The low-lying fog that has been smothering the valley floor this past week has called for a migration to higher elevations to lift spirits and find vitamin D. Vitamin D is essential but difficult to come by in the winter as most of our vitamin D comes from sunlight hitting our skin. Vitamin D is needed to absorb calcium to build bones, and while fortified milk and juices often have vitamin D, most people in northern latitudes need to supplement with vitamins to get the necessary amount. Vitamin D also regulates hormones and moods and lack of it can be the culprit of the winter blues.
Last winter, I invested in a full-spectrum therapy light that sits on my desk and shines non-UV light as I sit at my computer. Because the light doesn’t emit UVB light, it doesn’t help with vitamin D production, so I still seek sun light at higher elevations and take a daily dose. The therapy light does, however, make me feel more awake through the day and I sleep better at night, helping to avoid moodiness.
Now, I am not a long-timer in the valley but it feels like these foggy episodes are lasting longer than they used to. Indeed, when temperatures hover around the low 30s the fog seems to set in, often trapped under warmer, clear skies above in an inversion. The webcams at the Loup Loup Ski Bowl and Sun Mountain have become a daily ritual to find fog-free skies.
Saturday, the Sun Mountain webcam showed clear skiers and Nordic skiers packed the Chickadee trailhead. The recent 2021 Cedar Creek Fire traveled through much of the terrain home to the trails around Sun Mountain, including back burns to halt the fire spread towards Twisp. I was curious as to how the fires changed the skiing experience along the trails and headed out on the trail with friend of mine who is a wildlife biologist. One observation became an obsession as we traveled along the Meadowlark Trail: the presence and vibrant persistence of lichen on burned branches.
The presence of clumpy, bright patches seemed contrary to the obvious, that lichen typically acts as fine-textured fuel for fire. Lichen often increases fire spread up the crown of the tree fueling fire intensity. In fact, wilderness survivalists will say to use lichen as fire starter. Also of curiosity, is that lichen is slow-growing. In no way could the organism have rebounded after the fire.
Yet, along Meadowlark Trail, on tree after tree, charred black, needles deadened orange by the heat and flame, the branches held colonies of bright green branches that were loaded with wolf lichen. We kept asking ourselves, as science seekers do, how can this be?
One tree in particular perplexed us. It was completely torched, the crown had burned in full, and it had already lost its needles, yet the branches were loaded with lichen. How does this happen?
To answer the questions, I reached out to Peter Neitlich, a local research biologist for the National Park Service who specializes in lichens. He too was perplexed by this observation, leading to an explanation that perhaps the flame lengths were short enough having burned at night as a back burn when relative humidity was high enough to dampen the burn. Maybe the flames didn’t reach around the top of the branches, maybe the mat of moss and lichen on the branches held enough moisture to withstand the flame. Still, it remains one of nature’s mysteries. What do you lichen is the answer?