Microhabitat and ecology of the rare boreal endemic Lechea intermedia var. depauperata Hodgdon (Cistaceae)

Understanding the ecology and life history of rare species is critical to assessing their conservation status and developing effective management strategies. We examined the habitat and demography of impoverished pinweed (Lechea intermedia var. depauperata), a rare, narrowly endemic post-fire coloniser native to the Athabasca Plain of Canada, using a combination of germination tests, plant community assessments, and microclimate monitoring. In addition, we monitored demographic trends over three years in five of six known extant populations to explore the temporal dynamics of impoverished pinweed populations. Areas supporting impoverished pinweed populations were found to be warmer than adjacent areas during the growing season; however, warmer temperatures did not correlate with higher seed germination. Plant community composition varied little between occupied and unoccupied areas. Demographic assessments suggest the taxon is likely a short-lived perennial, and populations appear to be self-sustaining in the short term. Based on work presented here and in a previous study, we suggest that impoverished pinweed has several characteristics of inherently vulnerable taxa, and we recommend that population trends be monitored over time. Further, we recommend directions for future work to address identified outstanding knowledge gaps.