Dad and I drive over Snoqualmie Pass to the eastern flank of the Cascades. At home, the morning was still sleepy, covered in a blanket of low-laying clouds. As soon as we crossed over the pass, we saw the abrupt edge of the blanket, and were suddenly under an expansive blue sky and bold, late-morning sun. Welcome to the rainshadow! We both let out a little whoop at this unfamiliar landscape with its many pines and bone-dry, weightless air. A creature of a perpetually damp, maritime climate, I felt like a baby dragonfly greeting the sun, ready to air out new, crinkled wings.
The trail takes us along Cooper River, towards Pete Lake. We hike in mostly silence at first. I empty my mind of chatter, and focus on opening my senses to this landscape, becoming acquainted with the feel of it, the colors, sounds, smells, topography. The song of a Swainson’s thrush, an ascending series of pure, melodic notes, cuts through the air. If this forest has a spirit, that is it’s voice, I think.
The forest is primarily pines - more types than I can identify - as well as Douglas-fir, and the occasional yellow cedar. A few of the Douglas-firs are well over my wingspan in diameter, with bark so deeply furrowed, I could almost step right into one of the creases. Dad speculates that they have been here for hundreds of years, probably before Europeans arrived. These living giants demand, in the most gentle, humble way, reverence. Were I a thrush in this forest, I, too, would sing!
But I find myself especially enchanted by the many towering snags, and have to stop every few paces to look closely at the naked, grey wood and try to follow the trunk with my eyes, all the way to the place where it points a sharp finger toward the sky. Back on the west side of the Cascades, wood rots almost instantly; dead trees become earth, not skeletons. (I’ve frequently tried to sit on a comfortable-looking fallen log, only to discover that the inside is soft and crumbly, and fall myself, right through to the forest floor.) But here, dead giants speak of different conditions, holding memory in a different way. How?
This question brought me to the Carboniferous Period, 359.2 million years ago to about 299 million years ago. The Carboniferous Period got its name from the vast amounts of carbon stored in trees that were buried in swaths of swampy forests, becoming coal deposits that have fueled industrialization over the last several hundred years. As plants first made their way to land, woody vegetation evolved lignin - a bark fiber that provides structural stability to vascular plants, helps them transport nutrients, and protects against external chemical and biological forces. Lignin is tough (and our stomachs know it - we eat mushrooms that feed off wood, but cannot digest the wood itself). For a long stretch of time, existing organisms did not have the capacity to break down this protective layer, and trees - even the no longer “living” ones - decayed much more slowly than they do today. Imagine, vast forests where even the oldest fallen trees are still good for sitting upon!
Enter: Agaricomycetes. Through multiple evolutionary pathways, some white rot fungi in this large class of mushrooms became host to enzymes that break down the new lignin layer and can access carbon stored within. The emergence of these enzymes coincides with the slowing of coal-formation, marking the end of the Carboniferous Period. As Chris T. Hittinger writes, “Fungal rots that decay wood were not prominent among the ‘endless forms most beautiful’ that Darwin chronicled, but if he had known of the biochemical and evolutionary processes at work, they might have been.”
I would not have thought to name fungi as one of the primary characters in my experience of my home landscape. But it seems as though much of what is familiar to me about the western side of the Cascades - namely, rapidly rotting wood and the diverse ecological relationships in which it plays a vital role - has roots in the emergence of particular variations of peroxidases (PODs), the enzymes that make this possible.
Is white rot less prevalent in the drier climate of the East Cascades? What other hidden forces grant these giants their upright tenure? How does woodpecker know this, and bark beetle, and beaver, and worm? A few observations give rise to many more answers than questions, but that is precisely where the value lies. And future observations are richer for it. I took this hike to escape the city’s grid, but am also ultimately brought back to it; as inert as it appears to my senses, what cycles might asphalt by embedded in, what niches has it created, what evolutionary opportunities might it afford?
Information is physical. A hemlock in Puget Sound bears information in its own particular way, information which cycles through an ecosystem in diverse forms - perhaps as young shoot, leaf mould, worm casting, robin scat, soil, and back again to young shoot, with many meandering pathways between. An east-side pine cycles, too, but differently, and with a structural integrity that persists longer - thanks at least in part to lignin and the relative absence of saprophytic fungi. Matter organizes itself in different ways; each iteration an embodiment not of isolated bits of information, but of cycles, of stories, of relationships. This, I think, is where my mind is most alive - in the places where I can experience directly “endless forms most beautiful,” the rotting hemlock and the standing Douglas-fir.
I hike with Dad to Pete Lake and jump into the water, which is so cold it makes my toes ache. I’m grateful for it, though, in this dry place. We sit on a boulder - a glacial erratic left here over 10,000 years ago, says my geology-enthusiast father - and eat lunch while a lone duck glides by, dipping its beak in the water. As we follow the same gentle trail back to the car, I wonder where my memory of our hike will live, when I am walking again upon concrete streets - within me, to be sure, but perhaps primarily right here in this forest, solid and irretrievable. We catch a glimpse of a baby Swainson Thrush, babbling early hints of its song, on our way back.