It is unclear how the environmental heterogeneity of the prairie biome of North America contributes to the biogeographic ranges of vascular plant species, particularly herbaceous taxa. We examined the spatial distributions of 30 abundant plant species of the grasslands of North America distributed among four functional groups: C 4 grasses, C 3 grasses, forbs, and woody species. For each species, we mapped its distribution using occurrence data from georeferenced herbarium specimens and a species distribution model (MAXENT). We then assessed which of several climate, soil, and elevation variables contribute to determining its range. On average, these 30 plant species are distributed over large areas, with an average range size of 1,989,750 km 2 . Temperature variables contribute the most to the MAXENT model for 27 of the 30 species. Size of range, abruptness of boundary edges, and location of range vary among all 30 species. Functional groups differ primarily in range size and the centroid of the ranges. Conservation of tallgrass, mixed-grass, and shortgrass prairie biomes will require a flexible strategy with widely distributed habitat over the Great Plains along both north-south and east-west gradients. [

The recent declines in eastern North American species of freshwater mussels have been well documented, but the status of western species has been comparatively understudied. However, various local and regional studies and anecdotal observations indicate that western mussels are also declining, suggesting the need for range-wide assessments of extinction risk and changes in freshwater mussel distributions. Using historic (pre-1990) and recent (1990-2015) occurrence data from across western states and incorporating observations of recent population dynamics, we assessed the extinction risk of western freshwater mussels according to the categories and criteria of the International Union for Conservation of Nature (IUCN) Red List. Percent change in occupied watersheds (by area) between historic and recent time periods was evaluated against IUCN-established thresholds. Additionally, we considered whether evidence of declines was also supported by reported observations of changes in abundance or occurrence in studied water bodies, watersheds, or regions. We also assessed the proportion of watersheds that have reduced species richness as compared with historic levels. We evaluated four western freshwater mussel taxonomic entities: three currently recognized species and one clade consisting of two currently recognized species. Of the four entities assessed, two are Vulnerable (Anodonta nuttalliana and Gonidea angulata), one is Near Threatened (Margaritifera falcata), and one is Least Concern (Anodonta oregonensis/kennerlyi clade). Freshwater mussel richness declined 35% across western watersheds by area, and among the most historically diverse watersheds, nearly half now support fewer species/clades. Future research and conservation efforts should prioritize identifying the proximate causes for these declines and preserving existing habitat and populations.

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Viruses in the family Rhabdoviridae infect a variety of hosts, including vertebrates, invertebrates, plants and fungi, with important consequences for health and agriculture. This study describes two newly discovered viruses of freshwater mussels from the United States.

Freshwater mussels (Unionida) are globally imperiled, in part due to largely unexplained mass mortality events (MMEs). While recent studies have begun to investigate the possibility that mussel MMEs in the Eastern USA may be caused by infectious diseases, mussels in the Western USA have received relatively little attention in this regard. We conducted a two-year epidemiologic investigation of the role of viruses in ongoing MMEs of the Western pearlshell (Margaritifera falcata) and the Western ridged mussel (Gonidea angulata) in the Chehalis River and Columbia River watersheds in the Western USA. We characterized viromes of mussel hemolymph from 5 locations in 2018 and 2020 using metagenomic methods and identified 557 viruses based on assembled contiguous sequences, most of which are novel. We also characterized the distribution and diversity of a previously identified mussel Gammarhabdovirus related to pathogenic finfish viruses. Overall, we found few consistent associations between viruses and mussel health status. Variation in mussel viromes was most strongly driven by location, with little influence from date, species, or health status, though these variables together only explained ~1/3 of variation in virome composition. Our results demonstrate that Western freshwater mussels host remarkably diverse viromes, but no single virus or combination of viruses appears to be associated with morbidity or mortality during MMEs. Our findings have implications for the conservation of imperiled freshwater mussels, including efforts to enhance natural populations through captive propagation.

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The northern forestfly, Lednia borealis (Plecoptera: Nemouridae) is a rare montane stonefly believed to be endemic to Washington. The species, first recognized as a valid taxon in 2010, is the only member of the genus Lednia known from the state. Like other species in its genus, it is found in mid- to high-elevation cold water habitat, including lakes, glacial-fed streams, and rheocrenes (channelized springs). Lednia species in general appear to be rare or at least rarely collected. Because of their reliance on alpine and subalpine habitat, Lednia may be especially vulnerable to threats associated with climate change. However, relatively little is known about this species, and distribution data are scarce. From 2015 to 2019, 94 sites were surveyed in order to document unmapped populations of Lednia borealis to improve range and distributional information from montane areas of Washington State. In this paper, we share locations of L. borealis documented to date, including collections from eight newly documented Lednia sites in the Mt. Baker and Glacier Peak Wildernesses in the Cascade Mountains of Washington, and report recent COI barcoding results. We also provide updated details on the species’ distribution, highlight a confirmed habitat association with glacial edge meltwater, and provide recommendations for future surveys.