As a rule, the severity of the winter becomes harsher with an increase in altitude. In the lowlands, around the periphery of the Park, conditions are more favorable for life, as these valley settings are capable of supporting a wide diversity of flora and fauna. However, closer to the summit of the peaks, the weather becomes as inhospitable as at much higher latitudes, such as near the Arctic Circle, where only a handful of extremely hardy forms of vegetation can flourish to grace the rugged, boulder strewn terrain. Among the woody plants that are successful in rooting in the shallow soil of these frigid, wind swept sites is the balsam fir (Abies balsamea), known as our most popular type of Christmas tree.
The bitter cold atmosphere that prevails at these locations is incapable of holding much moisture, resulting in extremely low humidity. As this ultra-dry air buffets the needles, twigs, and trunk of the balsam, along with the few other species of trees that grow in this zone, it attempts to draw out whatever water molecules are present in exposed tissues.
Similarly, under the crystal clear skies of the long days of early summer, the intensity of the sun at these higher elevations would quickly bake moisture out of surface cells if they were not somehow sealed. It is intense dryness, rather than exposure to low temperatures, that creates a challenge for the various plants that attempt to gain a foothold there.
The resin that gives balsam its characteristic fragrance is fundamental to the fir’s success, as this gooey sap is highly effective in sealing moisture in and preventing desiccation. Even though the soil may often be saturated with water from frequent periods of rain, and prolonged exposure to water laden clouds that may shroud the slopes for days, once the ground freezes in late autumn, the resulting ice crystals can not be taken in by the roots and transported throughout the tree.
Consequently, it is quite common for plants of this zone to be without access to outside water from mid November through April. Any water that is in a plant at the start of the winter must be held there for the next 5 months, or it could suffer debilitating dehydration, or death.
Because of balsam’s drought tolerance, its needles are far less likely to drop off its twigs after the tree has been cut. When placed in a stand containing water, a balsam fir will remain relatively fresh for several weeks. This is considerably longer than other conifers, as some react to the dry inside air by shedding their needles within a week after being propped-up in a living room corner.
Periodic snowfalls and bouts of rime icing that encapsulate the surfaces of everything at upper elevations not only create a picturesque appearance to the terrain, but also are effective at assisting the plants of this region to deal with the issue of dryness. Being encrusted in a layer of dense snow or ice, the needles and twigs are no longer exposed to the evaporating effect of the air, regardless of how strong the winds may become.
Even though the weight of the snow or ice on the branches occasionally becomes substantial, the limbs of fir are adapted to bend, rather than snap. Despite being entombed in ice for well over a month, the branches spring back to normal once the weight falls off, or melts. This ability of balsam branches to support a fair amount of weight allows people obsessed with hanging hundreds of ornaments to completely cover its boughs with all-types of seasonal decorations and not have the branches break.
Aside from making a great Christmas tree, balsam fir contributes greatly to the wildlife community of those areas in which it grows. The ecological role of balsam was best presented by Ellen Rathbone’s article on balsam fir which appeared in the Almanack almost exactly two years ago.
Please remember that while balsam makes a great Christmas tree, it is one of our most flammable trees, especially after it has been indoors for a few weeks. Caution should always be used to ensure that it is a safe distance from heaters, wood stoves and candles; and when its needles start to fall off, it is time to put it outside.
Have a great Christmas and enjoy your Christmas tree, even if it isn’t a balsam.