Mt. Nusatsum

Mt. Nusatsum

Friday, February 19, 2010

Whitebark Pine

Whitebark pine (Pinus albicaulus) has to be one of the most special trees in British Columbia. It's also a favourite of mine to boot.  Why?   Well first thing is it's found only in the mountains, usually in the subalpine zone and around Bella Coola that means starting about the 5000' elevation and in the area east of Noosgulch Valley.  Any tree confined to just the mountains is always special (we have four conifer species around Bella Coola that are 'mountain trees').   There are a whole bunch of things which make it interesting not the least of which is that it can be extremely long lived--in the top 25 of the oldest tree species. It's form of growth is also quite striking. It rarely is a perfect 'tree' shape often mis formed by life time misadventures ranging from snow and wind damage to lighting strikes.  In the Rainbow Mountains the larger specimens are so striking from a distance in  amongst the stands of Lodgepole Pine (Pinus contorta) that your eye is drawn to them.  The multiple tops, large dominant size and slight colour difference are all clues. 
A notable unique feature of the Whitebark pine is that it is almost totally dependent on a bird for it's dispersal of seed.  The whitebark pine is a member of the 'stone pines', which are pines in Europe and North America that produce large seeds, aka "pine nuts".  While the whitebark pine seeds are not as big as some in the American mid west mountains, they do produce a nice tasty seed of just over 0.5 cm long.  The cones rarely hit the ground though, because the noisy bird Clark's Nutcracker happen to be very dependent on eating whitebark pine seeds.  So dependent are they that their beaks are adapted to breaking into the tough cones to get at the seeds and they have a special pouch under their tongue to store them and carry them away.  The important part about this habit is that they don't eat all the seeds right away, but fly away and cache them for later use where some eventually get forgotten and grow.  These caches are an important source of food for grizzly bears who spend time in the mountains as well.  It is the dispersal of the seeds by Clarke's Nutcrackers which ensures the survival of the whitebark pine, because the large heavy seed has no ability to blow away or be carried by wind very far.  Clark's Nutcrackers are characters in themselves.

There is one other unique aspect to whitebark pine, a lot more serious and threatening.  All species of white pines in North America - I think there are five, are being killed off by the white pine blister rust. This is a nasty fungus that was introduced in eastern North America and then around 1919 in Vancouver.  It has spread across the entire continent and is affecting populations at varying rates.  Whole books and papers are written on the blister rust as well, but suffice to say it needs species of  currants, and gooseberries (Ribes sp.) for part of it's lifeclyle.  So there are not many areas without currant and gooseberry populations.   The whitebark pine populations in the Rainbow Mountains so far are not heavily infested by blister rust, as it is almost always fatal.  

Whitebark pine is such an interesting tree, that there is a even a foundation called the Whitebark pine Ecosystem Foundation with a web site and all kinds of interesting information dedicated to understanding and maintaining the future of this species of tree.

Our local whitebark pines have had two greater problems recently, one the mountain pine beetle and the other forest fires.  We lost a lot of the easily visible whitebark pines along Highway 20 near the top of Heckman Pass last summer during the Heckman Pass wildfire unfortunately.  There are still some great examples around, you just have to get away from the fire. Mountain pine beetles are also taking their share in some areas of heavy beetle attack as well.  Grizzly

3 comments:

  1. Thank you! I try to keep it interesting. Grizzly

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  2. Hi.

    Has the pine beetle Do the lake and streams create barriers for the beetle to spread?

    Thanks agian!

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    Replies
    1. No the lakes and streams are no barrier. They fly and the warm winds can carry them a long ways. Grizzly

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