McCune, Jenny L.

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Now showing 1 - 5 of 5
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    Do traits of plant species predict the efficacy of species distribution models for finding new occurences?
    (Wiley, 2020) McCune, Jenny L.; Rosner-Katz, Hanna; Bennett, Joseph R.; Schuster, Richard; Kharouba, Heather M.
    Species distribution models (SDMs) are used to test ecological theory and to direct targeted surveys for species of conservation concern. Several studies have tested for an influence of species traits on the predictive accuracy of SDMs. However, most used the same set of environmental predictors for all species and/or did not use truly independent data to test SDM accuracy. We built eight SDMs for each of 24 plant species of conservation concern, varying the environmental predictors included in each SDM version. We then measured the accuracy of each SDM using independent presence and absence data to calculate area under the receiver operating characteristic curve (AUC) and true positive rate (TPR). We used generalized linear mixed models to test for a relationship between species traits and SDM accuracy, while accounting for variation in SDM performance that might be introduced by different predictor sets. All traits affected one or both SDM accuracy measures. Species with lighter seeds, animal-dispersed seeds, and a higher density of occurrences had higher AUC and TPR than other species, all else being equal. Long-lived woody species had higher AUC than herbaceous species, but lower TPR. These results support the hypothesis that the strength of species–environment correlations is affected by characteristics of species or their geographic distributions. However, because each species has multiple traits, and because AUC and TPR can be affected differently, there is no straightforward way to determine a priori which species will yield useful SDMs based on their traits. Most species yielded at least one useful SDM. Therefore, it is worthwhile to build and test SDMs for the purpose of finding new populations of plant species of conservation concern, regardless of these species’ traits.
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    Context-dependent interactions and the regulation of species richness in freshwater fish
    (Nature Publishing Group, 2018) MacDougall, Andrew S.; Harvey, Eric; McCune, Jenny L.; Nilsson, Karin A.; Bennett, Joseph; Firn, Jennifer; Bartley, Timothy; Grace, James B.; Kelly, Jocelyn; Tunney, Tyler D.; McMeans, Bailey; Matsuzaki, Shin-Ichiro S.; Kadoya, Taku; Esch, Ellen; Cazelles, Kevin; Lester, Nigel; McCann, Kevin S.
    Species richness is regulated by a complex network of scale-dependent processes. This complexity can obscure the influence of limiting species interactions, making it difficult to determine if abiotic or biotic drivers are more predominant regulators of richness. Using integrative modeling of freshwater fish richness from 721 lakes along an 11o latitudinal gradient, we find negative interactions to be a relatively minor independent predictor of species richness in lakes despite the widespread presence of predators. Instead, interaction effects, when detectable among major functional groups and 231 species pairs, were strong, often positive, but contextually dependent on environment. These results are consistent with the idea that negative interactions internally structure lake communities but do not consistently ‘scale-up’ to regulate richness independently of the environment. The importance of environment for interaction outcomes and its role in the regulation of species richness highlights the potential sensitivity of fish communities to the environmental changes affecting lakes globally.
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    Assessing public comitment to endangered species protection: a Canadian case study
    (Canadian Science Publishing, 2017) McCune, Jenny L.; Carlsson, Anja M.; Colla, Sheila; Davy, Christina; Favaro, Brett; Ford, Adam T.; Fraser, Kevin C.; Martins, Eduardo G.
    Preventing the extinction of species will require limiting human activities in key areas, but it is unclear to what extent the public is committed to these limits and the associated costs. We commissioned an online survey of 1000 Canadians and asked them if it is important to prevent the extinction of wild species in Canada. We used specific scenarios illustrating the need for limits to personal activities, private property rights, and industrial development to further test their support. The respondents were strongly committed to species conservation in principle (89% agree), including the need to limit industrial development (80% agree). There was less support for limiting private property rights (63% agree), and more uncertainty when scenarios suggested potential loss of property rights and industry-based jobs. This highlights the high level of public concern regarding the economic impacts of preventing extinctions, and the need for more programs to encourage voluntary stewardship of endangered species on private land. Opinion polls that measure public support for conservation without acknowledging the concessions required may result in overly optimistic estimates of the level of support. Most Canadians in our sample supported endangered species conservation even when the necessity of limiting human activities was explicitly stated.
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    Are we accurately estimating the potential role of pollution in the decline of species at risk in Canada?
    (Canadian Science Publishing, 2019) McCune, Jenny L.; Colla, Sheila R.; Coristine, Laura E.; Davy, Christina M.; Flockhart, D. T. Tyler; Schuster, Richard; Orihel, Diane M.
    Pollution is a pervasive, albeit often invisible, threat to biodiversity in Canada. Currently, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) relies on expert opinion to assess the scope (i.e., the proportion of a species’ population that may be affected) of pollution to species at risk. Here, we describe a spatially explicit, quantitative method for assessing the scope of pollution as a threat to species at risk in Canada. Using this method, we quantified the geographic co-occurrence of 488 terrestrial and freshwater species and pollution sources and determined that, on average, 57% of the mapped occurrences of each species at risk co-occurred with at least one pollution source. Furthermore, we found a weak correlation between the scope of the threat of pollution as assessed by COSEWIC expert panels and the geographic overlap of species occurrences and pollution sources that we determined with our quantitative method. Experts frequently identified scope of pollution as absent or negligible even for species with extensive co-occurrence with pollution sources, especially vascular plants. Clearly, a quantitative approach is needed to make accurate estimates of the scope of pollution as a threat to species at risk in Canada.
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    Conserving plant species at risk in Canada: land tenure, threats, and representation in federal programs
    (Canadian Science Publishing, 2020) McCune, Jenny L.; Morrison, Peter D. S.
    Fully 37% of species listed under Canada’s Species at Risk Act (SARA) are plants or lichens. The law does not automatically protect species on private land, and it is unknown how many at-risk plants grow mainly on private land. We analyzed official status reports and related documents for 234 plant species at risk to determine land tenure and evaluated differences in threats and changes in status. We also assessed how well plants were represented in two federal programs: the Natural Areas Conservation Program (NACP) and the Habitat Stewardship Program (HSP). Of SARA-listed plant species, 35% have the majority of their known populations on private land while <10% occur mostly on federal land. Species growing mainly on private land were no more or less likely to decline in status over time compared with others. Plant species at risk were less likely than other taxonomic groups to be found on land protected under the NACP. The proportion of HSP projects targeting plants is well below the expected proportion based on the number of listed species. We recommend that policy-makers promote and prioritize actions to increase the representation of plant species in federally funded programs, especially on private lands.