American ginseng: COSEWIC assessment and status report: chapter 9

Population Size and Trends

When the status report was written in 1988, 25 extant sites of ginseng from Ontario and 15 from Quebec had been studied in detail (White, 1988). Although the average size of colonies documented in the status report is over 100 plants, only the largest known colonies were selected for study. The average Ontario colony was estimated to be 10 to 20 plants and many sites contained only a few plants (White, 1988). An additional 80 locations from Ontario and 13 sites in Quebec could theoretically still be extant (White, 1988).

In this report, we are reporting 65 ginseng records for Ontario: 31 are known to be extant; 11 are known to be extirpated; and 23 are possibly extant (Appendix 1). Among those, 42 sites were studied in detail between 1996 and 1998. In 1997, 20 of the 25 previously-documented populations in Ontario were re-surveyed (Table 1). The results of these revisits are alarming: 25% of the 1988 sites had disappeared and 50% had declined. Harvesting was confirmed or suspected in 55% of the sites visited. Logging was suspected of causing declines in 25% of colonies investigated. In 1997 and 1998, an additional 22 sites were searched and counted in Ontario (Table 2). Of the 22 new sites surveyed, 27% had disappeared. Few of these new sites had a sufficiently reliable previous count to determine whether the population had increased or declined. If we evaluate the 42 locations surveyed in Ontario, the situation appears very precarious (Figure 2). Eighty-three percent of previously-documented Ontario populations have been extirpated or are threatened due to their small size (i.e. N< 170 plants, the Minimum Viable Population size for ginseng; Nantel et al., 1996; refer to Biology section). This figure should be seen as a conservative estimate, since only the larger sites were selected for this survey. The total plant counts documented for the province is 8619 plants, however, 70% of them were found in the two largest colonies.

The situation is also precarious in Quebec. The 1988 status report listed 15 extant sites and 13 possibly-extant sites for ginseng in Quebec. After much concentrated field effort over several seasons, the data bank of the “Centre de données du patrimoine écologique du Québec” reports 74 occurrences for ginseng (Appendix 2). From 1994 to 1998, 59 ginseng locations were studied in detail. Ten populations have been extirpated (i.e. 17%), and most of the extant ones are small (Figure 4). In Quebec, 75% of all ginseng populations recorded have been extirpated or are threatened (i.e. N<MVP). Fifteen viable populations are presently known, but nearly 50% of all plants known in the province (N=10,956) are found in only two large colonies (only one is protected). In Quebec, ginseng is concentrated in the south, in the Monteregian region, the most developed and urbanized area of the province. As a consequence, most populations are small and dispersed in a fragmented landscape where habitat loss and degradation is high. Harvest is less common in Quebec, observed in 15% of the sites sampled.

We have documented seven viable populations of ginseng in Ontario, and 15 in Quebec. Although these stations are considered viable on a biological point of view, none can be considered secure or protected. All face an uncertain future. Threats from harvest in Ontario and from habitat loss in Quebec are all clearly illustrated by these recent observations. Clearly, since the 1988 status report, harvest and habitat loss and degradation through logging and development have significantly reduced the ginseng population in Canada.

Table 4: Threats to Viable Ginseng Populations in Canada
Prov. Site Land Ownership/Usage Size Characteristics Threats (potential)
Ont   Private/Recreation > 500 Loss of vigor, probably due to observed disease. Very low seed production. Within town limit. Probably planted. Disease Development
Ont   Private/ Pasture 240 Colony occurs in a steepsided ravine protecting plants from cattle grazing in adjacent areas. Cattle Grazing Isolated habitat
Ont   Provincial Park/Recreation > 500 Immature colony with 2000 one-leaf plants. Half the mature plants were harvested in 1997. Very low reproductive potential. Harvest in 1997.
Highly visible from trail.
Ont   Private/Recreation 226 Mature colony with good seed production but very low recruitment. Logging
(Gravel pit)
Ont   Private/Unknown 192 Major decline since 1988 due to canopy opening from beaver activity. Island of deciduous forest in a large wetland complex. Habitat degradation
Isolated habitat
Ont   Provincial Park/Recreation 237 Immature population structure due to harvest. Half plants are seedlings. Harvest in the 80s.
Canopy affected by ice storm.
Ont   Private/Unknown > 500 Mature colony, very vigourous despite a major harvest (at least 105 mature plants and fruits). Harvest in 1997.
Que 001*QC 1 Wildlife National res./Recreation Conservation 467 Mature and moderately productive colony, but plants are small. Proportion of immature has increased from 1994 to 1998. Trail newly established nearby.
Que 003*QC Provincial Park/Recreation Conservation > 500 Several sub-populations dispersed in a protected area. A small colony was destroyed by disease in 1995. Harvested since 1995. Numerous trails expose this population to harvest. Harvested since 1995.
Que 004*QC Private/Sugar bush Recreation 366 Major losses in 1998 from ice-storm. Sharp decline since 1995 due to the establishment of a golf course nearby. Seed production reduced. Development
Major canopy loss from ice storm.
Habitat fragmentation.
Que 006*QC Private/Forestry Recreation > 500 Mature colony, very vigorous. Major damages from ice storm. Next to an ATV trail. Logging in 1995.
Major canopy loss from ice storm.
Que 0015*QC Private/ Sugar bush 262 Young population structure, but good regeneration. Numerous trails nearby for sap collection. (Logging)
Que 0020b*QC Private/ Forestry 480 A few sub-populations within mature habitat. Housing project projected. Logging
Que 0037*QC Private/ Forestry Recreation 300 A few mature sub-populations dispersed in mature forest. Numerous ATV trails. Deer grazing. Logging Canopy affected by ice storm.
Que 0051*QC Private/ Hunting club 320 Mature population but poor recruitment. (Logging)
Que 0052*QC Provincial Park/ Recreation 272 Mature colony with good seed production. Poor recruitment due to low seed viability. (Harvest)
Que 0055*QC Private/ Forestry 220 Mature colony with good seed production. Poor recruitment due to major seed predation. Nearby trail. (Logging)
Que 0058*QC Private/ Recreation Conservation 195 Immature colony with poor seed production. May have been harvested in the past. Numerous trails. Species rich habitat. Seed harvest reported.
Que 0059*QC Private/ Forestry 281 Mature colony with good recruitment reduced half size by selective logging. Logging in 1997.
Que 0062*QC National Park/ Recreation Conservation 222 Immature colony growing nearby trail. Few reproductive plants. Highly visible. Major damage from ice storm.
Que 0063*QC Private/ Forestry 248 Immature population originating from seed plantation. Established nearby trails. Harvest
Major damage from ice storm.
Que 0068*QC Private/ Nature trails Sugar bush 486 Mature colony, good recruitment. Mature maple forest highly fragmented by trails for sap collection and nature trails. Over 100 large plants dug in 1995. Highly visible. Harvest in 1995.

1 Locations are kept confidential. Site numbers correspond to EOCODE.


Page details

Date modified: