The trees of Dog Mountain

By Sancho McCann · , edited:

The Dog Mountain hike is a 4.4-kilo­me­tre hike that is ac­ces­si­ble from the park­ing lot of Mount Seymour Ski Resort. It’s rel­a­tive­ly flat, con­tained al­most en­tire­ly be­tween 1,000 and 1,050 me­tres.

We still need­ed snow­shoes when we went on this hike in March.

I am used to Douglas firs (Pseudotsuga men­ziesii), west­ern hem­locks (Tsuga het­ero­phyl­la), and west­ern red cedars (Thuja pli­ca­ta) from my hikes on low­er-el­e­va­tion trails that start near Deep Cove or Lynn Valley, but none of those trees (ex­cept a few west­ern hem­locks) were up at this el­e­va­tion. Here, there were am­a­bilis firs (Abies am­a­bilis), moun­tain hem­locks (Tsuga merten­siana), and yel­low cedars (Chamaecyparis nootkat­en­sis).

I didn’t get any pho­tos of yel­low cedar, but here are some pho­tos of the oth­ers and some cues for iden­ti­fy­ing them.

Amabilis fir (Abies am­a­bilis)

This tree is also called Pacific sil­ver fir.

The un­der­side of the am­a­bilis fir’s nee­dles are bright white due to blooms of epi­cu­tic­u­lar wax sur­round­ing the stom­a­ta and their tips are notched. The up­per sur­face (not shown here) is a deep green. On many of the branch­lets, there are two lay­ers of nee­dles: a bot­tom lay­er with nee­dles splayed out to the sides, and a top lay­er with nee­dles more aligned with the branch it­self.
Here you can see the marked difference be­tween the deep green up­per sur­faces and the sil­very un­der­sides of the am­a­bilis fir’s nee­dles. And, you can see the two lay­ers of nee­dles: one splayed out and one an­gled for­ward.

Mountain hemlock (Tsuga merten­siana)

The nee­dles of the moun­tain hem­lock are denser—more bushy. In con­trast to the west­ern hem­lock, they are not splayed out into a flat plane. The up­per and low­er sur­faces of the nee­dles are the same col­or; this tree’s stom­a­ta are spread fair­ly uni­form­ly on both sides of the nee­dle and they don’t have as dis­tinct a wax bloom.

Western hemlock (Tsuga het­ero­phyl­la)

There were only a few of these up here. You can tell this apart from moun­tain hem­lock by look­ing at the nee­dles or the cones.

The up­per sur­face of the west­ern hem­lock’s nee­dles are a smooth, deep green. They are flat, and lay along each side of the branch in a sin­gle plane, but can also be more dis­or­ga­nized.

The un­der­side of the nee­dles have two bright lines of stom­a­ta.

The west­ern hem­lock’s cones are small (about 2 cm) com­pared to the moun­tain hem­lock’s cones (3-8 cm).
One ap­par­ent­ly dis­tinc­tive fea­ture of the west­ern hem­lock is its dropped-over top (the leader), but I’ve nev­er been able to use that cue to re­li­ably iden­ti­fy this species.

Reading

Jim Pojar & Andy MacKinnon, Plants of Coastal British Columbia (BC Ministry of Forests and Lone Pine Publishing, 1994).

National Audubon Society Field Guide to North American Trees: Western Region (National Audubon Society, 1980).

The first (Pojar) has a very nar­row scope and tells much more about a species’s significance to the re­gion’s ecol­o­gy and peo­ple, both to­day and his­tor­i­cal­ly. The sec­ond (Audubon Society) is much broad­er but helps you to see what things real­ly make a species dis­tinc­tive, not just dis­tinc­tive with­in a re­gion. Both are well-writ­ten. Thomas and Turner ac­tu­al­ly point to the Audubon field guides as ex­am­ples of clas­sic style: “La Rochefoucauld, Thomas Jefferson, A. J. Liebling, and the au­thors of the Audubon Guide to North American Birds are all dis­tinct and well-formed in­di­vid­u­als, but they are all pro­to­typ­i­cal clas­sic styl­ists.”