Pinecrest Creek is piped underground from just south of Carling Avenue to near its mouth at the Ottawa River. Above, Erik looks for invertebrates.

by Bev McBride (photos: Bev McBride)

Today’s [Saturday, November 2, 2019] OFNC field trip, “Transit explorer series, Lincoln Fields the other way,” was fun and interesting. I can say that, even though I was the leader, because the small group of participants made it so.  Many thanks to Bei, Erik, and Mike. It was well worth it to explore pathways to the south of Lincoln Fields transitway station. Last time we went north toward the Britannia Conservation Area and the Ottawa River.

Following the Pinecrest Creek bike path southbound out of the transitway station, you soon pass under Carling Avenue. Before long you’re away from the really noisy traffic. Even the transitway buses are just a dull hum in the distance.

Pinecrest Creek is piped underground from just south of Carling Avenue to near its mouth at the Ottawa River. If you look at aerial imagery. such as with Google Earth, you can see its small delta just to the east of the Britannia Conservation Area woods. Once you’ve gone upstream and passed under Carling Avenue, you can see on your left the opening where the creek plunges underground. Southbound from there, towards Baseline Rd., the river is above ground for some distance.

Pinecrest Creek “delta” in Ottawa River just east of Britannia woods. Source: Google maps

Opening where the creek plunges underground. Source: Google maps

As is usually the case on naturalists’ walks, it took us several hours to cover only a short stretch. We examined the riparian vegetation and noted some vegetation control activities aimed, it seemed, at the invasive species Himalayan Balsam (Impatiens glandulifera). You might have seen this plant around. It looks like a giant, purple-flowered version of the common, widely-distributed, native species Spotted Jewelweed (Impatiens capensis).

As an aside, I wondered what capensis meant in this case, because I was sure I’d seen it used as the species names of plants originating from the Cape of Good Hope at the southern tip of Africa.  Impatiens capensis Meerburgh is the name including the author citation. Nicolaas Meerburgh, the curator of the Leiden Botanical Garden in The Netherlands from 1774 to 1814, first described and classified this species. He would have been working from collected specimens and apparently he somehow mistakenly believed that the plant had come from the cape of Africa. See
Impatiens capensis Meerburgh, for example.

Pinecrest Creek’s banks offer a glimpse of local geology

I enjoyed looking at the creek’s channel. It has carved, steep banks in some places and exposed bedrock in others. Along at least one stretch, the grey clay formation underlying the topsoil was exposed. There are some riffles and small rapids.

After the recent rain, the flow was likely relatively high for the time of year. The water seemed clear. An interpretive panel that we found near the end of our hike told us that urban storm draining is a big source of the creek’s water (see below).

In some places it was very easy to walk right down to the creek. We looked for invertebrates on the stones in the stream and found some unidentified isopods, a caddisfly, and a snail that got away, believe it or not, before we could even speculate on what type it was.

We also came upon a large gathering of about 30 American Robins (Turdus migratorius). Presumably they liked the shelter of the creek channel, the water source, and the supply of berries left on bushes and vines. These were mostly Common Buckthorn (Rhamnus cathartica) and wild grapes (Vitis sp.). A Blue-headed Vireo (Vireo solitarius) was a nice find, thanks to Erik.

We looked at trees, including some very large Bur Oaks (Quercus macrocarpa) and some that might be hybrids. We saw some mushrooms that seem a good match for Elm Mushroom (Hypsizygus ulmarius), growing on Manitoba Maple (Acer negundo). Maybe they were something else. We were not sure, but we photographed them from many angles and put them on iNaturalist.

At the end of our walk near the Queensway (Highway 417) we came upon the interpretive panel suggesting we “Discover Pinecrest Creek.” That seemed like a fine idea, even in hindsight. I hope to explore some more, both upstream and downstream. The area might feel the impact of future LRT development, so it will be interesting to keep an eye on it. A quick Internet search revealed that lots of people already do.

An interpretive panel tells of bit of Pinecrest Creek’s urban story