A Breath of Life

Poplar bud in springSpring is in full-swing here now. In the southern reaches of Manitoba, some trees have leafed out almost fully and many of the ornamental fruit trees are in full bloom. At home around the lake, however, things are moving just a little slower. The first blush of green is only now enveloping the forest and I find it fascinating how only a few hundred kilometers can make such a difference in to the rate of renewal after winter’s chill.

As with many natural processes, day-length does play a role, but the story here is much longer and more complicated than that. In fact, the stage for each spring’s grand entrance is set the previous fall.

The shortening autumn day signals to the tree that it’s time to enter into a period of dormancy, sort of a forced vacation, where all systems shut down to preserve the tree’s tissues and protect it from freezing temperatures and water loss. Before it enters into this stasis, the tree uses the last of its growing resources to form the buds for the following year, encasing these primordial leaves in waxy scales that hold them in place until they get the go ahead to continue development.

After everything shuts down for the winter, the process shifts into a sort of time-release mechanism. Each species has it’s own mandatory vacation period, a set number of cold days it must endure before any warming will trigger the growth of new leaves. That period, however, is usually shorter than the average Canadian winter. So if we get a sudden early warming, like we did this year in March, it can trigger the start of new leaves, which can then be a death sentence if the forest is then hit with another cold snap. Alternatively, really warm autumns or warm winters can delay the onset of budding by pushing back the point at which the ‘mandatory cold period’ started. This reliance on temperature to maintain their cycle may make it very difficult for trees to adapt to the rapid changes in climate patterns we’re starting to witness.

Here in Manitoba’s boreal, however the wave of green is sweeping across the landscape as it always has this time of year. It happens so fast, that if you’re not paying attention, you can miss the in between stages and those are the best parts.

My absolute favourite time is when the Balsam Poplar’s (Populus balsamifera) buds (pictured above) begin to swell to bursting. They’re full of sticky, volatile oils that fill the air with a warm heady scent, that’s a pleasant mix of vanilla, cut fir boughs and Vicks Vaporub. I’ll never forget my first experience with a Balsam Poplar stand in full bud. It’s an amazing smell that washes through you, leaving you both calm and invigorated all at the same time.

Balsam poplar buds in oil

Soaking up the sun – Steeping balsam poplar buds in oil, the beginnings of Balm of Gilead

The healing effect may not just be limited to your sense of well-being. For centuries, Aboriginals and European immigrants alike have used poplar buds for medicinal purposes, typically warming them in some sort of fat to draw out the oils and then using the resulting salve on everything from wounds, eczema, and rashes to lining the inside of the nose to clear up airways. I learned how to tease the benefits from the bud from a woman living in the farmlands north of Swan River, Manitoba.

After steeping the buds in a good-quality oil in the sun for several days, strain off the liquid and thicken it with beeswax. The result is known as Balm of Gilead and makes a nice skin cream that smells wonderful.¬† Beyond it’s fragrance, the oils also contain salicin, a compound similar to aspirin that has been used as an analgesic by many cultures.

Whether it’s grounded in chemistry or not,¬† I still believe there is nothing better for your health and well-being than getting out an experiencing the first breath of life that is spring in the forest and surrounding yourself in its fragrant, verdant beginnings.

One of These Things is Not Like the Other

No matter how hard we cling to the long light, crisp mornings and golden trees, fall, like all good things, must eventually come to an end. Autumn is gasping its last breaths here in the boreal forest as the cold November winds sweep away the last of the colour and hard frosts condition us for the deep freeze to come.

Our last blaze of glory before the forests fade to the dull greys and bleached greens of winter comes from an unlikely source, a tree that should be an evergreen. I’m talking about the Tamarack (Larix laricina).

Also known as larches, tamaracks are conifers, needle-bearing trees; but unlike their boreal forest brethren, they are one of the only North American evergreens that don’t remain ‘ever-green’. Tamaracks are deciduous conifers, a beautiful paradox that bring one last flash of light to the forest before it’s extinguished by the wind scattering their needles all over the ground like a Christmas tree in January.

So, why do they do it? Did larches miss the ‘conifers are evergreens’ memo?

The jury seems to still be deliberating on the evolutionary history, costs and benefits of this strategy, but when you take a step back and think about it, larches are taking advantage of the best of both worlds. Broadleaf trees, like aspen and birch, create leaves that are relatively cheap to produce, with a large surface area-to-volume ratio that makes them high-efficiency photosynthetic factories. Unfortunately, that large surface area also makes them incapable of handling wild swings in temperature and moisture. So, deciduous trees cut their losses and lose their leaves when conditions no longer favour them.

Conifers take a different approach. Their needles are built to last, their low surface area-to-volume ratio and waxy covering make them much more resistant to temperature and moisture extremes. This allows the tree to keep them all year, which is necessary, because they don’t produce nearly as much energy through photosynthesis as their deciduous counterparts.

Tamaracks straddle the fence. Their needles are soft and long, with thinner cuticles and a little more surface area. This allows them to make the most of the summer sun and produce as much food as possible through photosynthesis, while protecting them from the wild swings in temperature and moisture typical of the northern boreal forests. Having needles also makes it possible to extend their season, turning sunlight into food right through to the end of October. Then, when the frosts set in and snow is in the clouds, the photosynthetic pigments shut down, leaving the needles a brilliant gold before they flutter to the ground. Without the added strain of maintaining their needles, the tree can survive  harsh winters that can sometimes damage other conifers.

This strategy has allowed tamaracks to survive and even thrive in some pretty difficult habitats, from the edge of the Arctic treeline to the waterlogged and acidic soils of bogs.

As a field biologist, I’ve had sort of a love-hate relationship with tamarack. Whenever I spotted a stand of these trees towering in the distance along my survey line, I knew that I would soon find myself up to my knees in water and would spend the rest of the day trying to dry out my boots. Then, I would find myself in their midst, their soft, feathery limbs brushing me as I passed as though welcoming me into their world. Now, it’s a world a return to visit as often as I can.