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Ruminants have co-evolved with their gastrointestinal microbial communities that digest plant materials to provide energy for the host. Some arctic and boreal ruminants have already shown to be vulnerable to dietary shifts caused by changing climate, yet we know little about the metabolic capacity of the ruminant microbiome in these animals. Here, we use meta-omics approaches to sample rumen fluid microbial communities from Alaskan moose foraging along a seasonal lignocellulose gradient. Winter diets with increased hemicellulose and lignin strongly enriched for BS11, a Bacteroidetes family lacking cultivated or genomically sampled representatives. We show that BS11 are cosmopolitan host-associated bacteria prevalent in gastrointestinal tracts of ruminants and other mammals. Metagenomic reconstruction yielded the first four BS11 genomes; phylogenetically resolving two genera within this previously taxonomically undefined family. Genome-enabled metabolic analyses uncovered multiple pathways for fermenting hemicellulose monomeric sugars to short-chain fatty acids (SCFA), metabolites vital for ruminant energy. Active hemicellulosic sugar fermentation and SCFA production was validated by shotgun proteomics and rumen metabolites, illuminating the role BS11 have in carbon transformations within the rumen. Our results also highlight the currently unknown metabolic potential residing in the rumen that may be vital for sustaining host energy in response to a changing vegetative environment.

Because of their agricultural value, there is a great body of research dedicated to understanding the microorganisms responsible for rumen carbon degradation. However, we lack a holistic view of the microbial food web responsible for carbon processing in this ecosystem. Here, we sampled rumen-fistulated moose, allowing access to rumen microbial communities actively degrading woody plant biomass in real time. We resolved 1,193 viral contigs and 77 unique, near-complete microbial metagenome-assembled genomes, many of which lacked previous metabolic insights. Plant-derived metabolites were measured with NMR and carbohydrate microarrays to quantify the carbon nutrient landscape. Network analyses directly linked measured metabolites to expressed proteins from these unique metagenome-assembled genomes, revealing a genome-resolved three-tiered carbohydrate-fuelled trophic system. This provided a glimpse into microbial specialization into functional guilds defined by specific metabolites. To validate our proteomic inferences, the catalytic activity of a polysaccharide utilization locus from a highly connected metabolic hub genome was confirmed using heterologous gene expression. Viral detected proteins and linkages to microbial hosts demonstrated that phage are active controllers of rumen ecosystem function. Our findings elucidate the microbial and viral members, as well as their metabolic interdependencies, that support in situ carbon degradation in the rumen ecosystem. A combination of proteomics, metagenome-assembled genomes and heterologous gene expression experiments reveals a trophic system for carbon utilization in the moose rumen microbiome and provides insights into phage dynamics in this ecosystem.

Science communicators and scholars have struggled to understand what appears to be increasingly frequent endorsement of a wide range of anti-science beliefs and a corresponding reduction of trust in science. A common explanation for this issue is a lack of science literacy/knowledge among the general public (Funk et al. 2015). However, other possible explanations have been advanced, including conflict with alternative belief systems and other contextual factors, and even cultural factors (Gauchat 2008; Kahan 2015) that are not necessarily due to knowledge deficits. One of the challenges is that there are limited tools available to measure a range of possible underlying negative perceptions of science that could provide a more nuanced framework within which to improve communication around important scientific topics. This project describes two studies detailing the development and validation of the Negative Perceptions of Science Scale (NPSS), a multi-dimensional instrument that taps into several distinct sets of negative science perceptions: Science as Corrupt, Science as Complex, Science as Heretical, and Science as Limited. Evidence for the reliability and validity of the NPSS is described. The sub-dimensions of the NPSS are associated with a range of specific anti-science beliefs across a broad set of topic areas above and beyond that explained by demographics (including education, sex, age, and income), political, and religious ideology. Implications for these findings for improving science communication and science-related message tailoring are discussed.

