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COSEWIC Assessment and Update Status Report on the Scouler’s Corydalis in Canada

Limiting Factors and Threats

An extensive network of logging roads has made large areas much more accessible in the Nitinat River and Klanawa River drainages. Current potential threats to Scouler’s corydalis, from logging, road and bridge building, recreational use and natural flooding are probably minor. These threats will have less impact on the total populations of Scouler’s corydalis since there are now known to be over 800 000 stems over a 275 km2 area. As well, Wildlife Habitat Areas prohibit logging, road and bridge building within the designated wildlife areas that protect over 400 000 stems. Road building and bridges have damaged some Scouler’s corydalis populations in the past; however, the total percentage of the population removed has been low. Some riverbank damage occurs when recreationalists have easy access to the rivers, but this is very minor at this time. Since the 1950s logging had a minimal direct effect on populations as this species rarely grows in harvestable forests. However, previous to this time in the early 1900s the equipment used in the removal of old growth stands could have reduced populations substantially.

Natural flooding, from time to time, removes riverbanks and floodplain populations. This would usually result in only temporary population reduction since the flooding creates new habitat and would provide a dispersal mechanism.

It is unknown whether inbreeding depression is a threat to the survival of Scouler’s corydalis populations. More research is needed on genetics and sexual and asexual reproduction to determine the risk of this threat. In addition, if sexual reproduction is important for the species, pollinator loss may be a threat.

Scouler’s corydalis is readily available in the horticultural trade, and because it is easy to obtain plants, collecting is not considered a threat.