Replant.ca Environmental

Replant.ca Environmental is a Canadian organization whose vision is to help our global environment through planting trees. We build demonstration forests that are accessible to the public. We also plant in public parks, and we build carbon capture plantations that help mitigate climate change. Our operations are funded by NGO's, corporations, and numerous small donations from global citizens who know that their individual actions will help make a difference.

Sunday, October 25, 2020

The White Birch Tree (Betula papyrifera)

Last week we looked at the yellow birch. This week, we'll look at another birch tree which is more well-known: the paper birch. Unlike the yellow birch, the paper birch grows well almost everywhere in Canada, and due to its white bark, it is something of an iconic tree. The white bark is obviously the reason why this species is perhaps more commonly referred to as white birch. In some areas, it is also called "canoe birch."

Let's start with a photo of a semi-mature tree, so we can get a good look at the bark. If you go back to our yellow birch post, you'll see that the colour difference is fairly obvious on your computer screen, but you may not find this to be the case in the field. Sometimes, a yellow birch will appear to be a lot more pale in colour, or a "white" birch might appear slightly creamy-coloured, which can really confuse observers. A better way to improve your identification skills is to look carefully at the composition of the bark, and the way that it flakes or peels off the trunk. Strips of paper birch bark are generally thicker than that of yellow birch bark. Even more telling is the outward appearance. While the yellow birch flakes in many small curls, paper birch usually peels off in much larger sections. In some instances, on mature trees, you might almost be able to peel off a piece that is about the size of a piece of photocopy paper. There is almost universal agreement that the paper birch is a very "pretty" tree.

Despite the very white bark on mature and semi-mature trees, the bark of juvenile paper birch trees is actually quite red! This is the case from the time that the tree is just a germinant or whip until the diameter of the truck is thicker than an inch or two. Here's a photo. Take a close look at the tiny white marks all over the red bark, which help clarify that these trees are paper birch:

Unfortunately, the paper birch is not as healthy as the yellow birch. A mature paper birch may only live about half as long as a yellow birch, as most only survive for about a hundred years. Incidentally, paper birch trees that live in colder climates tend to live longer than specimens in the southern part of their range. On a positive note, a single birch tree can release more than a MILLION tiny seeds (samara) in a season, so one mature tree can help generate a huge number of eventual successors.

Paper birch supposedly grows to be slightly smaller than yellow birch at maturity, but we've found that the two species are quite similar. We have a number of mature birch of both species on some of the properties that we manage, and many of the paper birch trees are around twenty meters (seventy feet) high, with a DBH (diameter at breast height) of about 60 cm (two feet). This is similar to the size of mature yellow birch in this region.

Here's a range map of the paper birch, courtesy of Wikipedia:

Fun fact: The paper birch is the provincial tree of Saskatchewan. It's also the state tree of New Hampshire.

Let's get back to examining the paper birch in more detail. Have you ever walked through the woods and found a rotten piece of paper birch on the ground, and discovered that while the bark is still intact, the wood inside has completely rotted away? This happens fairly often. This is because the bark of the paper birch has a very high oil content, and is very waterproof. This helps ensure that it is more resistant to rot than the wood in the core of the tree.

Paper birch trees are "monoecious." This means that an individual tree has both male and female flowers, called catkins. The catkins tend to develop in May or June. Female catkins are greenish, and are smaller than the brownish male catkins. By early fall, the seeds have matured and begin to fall. Seeds continue to fall throughout the winter. Most people wouldn't be able to describe a birch seed when asked, because they are fairly tiny and not at all obvious to someone taking a walk through the woods. However, next time that you're walking through a stand of birch trees with snow on the ground, take a close look at see if you see a lot of small brown specs on the surface of the snow. These may be birch seeds!

To see a good illustration showing how small birch seeds are, check out this short YouTube video from someone who is demonstrating how to grow silver birch:

https://www.youtube.com/watch?v=4zcyYRqe9-g

Ok, it's time for some more fun facts about paper birch!

1. If you're planting both paper birch and black walnut on the same property, don't plant them close to each other! The roots of the black walnut secrete a chemical (juglone) which is very toxic to paper birch trees.

2. Although paper birch bark is a staple food for moose, it is full of lignin which is hard to digest. For this reason, moose need to eat many other types of plants in combination with the birch. Incidentally, deer also love to eat the bark of the paper birch, especially once the snow cover gets deep and ground forage is hard to get to.

3. The leaves of the paper birch often appear in pairs. They have toothed edges which are called margins.

Birch trees are an important part of the mix of hardwoods that we plant on the properties that we manage. We have to think about carbon sequestration and longevity, so we tend to plant a greater number of yellow birch than paper birch. However, paper birch are very attractive so it would be a failure not to include them. As a forest reaches a steady state maturity, with old trees being gradually replaced by young trees, a mix of yellow and white birch is beneficial. Having said that, paper birch is more of a pioneer species than yellow birch, which means that it thrives better than yellow birch in openly disturbed forests with lots of exposure to sunlight. In the long term, we feel that yellow birch (a shade-tolerant successional species) has a bit of an advantage over paper birch for a mature forest with lots of shade. Here's a photo of some of our white birch seedlings:

Thanks for reading ...

