will simply blend in to the general background of splendor that is the New England landscape in the fall; but in November, there is no more hiding.

Most of the deciduous broad-leaved trees (maples, birches, hickories, etc.) have now lost their leaves, but the tamaracks continue to hold on to their needles. As time passes, the color of the needles will deepen from a lemon yellow to a caramel orange. This is actually the best time of year to find tamarack trees if you can get up to a high lookout and scan the landscape with binoculars.

Many people will intentionally plant tamaracks for their beautiful appearance and I remember meeting a reader at one of my book signings who told me a very sad story. A house that had been in the family for many, many years was rented out to help raise money. The new tenants were very responsible and did a great job of taking care of the property. But they simply didn’t know everything they needed to know.

The house featured a stand of huge, healthy tamarack trees that were the pride of the homeowners. As the years passed, the tamaracks simply got bigger and more beautiful, but the renters didn’t understand what they were. When the renters watched the trees “die,” they called a tree service and had them removed. By the time I heard this story, it had been many years since the trees had been cut, but the anguish on the face of the storyteller was as clear as day. A very sad story indeed.

The tamarack has one of the widest and most northerly distributions of any North American conifer. Starting in Newfoundland and heading south to Massachusetts, the range of the tree then heads west to Michigan, Wisconsin and Minnesota. Then the range heads northwest through Canada before ending in Alaska.

The northern limit of the tamarack’s range appears to coincide with the northern limit of trees in general. As a result, tamarack trees have to deal with some pretty cold weather. The lowest recorded temperature that any tamaracks have survived is –79 degrees Fahrenheit. This puts tamaracks in our area in the “warm” zone. Actually, because we are near the southern limit of the tree’s range, it might be too warm.

One of the largest tamaracks ever recorded was found in Maine. The tree was about 95 feet tall and had a trunk that was about 3 feet wide. We may find trees approaching this height in people’s yards, as long as they aren’t cut down. But, trunks that wide require ages to grow.

If you’re up for a challenge, why not take a car ride through the country and see if you can’t spot yourself some larch trees? It will give you an excuse to talk with a friend or loved one while exploring the beautiful landscape that surrounds us every day. It’s there waiting for you if you will only take the time to enjoy it.

Bill Danielson has worked as a naturalist for 16 years. In that time, he has been a national park ranger, a wildlife biologist and a field researcher. He currently works as a high school chemistry and biology teacher. His Speaking of Nature column runs weekly in The Recorder, except for the first Thursday of each month, which is when his Kids and Critters column for young readers appears. To contact Bill, or to learn more about his writing, visit www.speakingofnature.com

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