McCune, Jenny L.

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https://opus.uleth.ca/handle/10133/6392

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    Testing for synergistic effects of natural and anthropogenic disturbance on ecological communities at a landscape scale
    (Springer, 2024) Lloren, Jed I.; McCune, Jenny L.
    Context Anthropogenic and natural disturbances may interact synergistically, magnifying their individual effects on biodiversity. However, few studies have measured responses of ecological communities to multiple stressors at landscape scales. Objectives We use a long-term dataset to test for synergistic effects of anthropogenic and natural disturbance on plant community diversity and composition in a large protected area. Methods We quantified changes in plant communities over two decades in 98 plots in Waterton Lakes National Park, Canada. Fifty-three plots burned in a wildfire in the interim. We modeled the effects of wildfire, proximity to trails or roads, and their interaction on changes in species richness, community composition, relative abundance of disturbance-associated species, and colonization by exotic species. Results Interactions between wildfire and proximity to roads and trails affected all metrics except species richness. Only one interaction was synergistic: the relative abundance of disturbance-associated species following wildfire was magnified closer to recreational corridors. The other community metrics showed unexpected patterns. For example, plots with no exotic species in the baseline survey that burned in the wildfire were more likely to gain exotic species than unburned plots only when they were distant from recreational corridors. Conclusions Our study demonstrates interactive effects of natural and anthropogenic disturbance at landscape scales within a protected area. Plant community response to wildfire was influenced by proximity to recreational corridors, sometimes in surprising ways. As the frequency and severity of anthropogenic and natural disturbances both continue to rise, documenting the prevalence and magnitude of interactions between them is key to predicting long-term effects and designing mitigation strategies.
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    The state of plant conservation in Canada: a survey of practitioners
    (Canadian Science Publishing, 2024) McCune, Jenny L.; Baldwin, Sarah J.; Bennett, Joseph R.; Husband, Brian C.; Joly, Simon; Kraus, Daniel; Lamb, Eric G.; Vamosi, Jana C.; Van Natto, Alyson C.; Whitton, Jeannette
    Plants make up more than one quarter of all species listed under Canada’s Species at Risk Act, but very few have improved in status over time. Ineffective legal protections, lack of public awareness, difficulties in prioritizing species, and a scarcity of research relevant to the recovery of plant species at risk are some of the many challenges facing effective plant conservation in Canada. We used an online survey to ask 243 people who work in plant conservation or who do research in plant ecology or evolution to assess the state of plant conservation in Canada and to identify the actions needed to improve it. Most respondents agreed that Canada is underperforming or merely average when it comes to conserving plants. Based on their responses, we outline a set of recommendations that could form the basis of a national strategy for plant conservation in Canada. These include greater advocacy for habitat protection, connecting researchers with funding opportunities, supporting graduate students working on research related to plant conservation, increasing public awareness of plants, collaborating with and respecting Indigenous knowledge holders, promoting collaboration between researchers and local conservation groups, and increasing capacity to assess the status of species that are potentially at risk.
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    Dispersal limitation and seed predation drive rarity of a plant species at its range edge
    (Wiley, 2025) Neigel, Emma R.; Schwinghammer, Timothy D.; McCune, Jenny L.
    1. Understanding the causes of species rarity is a central goal in ecology. The three filters thought to predict if a species is present or not in a community are the suit- ability of abiotic conditions, dispersal limitation and biotic interactions. Theory emphasizes the importance of the availability of abiotically suitable habitat in de- termining occurrence frequency, especially for species at their range edge, where the amount of suitable habitat is predicted to decline. However, the relative influ- ence of these filters in driving species rarity is mostly unknown. 2. We used species distribution models (SDMs) to estimate habitat suitability based on broad-scale abiotic predictors for a rare plant species (Stylophorum diphyllum) at the northern edge of its global distribution. We tested the role of dispersal limi- tation by planting seeds in unoccupied sites that varied in their predicted habitat suitability and measured seedling emergence and seedling survival over 2 years. To manipulate the biotic interactions, we excluded seed predators by caging half of the seeds. We also measured the microclimate at each microsite, including soil moisture, temperature and canopy cover. 3. The habitat suitability estimated by the SDMs did not predict seedling emergence or short-term seedling survival. We found that dispersal limitation coupled with seed pre- dation was a significant predictor of seedling emergence, while microclimate, specifi- cally microsite temperature, was a significant predictor of short-term seedling survival. 4. Synthesis. Contrary to the assumption that species occur at a low frequency near their range edges due to a lack of suitable habitat, we found that dispersal limita- tion coupled with biotic interactions can drive rarity. If this is the case for many rare species at risk of extinction at their range edges, effective conservation strategies must incorporate assisted dispersal (i.e. translocations) into appropri- ate microsites and the management of biotic interactions to establish new popu- lations and ensure long-term persistence.
