Great Basin College

Understanding the regeneration niche is of critical importance for the conservation of rare plants, yet species-specific information is often lacking for key components of the plant life cycle such as seed dormancy and germination. We conducted a detailed study of the regeneration niche for Ivesia webberi, a U.S. federally threatened forb that is endemic to the Great Basin Desert. Using seeds collected from 11 populations across a span of years, we investigated seed storage behavior, embryo morphology, and interannual and interpopulation seed viability, while testing the efficacy of alternative nondestructive methods to assess seed viability. We also studied the effects of various pre-incubation and incubation treatments on germination rates, speed, and synchrony. An examination of x-ray images showed that I. webberi have non-endospermic seeds with spatulate embryos. We observed a significant reduction in seed viability over three years, suggesting a recalcitrant storage behavior. Seed viability exhibited significant interannual, but not interpopulation, variation across 11 I. webberi populations. Both the x-ray and multispectral imaging are promising nondestructive methods that can replace the widely used, but destructive, tetrazolium test. Across all 68 germination treatments, seed germination was higher, faster, and more synchronized under warmer cold-stratified incubation temperatures. Seed germination was significantly increased by pre-incubation chilling and reduced by pre-incubation heat treatments, while pre-incubation and incubation light exposures had no effect. Both the seed embryo morphology and germination experiments suggest physiological dormancy in I. webberi. Results suggest that warmer and shorter winters, such as are consistent with predicted climate change, could increase germination of I. webberi seeds.

The application of statistical analysis software programs has proven useful for the investigation of rockfall runout distance along a designed slope. Rockfall modeling programs are continually being upgraded with more sophisticated analysis tools, such as the use of the rigid body versus lump mass models. Engineers at mine sites utilizing the software may have varied experience related to these models, their associated input parameters, and how to interpret the generated results. To address this concern, researchers at the Spokane Mining Research Division (SMRD) of the U.S. National Institute for Occupational Safety and Health (NIOSH) investigated the influence of slope height, slope angle, slope material, and rock size for both rigid body and lump mass models in a 2-D statistical analysis program. Based on a literature search and industry input, specific ranges common to that of an open pit mining environment were chosen for each of the input parameters to determine 90% rock runout distance as well as their sensitivity to change. Data collected from this numerical analysis and simulation will be compared to empirical rockfall data gathered through the duration of the Highwall Safety project conducted by NIOSH from 2022-2026.

Home ranges have long been studied in animal ecology. Core areas may be used at a greater proportion than the rest of the home range, implying the core contains dependable resources. The Pacific fisher (Pekania pennanti (Erxleben, 1777)) is a rare mesocarnivore occupying a small area in the Sierra Nevada Mountains, California, USA. Once statewide, fishers declined in the 1900s due to trapping, habitat fragmentation, and development. Recently, drought induced by climate change may be affecting this population. We examined space use of fishers in their core versus their home range for levels of anthropogenic modifications (housing density, road density, silvicultural treatments), habitat types, and tree mortality. We found core areas contained more late-successional forest and minimal human activity compared with their territory. Their core had higher levels of dense canopy and higher amounts of conifer cover, while minimizing the amount of buildings, developed habitat, and low canopy cover. Fishers may in effect be seeking refugia by minimizing their exposure to these elements in their core. Conserving landscape components used by fishers in their core areas will be important for the persistence of this isolated population.

The Alpine Treeline Warming Experiment (ATWE) was a common garden-climate manipulation experiment set up across an elevation gradient in Niwot Ridge, in the Front Range of the Colorado Rocky Mountains, USA. The project sought to learn more about the effects of climate change on alpine and subalpine ecosystems, namely tree species ranges and alpine plant communities. Plots were experimentally manipulated using infrared heaters set up to warm plots to temperatures comparable to those projected for the year 2100. Other treatments include watering, and a combination of watering and heating. Three sites were set up at different elevations to study three tree species, with the highest-elevation “Alpine” site ( ~3540 m) containing twenty additional plots to study alpine plant communities. Data in this package originate from these unseeded alpine plots. To evaluate soil nitrogen availability given site treatments, resin bags were deployed, removed, and extracted annually to produce ammonium and nitrate/nitrite readings.--------------------------------------------------Data files within this archive are in comma-separated-values (.csv) and Microsoft Excel (.xlsx) formats. .csvs can be read and opened by Microsoft Excel, R, or any other simple text-editing software, and .xlsx files can be opened using Microsoft Excel. Geospatial data associated with this package are in .kml and ESRI shapefile (.shp) formats. .kml files can be read using Google Earth or Google Maps, and shapefiles can be read with any software compatible with the file type, such as QGIS or ESRI’s ArcMap suite.Data files in this package - excluding “Winkler_2019_ALPO_inorganic_N_allyears.csv” - are provided in both Microsoft Excel and .csv formats, for added accessibility and flexibility in workflows. File contents are identical.

Abstract Humans are playing an increasingly large role in the expansion of invasive species' distributions, but few (if any) studies have evaluated anthropogenic factors associated with intentional translocation of invasives. The wild pig (Sus scrofa) is an extremely destructive and rapidly expanding invasive species whose movement is thought to be facilitated by humans. We sought to (1) identify a suite of genetic markers that can be applied to population genetic analyses of wild pigs, (2) find quantitative evidence of human‐mediated dispersal of wild pigs, and (3) determine which anthropogenic factors were associated with their translocation. We identified 43 polymorphic microsatellite loci and employed population genetic analyses to evaluate population structure and movement of wild pigs among populations in California,USA. Hierarchical Bayesian models were used to evaluate the influence of anthropogenic covariates on wild pig movement, and to predict migration risk. Natural dispersal of wild pigs among populations was low, as indicated by a large number of genetic clusters (K = 21), significant population differentiation, and low rates of recent migration. This suggests that the observed movement resulted from human‐mediated translocation. Movement of pigs was positively predicted by the number of domestic pig farms, the number of captive game hunting farms, the amount of public land, the number of wild pigs harvested by hunters, and the number of game outfitters. While hunting has been hypothesized to play a role in wild pig movement, our study is the first to provide quantitative evidence of such a relationship. We argue that future efforts to manage invasive species must consider the potential role of humans in their dispersal.

Digital infrared remote camera traps were placed at the entrance of twelve caves in Great Basin National Park, Nevada during the summer of 2013 to assess the wildlife use of cave entrances. The use of caves by surface wildlife is a major nutrient source for cave organisms that spend their entire lives underground. Cave entrances varied in size (0.9 to 50 m 2 ), cave length (10 to 1000 m), surface habitat (riparian versus pinyon/juniper), and management approach (gated versus no gate). Data from eight cave entrances are presented, with four other entrances removed from the analysis due to equipment failure. The cameras were deployed for a total of 372 trap days, with an average of 46.5 days per cave (range 28 to 62). The cameras captured 632 trap events, with separate events defined as more than an hour apart for the same species. Of the seventeen taxa documented, the most abundant species photographed were mice, chipmunks, humans, woodrats, and squirrels. Other species observed in cave entrances were cottontail rabbits, bats, skunks, foxes, insects, birds, and domestic dogs. Wildlife entered and exited caves most frequently between 1800 and 0600. Very little information has been previously documented about fauna using cave entrances, and this non-invasive, repeatable technique can help managers learn more about the dominant species using the entrance and twilight areas of the caves they manage, as well as peak use times.