Alexis is working on a lengthy series to finish off her summer term as a work-study student for BPotD, so an additional recent photograph from me today.
Another day, another thing learned. I was under the impression that there was only one taxon of subalpine fir in much of western North America, Abies lasiocarpa var. lasiocarpa (a second variety, Abies lasiocarpa var. arizonica is found at high elevations in the southwest USA; see The Silvics of North America entry for how I understood the definition of Abies lasiocarpa). Digging a little deeper, I learned that the Flora of North America recognizes Abies lasiocarpa as a species distributed from Alaska through to California and a different taxon, Abies bifolia, as a species associated with the Rocky Mountains. Where the two taxa meet, introgression occurs (i.e., gene flow between the species, leading to populations or individuals with intermediate properties). Abies lasiocarpa var. arizonica is not formally recognized in the Flora of North America, though the author makes mention that it is likely instead a variety of Abies bifolia and that further study is needed.
The Gymnosperm Database treats the diversity of this group differently, recognizing three varieties of Abies lasiocarpa instead: Abies lasiocarpa var. lasiocarpa, Abies lasiocarpa var. arizonica and Abies lasiocarpa var. bifolia. Depending on the taxonomic approach, the plant in today’s photograph would either be considered Abies lasiocarpa var. lasiocarpa (if other varieties are recognized, such as in The Silvics of North America or The Gymnosperm Database) or Abies lasiocarpa (if Abies lasiocarpa has no varieties, such as in the Flora of North America). Learning this today has prompted a re-examination of the Abies lasiocarpa in the UBC Botanical Garden collections, as we’ll now have to decide which approach to use and then update the name on the plants from wild-collected seed from the Rocky Mountains of British Columbia.
A recent study has shown that small mammals prefer the seeds of other subalpine conifers over those of subalpine fir. This has generated a hypothesis that subalpine fir may have a competitive advantage over its coniferous cohorts, as its seeds are less likely to be eaten by rodents and it may therefore have higher establishment of seedlings (see: Lobo, N. et al. 2009. Conifer seed preferences of small mammals. Can. J. Zoo. 87(9):773-780. doi:10.1139/Z09-070).