The Nelchina Basin, located west of Glenallen, AK provides important moose Alces alces habitat throughout the year. However, previous research in this area has shown that the moose populations appear to be nutritionally limited by the available forage. The Nelchina Basin was deemed an intensive management unit to increase moose populations through predator control efforts and prescribed fires to increase the amount of available forage, including the 2004 Alphabet Hills fire. We quantified the available digestible energy (DE) and digestible protein (DP) during the summer of 2018 and 2019, as well as the winter in between, and availability of forages for moose within the burn perimeter and the adjacent unburned forest during the summer of 2019. We found that total canopy cover of the primary forage species was lower in the burned areas than in the adjacent unburned forest habitats, but only by 1%. Summer DP was significantly impacted by burn/unburn, caused by a 6% difference between the burn (avg = 2.58%) and the forest (avg = 2.43%). We also found a significant difference in DE and DP across the two sampling years. Although others have shown a positive effect of wildfire for herbivore populations, we found that the Alphabet Hills fire may not have made as much of a positive impact as in other systems. This project highlights the importance of research that quantifies both the availability of and the quantity of available food resources for herbivores.

Predation of moose (Alces alces) and caribou (Rangifer tarandas) calves by brown bears (Ursus arctos) has been extensively studied, because predation has population implications for both predator and prey species. Existing methods have provided estimates of population-level predation rates, but they have not been able to estimate kill rates by individual bears until recently and the accuracy of these estimates was unknown. Our objectives were to evaluate whether collars equipped with video cameras would be able to record predation events by brown bears and provide useful estimates of ungulate kill rates. We fitted 17 brown bears in the Nelchina Basin of Alaska, USA, with Global Positioning System (GPS) collars equipped with cameras in the spring of 2011, 2012, and 2013. We retrieved the collars in late June of each year to download the video data and associated GPS locations. To compensate for incomplete sampling, we constructed a calf risk model from previous calf mortality studies and used it to predict total calf kills for each bear through the end of June. The camera collars documented kill rates considerably greater than previous estimates. Median handling times by bears were 40 min for caribou calves and 60 min for moose calves. These short handling times should be considered by future researchers when trying to evaluate kill detectability and when factoring calf mortality into population models. We demonstrate that this technology can be successfully applied in the field and provide recommendations on the video sampling intervals necessary to detect predation rates.

Recent studies suggest that the growth and fecundity of northern ungulates may be coupled to their summer nutrition. Here, we compare summer dietary nitrogen availability of the five major browse plants (comprising ∼79% of the diet) of moose (Alces alces) in Denali National Park and Nelchina Basin, Alaska, USA. In recent years the productivity of Denali moose has been significantly higher than that of Nelchina moose, prompting this comparison. We examined the phenological progression of leaf nitrogen concentration, tannin-protein precipitation capacity, and digestible protein over three summers in both regions. We then modeled the potential nutritional consequences for a cow moose consuming representative diets on each range, predicting both net protein intake (NPI) and lean body mass accumulation each year. We found that leaf nitrogen and digestible protein decreased, while tannin-protein precipitation capacity increased throughout the summer for all forages. There was 23% more digestible protein in Denali leaves than Nelchina leaves on average, and this difference was significant in all three years. Tannins accounted for a large (mean = 46%) reduction in protein availability, suggesting a key role of these secondary compounds in the nitrogen balance of moose in these regions. Finally, our NPI model predicted that Denali cows were in positive protein balance 17 days longer than Nelchina cows and accumulated 18 kg more lean body mass over the summer, on average. We conclude that summer dietary nitrogen availability may act as a nutritional constraint on moose and suggest that more emphasis be placed on elucidating its role in population dynamics and conservation of northern ungulates.

In the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with >20% lichen cover (P < 0.001), greater than 1,250 kg/ha (P < 0.001) forage lichen biomass and stands older than 80 yr postfire (P < 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after ≥60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis-idaea) were necessary for predicting caribou use of winter range.

