Search

A distributional checklist of the sawflies (Hymenoptera) of Canada, Alaska (USA) and Greenland (Denmark) is presented. In total, 758 extant, described species, classified in 113 genera in 12 families are recorded. Of these, 729 (in 113 genera in 12 families) are reported from Canada, 183 (in 48 genera in 8 families) from Alaska, and 7 (in 1 genus) from Greenland. The list includes 69 new species records and 5 new generic records for Canada and 29 new species records and 7 new generic records for Alaska. The family Xiphydriidae is also newly recorded from Alaska. No new records are reported from Greenland. Eighty-four new combinations are proposed for species of Nematinae (Tenthredinidae). Distributions are listed for all species, for those in Canada by province or territory, except the province of Newfoundland and Labrador is divided into the island of Newfoundland and the region of Labrador. This inventory is compared with previous Nearctic and Palaearctic surveys, checklists and catalogues. [ABSTRACT FROM AUTHOR]

A checklist of 1246 extant, described species, classified in 346 genera in 18 families of Chalcidoidea (Hymenoptera) are reported from Canada, Alaska (USA) and Greenland (Denmark) based on examined specimens and published records up to December 31, 2020. Of the reported species, 1214 (in 345 genera in 18 families) are listed from Canada, 113 (in 58 genera in 10 families) from Alaska, and 26 (in 22 genera in 4 families) from Greenland. The list includes 235 new species records and 53 new generic records for Canada (no new family records). Forty-one new species records, 22 new generic records and the families Chalcididae and Eurytomidae are newly reported for Alaska. No new records were found for Greenland. Two species (in one genus) of Mymarommatoidea are reported from Canada. For each species in Canada, distribution is tabulated by province or territory, except the province of Newfoundland and Labrador is divided into the island of Newfoundland and the region of Labrador. The inclusion of known species from Alaska and Greenland results in the first comprehensive distributional checklist for the entire northern part of the Nearctic region. A brief review of the history of cataloguing Chalcidoidea in North America and a comparison of this checklist with four published checklists from the Palaearctic region is provided. [ABSTRACT FROM AUTHOR]

Little is known about how mutualistic interactions affect the distribution of species richness on broad geographic scales. Because mutualism positively affects the fitness of all species involved in the interaction, one hypothesis is that the richness of species involved should be positively correlated across their range, especially for obligate relationships. Alternatively, if mutualisms involve multiple mutualistic partners, the distribution of mutualists should not necessarily be related, and patterns in species distributions might be more strongly correlated with environmental factors. In this study, we compared the distributions of plants and vertebrate animals involved in seed‐dispersal mutualisms across the United States and Canada. We compiled geographic distributions of plants dispersed by frugivores and scatter‐hoarding animals, and compared their distribution of richness to the distribution in disperser richness. We found that the distribution of animal dispersers shows a negative relationship to the distribution of the plants that they disperse, and this is true whether the plants dispersed by frugivores or scatter‐hoarders are considered separately or combined. In fact, the mismatch in species richness between plants and the animals that disperse their seeds is dramatic, with plants species richness greatest in the in the eastern United States and the animal species richness greatest in the southwest United States. Environmental factors were corelated with the difference in the distribution of plants and their animal mutualists and likely are more important in the distribution of both plants and animals. This study is the first to describe the broad‐scale distribution of seed‐dispersing vertebrates and compare the distributions to the plants they disperse. With these data, we can now identify locations that warrant further study to understand the factors that influence the distribution of the plants and animals involved in these mutualisms. [ABSTRACT FROM AUTHOR]

We undertook a gap analysis of how protected areas represent the tree-species diversity within the Canadian boreal forest, as measured from Forest Resource Inventory (FRI) maps. We used a new compilation of Forest Resource Inventory designed to support ecological analyses over large areas and across jurisdictional boundaries. The analysis was stratified into four analytical regions determined by terrestrial ecozones. We calculated the relative abundance of species within regions, developed rarity criteria, and evaluated the relative abundances and prevalence of rare species. We characterized representation gaps when the abundance of a tree species in protected areas within an analytical region differed markedly (by more than a factor of 2) from the expectation, calculated as the product of regional abundance and the proportional area protected. Most species were well represented in the most species-diverse region ( n = 33), the Boreal Shield in eastern Canada, due apparently to a large number of relatively small protected areas in the southern part of the region. Some marked gaps existed in the more species-depauperate western zones, notably for montane conifers in the Boreal Plains. As is common for species abundance distributions, as few as five species accounted for 90% of total abundance in each zone. Relatively rare species were more numerous. Mostly associated with southern temperate or hemiboreal forests, these reached their highest prevalence and abundance in the managed forests of the Boreal Shield. Our work identified some gaps in representation in the protected areas network of Canada in western Canada, substantiates the use of species distribution mapping based on FRI data to inform conservation planning - including the identification of high conservation biodiversity elements for forest certification - and demonstrates the need for improved vegetation mapping in National Parks. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-latitude countries tend to contain the polar range-edge of many species that are nationally rare but globally common. This can focus national conservation efforts toward range-edge populations, whose conservation needs and value are disputed. Using plants in Canada as a case study, we ask whether national species-conservation rankings prioritize range-edge populations, and whether conservation priority is matched by habitat protection and research effort. We found that >75% of federally protected plants only occur in Canada peripherally, at the northernmost 20% or less of their total range, and that the most imperilled taxa had the smallest percentage of their range in Canada (endangered plants: median = 1.0%). Occurring peripherally in Canada was associated with higher threat even after accounting for range area, potentially because range-edge taxa experienced 85% higher human population densities in their Canadian range than non-peripheral taxa. High conservation priority was not matched by habitat protection, as more imperilled and more peripheral taxa had smaller fractions of their Canadian range in protected areas. Finally, peer-reviewed research on plants at-risk in Canada was low. Only 42% of plants considered at-risk in Canada had been studied in Canada, and only 11% of species with broad distributions outside Canada had been studied in the context of their wider geographic range—information that is critical to establishing their relative conservation value. Our results illustrate that plant conservation in Canada is fundamentally linked to conserving range-edge populations, yet edge populations themselves are understudied, a research gap we must close to improve evidence-based conservation. • Most plants deemed at-risk in Canada have <20% of their global range in Canada • More peripheral species tend to be more nationally at-risk • Plants at-risk in Canada had only 3.7% of their Canadian range (median) protected • Less than half of plants at-risk in Canada have been studied in Canada • The ecology of edge populations should be a research priority in northern countries [ABSTRACT FROM AUTHOR]

