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COSEWIC Assessment and Update Status Report on the Streambank Lupine (Lupinus rivularis) in Canada

Population Sizes and Trends

This species has not been studied in Canada before, and little data exists on the numbers of populations or numbers of individuals within a population (Table 1). Therefore, declines or increases in numbers, or trends in health or vigour cannot be assessed at this point. However, given that some collections from the extant sites span at least a ten year period, we at least know there is continuity of these stations.

Table 1. Lupinus rivularis: Extant Natural Populations in 2001.
 #LocationSubpopulationMature PlantsSeedlings1
1Sooke--
1
0
2Delta River Road--
45
100+
3Delta / Surrey Border2--
50
100+
4Surrey (Fraser Surrey Docks)a) railway bed #1
1
0
4Surrey (Fraser Surrey Docks)b) railway bed #2
11
30+
4Surrey (Fraser Surrey Docks)c) roadside
20
0
5Port Coquitlam (Pitt River Dyke)--
20
100+
6Port Coquitlam (Coquitlam River)--
100
200+

1 Because this is a perennial species that flowers from May to September, producing pods and dispersing seeds from June onwards, numbers of seedlings at each site vary from visit to visit as the summer progresses. The numbers given here represent seedlings observed on May 22, 2001.

2 A second sub-population of 11 plants was found in this vicinity in 1990 by Lomer, but was not rediscovered in 2001.

Extant locations

1. Sooke

A single plant was discovered at this site in full flower. It appeared to be about three or four years old. While this is not necessarily the site of the collection record by Anderson in 1926, it is likely that collection came from the immediate vicinity. The plant is vulnerable to annual flooding and scouring; however, this would appear to be a natural process for this species, and scouring may actually allow seeds from the seed bank to be uncovered and to germinate. This site possibly lies within a provincial park. The single plant was growing alone, with no associated species, in river rocks behind a low gravel ridge along a river (collection, 2001, Klinkenberg, UBC).

2. Delta River Road

2001 status:

Plants at this site occur both along the Canadian National and Burlington Northern Railway tracks, and on a low floodplain immediately adjacent to the tracks, in the municipal road allowance, along a creek bank leading directly to the Fraser River. Forty-five mature plants were counted, and more than 100 seedlings. The plants on the low floodplain may well represent the founding population for this site, and over time some plants have migrated up onto the railway bed where competition is low and the substrate quite suitable for the species. This site was severely impacted by summer (2001) spraying, and all the mature plants died off. However, a quick check in September 2001 revealed that the seedlings were doing well and were abundant. Plants at this site are growing in a bare gravel substrate (railway bed) and low silted floodplain site adjacent to the tracks. This site was first reported by Lomer in 1986, who recalls that plants were abundant (Lomer 2001 pers. comm.) (collection, 2001, Klinkenberg, UBC).

2002 Update:

Since we last checked this site in late summer 2001, major railway bed grading has taken place. All of the seedlings we counted then that survived the herbicide spraying have been wiped out. Fresh gravel has been piled alongside the tracks, directly on top of these seedlings, and much of the pre-existing gravel has been pushed outward during the grading process.

What is left of the population at this site is one dozen flowering plants of mixed ages on the small floodplain below the railway bed, and approximately two dozen newly germinated seedlings in the loose gravel at the edge of the railway bed grading area. These seedlings are at risk if further railway maintenance occurs.

Before and after photographs of the site are available and have been deposited with COSEWIC as archival material. The photographs are also available at this web site: http://www.geog.ubc.ca/~brian/lupinusrivularis.htm

3. Delta/Surrey Border

This population grows beside a municipal road on a low floodplain in an industrial development. Forty-five mature plants were counted, and at least 100 or more seedlings. This population occurs in a vulnerable situation where roadside spraying or mowing will impact on the population. Plants are presently strung out along the roadside, both in the open and under an open canopy of small trees, and around telephone poles. It appears that the site might be brushed periodically. Lomer reported a small subpopulation near here, although there is no previous collection (Lomer 2001 pers. comm.). The road allowance is leased by the municipality from the Fraser River Port Authority. Actual ownership of the road allowance is not clear (Fraser River Port Authority 2002 pers. comm.) (collection, 2001, Klinkenberg, UBC).

4. Surrey (Fraser Surrey Docks)

This site is a continuation of the low floodplain site described in #3 above, though separated by nearly two kilometres. Three subpopulations are reported here (Table 1), and it is possible that other subpopulations exist scattered along the railway yards. A total of 31 mature plants were recorded, with 30 or more seedlings. This site, like the one above, likely represents a residual population that has been reduced by industrial development and railway yarding along the floodplain. Two of the subpopulations at this site were previously reported by Lomer (subpopulations ‘a’ [1 plant] and ‘c’ [more plants than in 2001]), and a specimen was collected at one of them in 1990 (Lomer 2001 pers. comm.). Because of the close proximity of the three subpopulations, a collection was made at only one of them in 2001. However, photo records are available. There are several railway lines immediately adjacent to the populations, owned by different railway companies and / or the Fraser River Port Authority (Fraser River Port Authority 2002 pers. comm.). Ownership of the tracks in this area is shared by Canadian National Railway, Burlington Northern Railway, and the Fraser River Port/Railway. Precise ownership of the land on which these subpopulations occur will require detailed investigation and examination of land titles, easements, and management agreements (collection, 2001, Klinkenberg, UBC).

5. Port Coquitlam (Pitt River Dyke)

The plants at this site occur both on the municipality-owned dyke along the fence line, and on the other side of the fence on private property. The properties behind the dyke are located in an industrial subdivision that was built on a low floodplain area. It is likely that this is a residual population that has opportunistically moved on to the dyke. Twenty mature plants were counted and more than 50 seedlings.  Lomer recalls observing two patches in a similar location in 1993, but with fewer plants overall (Lomer 2001 pers. comm.) (collection, 2001, Klinkenberg, UBC).

6. Port Coquitlam (Coquitlam River)

The plants at this site occur both on the Canadian Pacific Railway bed as it approaches the river, and on the adjacent roadside verge, and likely represent a residual population that has opportunistically shifted onto the railway bed where competition is low. Railway maintenance operations (brushing and possibly spraying) have maintained a site with open gravelly substrate and no competition. This is the largest population of the species in Canada, with 100 plus mature plants, and more than 200 seedlings counted. Where the plants grow on the roadside verge, they are routinely mowed, and seem to still survive and set seed. Plants growing along the railway verge, just to the side of the tracks, were in excellent condition. The site is both railway-owned, and municipality-owned along the roadside verge, and the tracks traverse a municipality-owned park. The site was reported to have abundant plants by Lomer in 1998 (collection, 2001, Klinkenberg, UBC).