Caribou are an integral component of high-latitude ecosystems and represent a major subsistence food source for many northern people. The availability and quality of winter habitat is critical to sustain these caribou populations. Caribou commonly use older spruce woodlands with adequate terrestrial lichen, a preferred winter forage, in the understory. Changes in climate and fire regime pose a significant threat to the long-term sustainability of this important winter habitat. Computer simulations performed with a spatially explicit vegetation succession model (ALFRESCO) indicate that changes in the frequency and extent of fire in interior Alaska may substantially impact the abundance and quality of winter habitat for caribou. We modeled four different fire scenarios and tracked the frequency, extent, and spatial distribution of the simulated fires and associated changes to vegetation composition and distribution. Our results suggest that shorter fire frequencies (i.e., less time between recurring fires) on the winter range of the Nelchina caribou herd in eastern interior Alaska will result in large decreases of available winter habitat, relative to that currently available, in both the short and long term. A 30% shortening of the fire frequency resulted in a 3.5-fold increase in the area burned annually and an associated 41% decrease in the amount of spruce-lichen forest found on the landscape. More importantly, simulations with more frequent fires produced a relatively immature forest age structure, compared to that which currently exists, with few stands older than 100 years. This age structure is at the lower limits of stand age classes preferred by caribou from the Nelchina herd. Projected changes in fire regime due to climate warming and/or additional prescribed burning could substantially alter the winter habitat of caribou in interior Alaska and lead to changes in winter range use and/or population dynamics.

Management of large herbivore populations requires assessment of both the quality and quantity of habitats available to the animals. Classifying and quantifying their habitats, particularly the availability of forage, is often challenging because of the time and expense associated with collection of the appropriate data over large landscapes. Land-cover maps generated from remote-sensing imagery generally provide only qualitative information regarding species composition of the vegetation, and do not adequately quantify forage species availability. Our objective was to determine the feasibility of mapping important forage species for moose (Alces americanus) in South-central Alaska, USA, using fine-resolution aerial photography. We used infrared and color digital photography acquired at an altitude of 150m across 2 study areas with distinctly different vegetation to provide spectral data for supervised classifications of plant species using the maximum likelihood algorithm. We analyzed spring, autumn, and composite sets of the imagery to determine which imagery provides the most accurate classifications. Willow (Salixspp.) was separable from non-forage species in autumn images with an average overall accuracy of 76% in the Nelchina study area and 78% in Placer Valley. The classifications of composite images separated important moose forages, but with lower average overall accuracies (68% for Nelchina study area and 75% for Placer Valley) compared with the autumn classifications. Spring classifications were least accurate (57% for Nelchina study area and 63% for Placer Valley), likely because the green-up of plants in the spring occurred rapidly for all species in both study sites, and this resulted in relatively small differences in spectral response patterns between species.

We explored a one-step method of extracting plant cuticular hydrocarbons for the analysis of diet composition, intake, and passage rate of herbivores. Alkanes (waxes produced by plants) and long-chain alcohols (LCOHs) have traditionally been extracted via a sequence of saponification and esterification (S/E) separation techniques, which are labor- and time-intensive. We improved upon the alkane method by extracting samples in hexane using Dionex's Accelerated Solvent Extractor (ASE®; Dionex Corporation, Bannockburn, IL) with simultaneous purification of long-chain hydrocarbons using Florisil®(U. S. Silica, Berkeley Springs, WV) and Davisil®(W. R. Grace & Co.-Conn., Columbia, MD) solid-phase absorbents. This improvement allows for rapid preparation of samples for analysis of both alkanes and LCOHs for gas chromatography analysis. Recovery and quantification of plant alkanes was assessed using 5 forages that were phenologically and morphologically distinct and endemic to South-central Alaska, USA, to ensure both methods were tested under conditions for which they would be used. We found that recovery of alkanes was 20% higher (P< 0.0001) for the ASE method compared with the S/E method. Correcting for recovery, we found that both methods provided equivalent estimates of alkane concentrations (r 2= 0.9987). Recovery of LCOHs was significantly higher by 7.8% (P= 0.03) for the ASE method compared with the S/E method. Both methods provided similarly clean extractions, with satisfactory baseline and peak separations. We found that the single-step ASE process was effective in the extraction, purification, and quantification of both alkanes and LCOHs from plant materials, resulting in significant savings in time while using less corrosive solvents. Recoveries of both alkanes and LCOHs were higher for the ASE method.