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    Habitat characteristics of Botrychium species in the Castle Region, Alberta, Canada
    (Brigham Young University, 2024) Chisholm, Trinitas; McCune, Jenny L.
    Moonwort (Botrychium Swartz) is a genus of ferns found in high diversity in the Rocky Mountains of southwestern Alberta, Canada. These small, cryptic plants are thought to prefer disturbed areas, such as trail sides. However, this idea may result from survey bias toward accessible areas near trails, or greater ease of spotting these plants in barren areas. Castle Provincial Park and Castle Wildland Provincial Park (CCWPP) are 2 recently established protected areas within this global hotspot of Botrychium diversity. Prior to 2018, provincial and international databases included only 30 records of Botrychium throughout CCWPP. Therefore, their frequency in the parks and their habitat preferences are not well understood. We used new records from the Castle region plus online herbarium records to build a genus-level species distribution model (SDM) and surveyed 24 sites of varying predicted suitability at least 100 m from trails. We then used all known records, including new records gathered during vegetation surveys, to assess habitat associations of any Botrychium species found throughout CCWPP. Botrychium occurred in a wide variety of vegetation types, with some species limited to one vegetation type. Overall, most Botrychium occurrences were on south-facing slopes, in grassland vegetation, 10–100 m away from official marked trails. We discovered 7 new occurrences in surveys at least 100 m from trails. Although 6 of the 7 new off-trail occurrences were found at sites with >40% suitability, the SDM was not a significant predictor of Botrychium occurrence. Our results show that Botrychium occurs across a wide range of vegetation types, topographic conditions, and proximity to trails and there are likely many undiscovered populations in CCWPP.
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    Comparing the effect of landscape context on vascular plant and bryophyte communities in a human-dominated landscape
    (Wiley, 2020) McCune, Jenny L.; Frendo, Christina J.; Ramadan, Mohammed; Baldwin, Lyn K.
    Aims: It is important to understand the effect of landscape context on biological communities to predict how biodiversity will be affected on human-dominated land-scapes. While many studies have tested the effects of landscape context on the spe-cies richness and composition of vascular plants, few have compared the responses of vascular plants and bryophytes on the same landscape. We sampled non-epiphytic bryophytes and vascular plants in 184 plots to test whether three landscape context factors measured four years or four decades previously could predict bryophyte or vascular plant species richness and composition after accounting for local factors.Location: Temperate forests and oak savannahs, Vancouver Island, British Columbia, Canada.Methods: We used model selection and comparisons to test the effects of surround-ing road density, total amount of forest, and distance to the nearest forest edge on species richness, species richness of non-disturbance-associated species, and com-munity composition after controlling for important local predictors including sub-strate availability and topography.Results: The species richness of non-disturbance-associated vascular plants was lower in plots with greater surrounding historical road density, and perennial stayer bryophyte richness declined with increasing historical road density and lower histori-cal forest amount, suggesting a potential extinction debt. Landscape context signifi-cantly affected total species richness and community composition of vascular plants, but not bryophytes.Conclusion: While bryophytes appear to be less sensitive overall to landscape con-text than vascular plants, disturbance-intolerant perennial stayer bryophytes may decline in the future in response to the increased road density and loss of forest cover that has occurred over the past four decades.