Abies lasiocarpa

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).

Abies lasiocarpa

9 responses to “Abies lasiocarpa”

  1. Norm Jensen

    Very interesting, thanks, Daniel. But the term introgression, or gene flow between species, leading to populations or individuals with intermediate properties, sounds like what I call hybridization. I assume there are some differences in meaning. Can you explain it further?

  2. Trisha in Texas

    Introgression is (one of) a process of hybridization. Hybridization is a process name for the group of methods that could be used to cross genetics of different organisms. I love new words. New to me anyway.

  3. Renee Galeano-Popp

    Good post! 1) Based on field observations, I have always felt that corkbark fir (var. arizonica) is an environmental variant more than a genetic one but I’m not a taxonomist. 2) When it comes to conifer success, the pines are king!

  4. Piotr Krasinski (Warsaw, Poland

    Thanks for this Daniel and Alexis, however how do they differ to an amateur’s naked eye?

  5. Iris Lefleur

    Shall we submit a sap sample for DNA? How often does introgression happen in the botanical world? Fascinating……

  6. William Parker

    Interested readers may obtain more information on this topic in Can. J. Bot. 69: 1491-1500.

  7. Bill Barnes

    Given the very large geographic range of Abies lasiocarpa it seems plausible that speciation could occur resulting in an Abies biflora . Much of speciation occurs due to either genetic /physiological barrier or by physical barriers such as large bodies of water or mountians , gorges , etc. Sometimes the distances involved do not have to be very large and subtle but distinctive differences can arise and become very entrenched in the newer form. Given time those differeces can lead to intercrossing prohibitions. There is much we don’t know. Opuntia humifusa on the east coast of the US is a good example of variation leading to speciation,.

  8. elizabeth a airhart

    how long do you all think it will take to rename all the trees and
    plants then put them in another family hopefully correctly this time
    how will hurricane irene moveing up the east coast of the usa
    affect the plant life and trees ?

  9. Walt Bubelis

    I’ve observed that seedling-grown nursery stock from the compact version (Abies lasiocarpa var. arizonica ‘Compacta’) of Corkbark Fir maintain their southern distribution characteristics: i.e. glaucous foliage, compact habit, and rough, corky bark regardless of local environment (assuming enough sun). That would argue for genetic differentiation, would it not?

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