- Jonathan Clark
www.replant-environmental.ca

Replant.ca Environmental is a Canadian company that plants trees for carbon capture and builds community forests. We also plant trees in national, provincial, and municipal public parks to mitigate damage from wildfires, storms, insects, and forest diseases. We operate thanks to numerous small contributions from the general public, in addition to larger project sponsorships from businesses and corporations around the world. If you'd like to learn how to show your support, visit our donations page. Even if you aren't able to make a contribution, we very much appreciate when people are able to share our posts or our website link on social media, to help spread the word about the work that we're doing!

Teachers are welcome to use content from this post for their classes. If you know a teacher who might like to use this information, please share it with them! The more that people learn about trees, the better our world will be.

To learn more about the various species that we plant, visit the conifers page or the deciduous (hardwoods) page on our website. Thanks so much for your interest!

Incidentally, our organization is often seeking additional land for our carbon capture projects. Please visit this link if you might know of a recently-harvested property that we could rebuild into a permanent legacy forest.

Thursday, October 22, 2020

The Yellow Birch tree (Betula alleghaniensis)

The Yellow Birch tree is also known in many areas as Golden Birch. Our Quebecois readers will certainly be quite familiar with this species, as it is the provincial tree of Quebec. In that province, it is sometimes referred to as the merisier.

The yellow birch tree has long been sought as an important tree in North America's lumber industry. Traditionally, its wood has been used for everything from flooring and furniture and veneer to doors, cabinets, and even toothpicks. If you go to a lumber store and buy birch, chances are high that it is yellow birch that you're getting. The wood of the yellow birch can be polished quite well, and also looks good when stain is applied. The colour of the wood is not consistent though. It can sometimes be quite white, but some trees tend to be very dark yellowish. The name though comes from the golden yellowish colour of the bark as the tree starts to mature. For the kings and queens of old, gold symbolized the crown. That seems appropriate, since the yellow birch is the most regal of the birches.

Within Canada, yellow birch is only found naturally in the eastern half of the country. It's a very common hardwood in Quebec and the Maritime provinces, and down through the eastern seaboard of the US. Here's a range map, courtesy of Wikipedia:

Although yellow birch is not known for being a tree that likes to live in swamps, I've found in the past that I tend to discover more yellow birch in wetter areas and slopes than in flat open areas, whereas I see more paper birch in those drier areas.

Yellow birch will eventually grow to be the largest birch species in North America. They can grow to be more than 25m tall (80 feet) and almost a meter (three feet) in diameter, although mature trees are more likely to be a bit narrower than that. Yellow birch trees can live to be more than two hundred years old if left undisturbed.

The seeds of the yellow birch are interesting. The tree produces significant amounts of seed some years, and minor amounts in other years. The yellow birch has catkins which are the tree's flowers. Each tree is "monoecious" which means that it produces both male and female flowers on the same tree. The male catkins hang down from the ends of branches, and are usually a couple inches long. The female catkins are only half this size, and grow upright beside the leaves. When the tiny seeds are released in the autumn, they don't tend to establish when they sit on top of a layer of leaf litter. However, if they land in an area with more moisture, they are more likely to germinate (especially in moss or in cracks of logs and rocks). Yellow birch also grows from seed quite easily in nurseries.

Yellow birch can be distinguished from paper birch fairly easily by looking at the bark. In addition to differences in the colour, the yellow birch peels off in very fine, small, curly strips compared to paper birch. Many of these peelings are less than a centimeter wide.

Historically, the yellow birch had many uses beyond lumber. In addition to being used to make tea, yellow birch can be used to make a syrup, much like maple syrup. Although it is usually quite a bit more expensive than the more traditional maple syrup, you should be able to find it in a lot of Canadian grocery stores. You can find books on Amazon that describe the science of tapping and distilling birch syrup, although this information is usually included as side notes in books about making maple syrup. Birch syrup needs to be distilled more, thus a smaller volume of the end product is produced than from the same volume of maple sap.

Birch syrup and maple syrup have very different tastes to them. This isn't surprising when you dig deeper. Maple syrup is mostly composed of sucrose, whereas the sugars in birch syrup are mostly fructose with a bit of glucose. Birch syrup is much darker and stronger than maple syrup, and arguably quite a bit healthier for you. Some people compare the taste of birch syrup with that of molasses, depending on how it is made. Due to this, many people prefer the taste of maple syrup. For some, birch syrup is an acquired taste. There's a good article about birch syrup at this link:

https://smallfarms.cornell.edu/2015/04/weighing-the-pros/

Aside from its use as a hardwood for lumber, for firewood, or for the production of birch syrup, here are a few fun facts about the yellow birch:

1. A decoction of birch (boiling out a liqueur from the plant) can be used as a sleep aid.

2. When turned into an essential oil, yellow birch is often used as an anti-inflammatory to relieve joint or muscle pain (applied externally), and is also used as a massage oil.

3. Yellow birch is used as a source of "Oil of Wintergreen" which is used as a flavoring and/or active ingredient in various medicines.

At Replant.ca Environmental, we include yellow birch trees in some of our species mixes in eastern Canada. We typically source them from the Scott & Stewart forest nursery in Nova Scotia. The yellow birch is a fast growing hardwood, and as you'll have learned by now, it's a great species to include in our Canadian forests. Here is a photo of some of our yellow birch seedlings: