Skip booklet index and go to page content

Recovery Strategy for the Incurved Grizzled Moss (Ptychomitrium incurvum) in Canada (Final)

2. Recovery

2.1 Rationale for Recovery Feasibility

The recovery of incurved grizzled moss is deemed not to be technically and biologically feasible for the following reasons:

  1. There are no known extant populations of incurved grizzled moss in Canada. The species is, however, relatively widespread in eastern North America, and populations there could be used as source material to reintroduce the species to Canada. Furthermore, there has been a documented, although unexplained, shift south in this species' range (COSEWIC 2002). This shift may make it impractical to reintroduce the species to the northern limit of its original range.

  2. It is unknown whether there is sufficient habitat for the species remaining in Ontario at the present time. “Without extant populations or a clear understanding of the habitat from which the only Canadian specimen was collected, it is not possible to assess habitat trends specific to the Canadian population” (COSEWIC 2002). However, as incurved grizzled moss is able to colonize several types of substrate that are abundant in Canada, including anthropogenic surfaces, it is unlikely that substrate availability is a limiting factor for this species. It is unknown where the nearest extant population is -- the species is considered historic in New York but may still occur in southern Michigan (COSEWIC 2002).

  3. The threats to the species and its habitat and what led to its extirpation are not understood and, therefore, cannot be avoided or mitigated at this time. It seems likely that incurved grizzled moss is limited by climatic factors; however, this has not been confirmed. There has also been an unexplained shift of the species' distribution to the south over the past century, which may have led to the extirpation of the species in Canada as well as New York State.

  4. It is unknown whether the necessary recovery techniques exist to reintroduce this species to Canada. Reintroduction techniques have not been developed or tested specifically for this species; however, recovery techniques for other mosses may exist and could possibly be used to assist in reestablishing a Canadian population.

The one and only record of incurved grizzled moss in Canada is only suspected, as it was found near the Canada–U.S. border almost 200 years ago, and the only possible recovery technique is reintroduction. Recovery is not recommended unless:

  1. the species is found in Canada,
  2. information becomes available on the species' biology in its northern range, and/or
  3. appropriate reintroduction techniques become available.

2.2 Recovery Actions

The recovery of this species is considered “not feasible” at this time and will not be pursued. This decision will be reexamined if the species is rediscovered in Canada.

However, it would be appropriate to monitor and conduct follow-up work (e.g. confirmation) on observations reported by individuals during surveys done for other species in southern Ontario.