trees-of-dog-mountain.html.pm

#lang pollen

◊define-meta[page-title]{The trees of Dog Mountain}
◊define-meta[original-date]{2018-05-26}
◊define-meta[edited-date]{2018-07-24}

The ◊a[#:href
"https://www.vancouvertrails.com/trails/dog-mountain/"]{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.

◊img[#:src "assets/dog_mountain_trail.jpg"]

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

◊img[#:src "assets/dog_mountain_scenery.jpg"]

I am used to Douglas firs (◊em{Pseudotsuga menziesii}), western
hemlocks (◊em{Tsuga heterophylla}), and western red cedars (◊em{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
(◊em{Abies amabilis}), mountain hemlocks (◊em{Tsuga mertensiana}), and
yellow cedars (◊em{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.

◊heading{Amabilis fir (◊em{Abies amabilis})}

This tree is also called Pacific silver fir.

◊fig[#:src "assets/amabilis_fir_underside.jpg" #:width "450px"]{The
underside of the amabilis fir's needles are bright white due to blooms
of ◊a[#:href
"https://en.wikipedia.org/wiki/Epicuticular_wax"]{epicuticular wax}
surrounding the ◊a[#:href
"https://en.wikipedia.org/wiki/Stoma"]{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.}

◊video-player[#:src "assets/amabilis_fir.mp4" #:width "450px"]{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.}

◊heading{Mountain hemlock (◊em{Tsuga mertensiana})}

◊fig[#:src "assets/mountain_hemlock_needles.jpg" #:width "450px"]{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.}

◊heading{Western hemlock (◊em{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.

◊fig[#:src "assets/western_hemlock_topside.jpg" #:width "450px"]{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.}

◊fig[#:src "assets/western_hemlock_underside.jpg" #:width "450px"]{The
underside of the needles have two bright lines of stomata.}

◊fig[#:src "assets/western_hemlock_cone.jpg" #:width "450px"]{The
western hemlock's cones are small (about 2◊nbsp[]cm) compared to the
mountain hemlock's cones (3-8◊nbsp[]cm).}

◊video-player[#:src "assets/western_hemlock.mp4" #:width "450px"]{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.}

◊heading{Reading}

◊format-work[#:type "book" #:author-given "Jim" #:author-family
"Pojar" #:author2-given "Andy" #:author2-family "MacKinnon" #:title
"Plants of Coastal British Columbia" #:publisher "BC Ministry of
Forests and Lone Pine Publishing" #:year "1994"]

◊format-work[#:type "book" #:title "National Audubon Society Field
Guide to North American Trees: Western Region" #:publisher "National
Audubon Society" #:year "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. ◊a[#:href
"http://classicprose.com/csguide.html"]{Thomas and Turner} actually
point to the Audubon field guides as examples of classic style: ◊em{"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."}