The Black Spruce tree (Picea mariana)

Today's post is about a species which rarely gets any love.  It's the swamp-loving black spruce (Latin name Picea mariana).  Here's a typical photo, which I took from a helicopter in northern Alberta (the majority of these trees are black spruce):

Oddly enough, the black spruce doesn't have any other common names (except in French), regardless of where you find it across Canada.  And you WILL find black spruce all across Canada.  Its geographic range is much more diverse than even the Jack pine.  Black spruce can be found in all ten provinces and all three Arctic territories.  Here's a range map, courtesy of Wikipedia:

It's quite easy to find specimens of black spruce.  Just look for a swamp.  Black spruce thrives in wet areas, even when the water is quite stagnant.  Remember that all spruce trees love water, but most varieties prefer flowing, oxygenated water.

Black spruce has roots that are especially shallow and wide-spreading.  This allows it to thrive in areas which are too wet for competing species.  Trees, like many other creatures, can drown.  Shallow roots help ensure that the black spruce does well in swamps.  Trees need water, but they also need oxygen.  Flood their root systems, and they will eventually die.  Some trees can only tolerate root submersion for as little a week or so before they start to die.  The black spruce can survive for more than a month.  Regardless, their shallow roots make it less likely that they won't have any access to oxygen for extended periods.  Unfortunately, it also makes this species susceptible to blowdown in windstorms.

If you take a close look at black spruce trees near bogs and swamps, you'll see that the closer you get to water, the less vigorous the growth.

Spruce trees rarely grow to be large trees.  It is quite common for mature black spruce trees to be no more than 15m in height, although they can occasionally grow to 25m in really good conditions.  However, you're more likely to see them in the 10m to 15m range.  The trunk rarely grows to more than 50cm in diameter (a foot and a half) for a large tree.  On a positive note, black spruce usually have very straight trunks, without a significant taper until the very top of the tree.

The top of the black spruce is interesting.  The crown is narrow and pointed, and the small branches all droop, yet the tips are turned upward.  Unlike the tips, the cones hang downward.  Here's an excellent photo from Wikimedia Commons:

One of the more interesting things that many people learn about the black spruce is their long-term fire ecology behaviour.  Black spruce trees often live in peat bogs, as well as swamps.  Despite the moist ground, black spruce stands are especially susceptible to wildfires.  If you're puzzled about this, it's important to know that monocultures (especially conifers) are often especially susceptible to wildfires, while mixed-wood forests with lots of species such as aspen will be less susceptible.  Since black spruce is so much more tolerant of swampy/boggy conditions than most other trees (except for larch/tamarack), it tends to grow frequently in pure stands.  These pure stands are susceptible to fire, despite the wet ground.

Black spruce stands tend to burn frequently, but they also regenerate quickly immediately after a fire (just like lodgepole pine).  Therefore, a lot of black spruce stands tend to be very even-aged.  Over time (centuries), swampy areas with black spruce will often slowly become filled in by organics, and the surface of the ground will become elevated and drier.  As this happens, there will be ingress from moderately moisture-tolerant species such as tamarack, white cedar, white spruce, balsam fir, and eventually balsam poplar and trembling aspen.  Don't judge black spruce as an ugly swamp tree with no significant value.  In the long term, it's an important precursor to more diverse mature mixed-wood forests.


I'll leave you with three random facts about the black spruce:
- This is the provincial tree of Newfoundland and Labrador.
- Like red spruce, it is good for making spruce beer.
- Disposable chopsticks are often made of black spruce (or trembling aspen).

That's all for now.  I hope you enjoyed reading this, and it made you appreciate this species a bit more.  We don't plant very much black spruce at Replant.ca Environmental, simply because it's not great for long-term carbon capture, but it does occupy a small percentage of our annual seedling mixes due to its suitability (along with cedar and tamarack) in swampy ground.  Here's a photo of some of our black spruce 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.