We explore the relationship between plant mating system (selfing or outcrossing) and niche breadth to gain new insights into processes that drive species distributions. Using a comparative approach with highly selfing versus highly outcrossing sister species, we test the extent to which: (1) species pairs have evolved significant niche divergence and less niche overlap, (2) selfers have wider niche breadths than outcrossers or vice versa, and (3) niches of selfers and outcrossers are defined by significant differences in environmental variables. We applied predictive ecological niche modeling approaches to estimate and contrast niche divergence, overlap and breadth, and to identify key environmental variables associated with each species' niche for seven sister species with divergent mating systems. Data from 4862 geo-referenced herbarium occurrence records were compiled for 14 species in Collinsia and Tonella (Plantaginaceae) and 19 environmental variables associated with each record. We found sister species display significant niche divergence, though not as a function of divergence time, and overall, selfers have significantly wider niche breadths compared to their outcrossing sisters. Our results suggest that a selfing mating system likely contributes to the greater capacity to reach, reproduce, establish, and adapt to new habitats, which increases niche breadth of selfers., (© 2019 The Author(s). Evolution © 2019 The Society for the Study of Evolution.)

Opportunistic citizen science (CS) programs allow volunteers to report species observations from anywhere, at any time, and can assemble large volumes of historic and current data at faster rates than more coordinated programs with standardized data collection. This can quickly provide large amounts of species distributional data, but whether this focus on participation comes at a cost in data quality is not clear. Although automated and expert vetting can increase data reliability, there is no guarantee that opportunistic data will do anything more than confirm information from professional surveys. Here, we use eButterfly, an opportunistic CS program, and a comparable dataset of professionally collected observations, to measure the amount of new distributional species information that opportunistic CS generates. We also test how well opportunistic CS can estimate regional species richness for a large group of taxa (>300 butterfly species) across a broad area. We find that eButterfly contributes new distributional information for >80% of species, and that opportunistically submitting observations allowed volunteers to spot species ~35 days earlier than professionals. Although eButterfly did a relatively poor job at predicting regional species richness by itself (detecting only about 35-57% of species per region), it significantly contributed to regional species richness when used with the professional dataset (adding ~3 species that had gone undetected in professional surveys per region). Overall, we find that the opportunistic CS model can provide substantial complementary species information when used alongside professional survey data. Our results suggest that data from opportunistic CS programs in conjunction with professional datasets can strongly increase the capacity of researchers to estimate species richness, and provide unique information on species distributions and phenologies that are relevant to the detection of the biological consequences of global change., (© 2018 John Wiley & Sons Ltd.)

Treeline advance has occurred throughout the twentieth century in mountainous regions around the world; however, local variation and temporal lags in responses to climate warming indicate that the upper limits of some treelines are not necessarily in climatic equilibrium. These observations suggest that factors other than climate are constraining tree establishment beyond existing treelines. Using a seed addition experiment, we tested the effects of seed availability, predation and microsite limitation on the establishment of two subalpine tree species (Picea engelmannii and Abies lasiocarpa) across four treelines in the Canadian Rocky Mountains. The effect of vegetation removal on seedling growth was also determined, and microclimate conditions were monitored. Establishment limitations observed in the field were placed in context with the effects of soil properties observed in a parallel experiment. The seed addition experiment revealed reduced establishment with increasing elevation, suggesting that although establishment within the treeline ecotone is at least partially seed limited, other constraints are more important beyond the current treeline. The effects of herbivory and microsite availability significantly reduced seedling establishment but were less influential beyond the treeline. Microclimate monitoring revealed that establishment was negatively related to growing season temperatures and positively related to the duration of winter snow cover, counter to the conventional expectation that establishment is limited by low temperatures. Overall, it appears that seedling establishment beyond treeline is predominantly constrained by a combination of high soil surface temperatures during the growing season, reduced winter snowpack and unfavourable soil properties. Our study supports the assertion that seedling establishment in alpine treeline ecotones is simultaneously limited by various climatic and nonclimatic drivers. Together, these factors may limit future treeline advance in the Canadian Rocky Mountains and should be considered when assessing the potential for treeline advance in alpine systems elsewhere., (© 2018 John Wiley & Sons Ltd.)