Educator • Author • Ecologist
One of the most interesting geologic stories in western North America is told by the ultramafic rocks that were formed deep in the ocean floor. As the Pacific Plate collided and dove beneath (subduction) the North American Plate, the bottom layers from deep oceanic mantle were scraped (obduction) onto the North American Plate. These depositions are referred to as ophiolites and the Klamath Mountains present some of the most extensive examples on Earth.
The 346,177 acre San Gabriel Mountains National Monument was dedicated in October 2014 by a proclamation by President Obama after nearly 10 years of work to get it established. It contains the Sheep Mountain Wilderness, the San Gabriel Wilderness, and Pleasant View Ridge Wilderness as well as most of the major peaks including Mount San Antonio, Mount Baden-Powell, and Throop Peak.
I’ve been contracted by the US Forest Service, in partnership with the California Native Plant Society, to map Bigcone Douglas-fir in the monument as well as write a technical report about our findings. We did initial reconnaissance last week and will return later this year to initiate the project’s data collection phase. What follows are images from our trip across the range to meet the species and the monument.
Because I will undoubtedly be making more posts about PSMA, as I embark further into a mapping and monitoring project in the San Gabriel Mountain National Monument, I thought a post that provides an overview of this amazing species would be in order.
It has been called the desert fir (Jepson 1920), bigcone spruce (Munz 1959), false hemlock (Sargent 1884), and ultimately bigcone Douglas-fir (Abrams 1923). Clearly there was confusion as to this species relationship to other members of Pinaceae. It is now described as a Pseudotsuga, being ecologically distinct from its taxonomically complex western North American counterpart, Douglas-fir (Pseudotsuga menziesii). In addition to bigcone in Southern California, five other species of Pseudotsuga occur across Canada, USA, Mexico, Japan and China.
I have always wanted to visit the San Dimas Experimental Forest and as part of a mapping and monitoring project for bigcone Douglas-fir, I finally had the opportunity. The “forest” descriptor in the area’s title is a bit misleading, as the majority of the vegetation is chaparral–but there are trees and it was our mission to find them (or at least what remains). Six major fires have been documented here since 1914, with the most recent occurring about 10 years ago. These fire events, along with climate change, are rapidly reshaping the remaining stands of trees. What follows is a photographic journey into the front range foothills of the eastern San Gabriel Mountains.
This was one of the most relaxing vacations I’ve had since we visited Hawai’i several years ago. There was no work to be done, no agenda to maintain–just time to swim, rest, and of course botanize and bird the Maine woods (click HERE for my bird list). I had one target plant to find in Maine–Kinnikinnick. I wanted to see a manzanita on the East Coast. This might have been the most difficult part of the vacation, being as it took me nearly 10 days to find the species! But on the second-to-last day, in Acadia National Park on the summit of Cadillac Mountain, we found it under a layer of fog. What follows are some images from the trip. Happy Plant Exploring.
