The Miracle Mile

Four months ago I don’t even think I was aware that the Klamath Mountains existed. While the Arcata BLM field office only dips a toe into the Klamaths, I am using this blog entry to elucidate why they have been a fascination for me during my time in Northwest California. The cause for my enchantment can be summarized by one word: diversity! A popular example of the Klamaths’ biodiversity is their enriched conifer stands, where an unusual number of conifer species grow in close proximity. Specifically, the “Miracle Mile” contains 18 species within one square mile.

Occupying less than 10,000 square miles in Northwest California and Southwest Oregon, the Klamaths’ geologic diversity is what enables the rich biodiversity. The road to the Klamaths’ current manifestation began 500 million years ago, with continental fragments and volcanic island arcs in the ocean that eventually were pushed onto land, fused with other rock types, metamorphosed, and overlaid with various sediments. All of these events gave birth to their own unique rock type. And after all of that tectonic jostling, the Klamaths wound up at the crossroads between the Coast Ranges, Cascades, Sierra Nevada, Great Basin, and CA’s Central Valley. Species of all 5 bioregions can be found in the Klamaths, in addition to endemics that grow nowhere else.

Due to the heterogeneity of soil and climate microsites that the mountains provide in countless combinations, the region has been able to hold on to species that have long since been extinguished from nearby mountain ranges. A striking example of this is Darlingtonia californica, a carnivorous pitcher plant growing on serpentine soils whose closest relative is found in coastal bogs of North Carolina. And the Klamaths hold the world’s last populations (growing healthily) of Brewer’s Spruce. The Klamaths have the southernmost populations of conifers common in Alaska, and the northernmost populations of conifers growing in Mexico. Conifers grow next to each other that associate nowhere else. Because of this, species are hybridizing into new variations. And populations of certain species behave differently than anywhere on Earth, often because they grow on different soils.

I was lucky enough to hike to the Miracle Mile with Michael Kauffman, the author of Conifer Country (www.conifercountry.com), the book that introduced me to much of this information. Before the hike I could barely tell the difference between pines, spruces, and firs. How naïve I was! On the hike I learned to identify sugar, ponderosa, Jeffrey, western white, lodgepole, whitebark, and foxtail pine; white, Shasta, Douglas, and subalpine fir; Brewer and Engelmann spruce; mountain hemlock; Pacific yew; incence-cedar; and common juniper. What I imagined would be subtle differences often turned out to be glaring individual expressions. But there were still plenty of cryptic hybrids and mischievous misbehavers to confuse our group of professional and amateur botanists. Watching the birth of new species is an exciting thing!

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