Subscribe to RSS Feed

A Decline in Areal Extent of Noxious Weeds at the Rock Creek Confluence Site in Clinton, MT

Katie E. Andrews, University of Montana
Patrick Benson, The University Of Montana
Ira Moll, University of Montana

Disturbances such as fire, grazing, land clearing, and flooding are important in determining the diversity and composition of plant communities. While disturbance can help maintain this diversity, it can also open up niches that fast growing nonnative plants can exploit, including noxious weeds that displace native plants and degrade habitat quality for wildlife. Controlling noxious weeds is a top priority for land managers, but can be challenging without relevant data on the location, areal extent, and intensity of infestations. One approach for providing such information is to conduct a weed inventory by mapping infestations present. For this project we have partnered with Five Valleys Land Trust to examine changes in noxious weeds over five years at the 300-acre Rock Creek Confluence (RCC) property outside of Clinton, MT. This site was subject to over a century’s worth of grazing and was more recently disturbed by the early stages of subdivision development. It is now infested with numerous noxious weed species. We inventoried seven noxious species that were of highest concern to managers utilizing ArcGIS field recorders to detail infestation characteristics. The seven invasive species inventoried include: oxeye daisy, dalmatian toadflax, leafy spurge, spotted knapweed, common tansy, perennial pepperweed, and hoary alyssum. Over the five years there was a 7% decrease in overall weed acreage. The species with greatest areal extent were spotted knapweed, leafy spurge, and common tansy. Two out of the three species (spotted knapweed and leafy spurge) both decreased in acreage by 15% over five years, and are thus responsible for the majority of the net weed reduction. The small decreases in acreage invaded for some species suggests that the weed treatments at the RCC property may be slowing if not reversing the spread of the most ubiquitous invaders.

Aquatic Community Composition Shift to Nitrogen Fixing Organisms

Nicholas Barnett Carpenter

Abstract. All aquatic organisms must assimilate the essential nutrient, nitrogen, which can be done through different pathways, including assimilation of nitrate or the utilization of atmospheric nitrogen via nitrogen fixation. We examined the Upper Clark Fork River in Montana in order to determine the extent to which nitrogen fixation provides nitrogen to aquatic organisms during the summer months when nitrate becomes scarce. We used an established experimental technique known as acetylene reduction, in which the rates of acetylene reduction serve as a proxy for nitrogen fixation. Epilithic biofilms were collected via rocks covered in algae from 3 locations on the river, and incubated in the river for 2 hours in clear plastic chambers with air, river water, and acetylene gas. Headspace samples were then drawn from these chambers and analyzed for ethylene, the product of acetylene reduction, via the analytical technique known as gas chromatography. The results showed that nitrogen fixation did occur during the summer months coinciding with low nitrate levels. Concomitantly, as readily available nitrate was depleted during the productive summer months, we observed a shift in aquatic community composition from green algal species that are non-nitrogen fixing (i.e., Cladophora) to a known nitrogen-fixing species (Nostoc). This work ties important ecological function to community composition during progressive N limitation of primary production.

Being the Beaver- a Dive into Beaver Mimicry and Nutrient Cycling

Kenna Karjala

The North American Beaver (Castor Canadensis), being both an ecosystem engineer and keystone species, used to dominate the North American riparian landscape until they were trapped into near extinction. Their absence has been felt on degraded riparian ecosystems. Restoration practitioners have recently brought the ideas of beavers back onto the landscape through beaver mimicry. Beaver mimicry is the restoration technique of mimicking the structure and function of beavers in a landscape to restore degraded ecosystems through the use of man-made replicates of beaver dams called beaver dam analogues (BDAs). While this technique is relatively cheap, mimics natural events, and might encourage the return of beavers to the streams, there is not much known about the impacts of beaver dams on the organic matter inherent to all streams. I will be studying the impacts of BDAs on organic matter in streams as part of a larger project on BDA impacts on streams run by Phd student Andrew Lahr in collaboration with the Clark Fork Coalition and The Nature Conservancy. We will be implementing a BACI (Before, After, Control, Impact) test on three pairs of first-order streams in Western Montana. To measure the impacts of the dams on the quantity and quality of organic matter I will be collecting organic matter (fine and coarse particulate as well as dissolved) to determine what size fractions are common in the streams prior to and post BDA installation. The results from my project will give better insight into how this seemingly perfect restoration tool truly impacts streams at the base of the food web, which will allow for better implementation of them in the future.

Building Montana's First Firewise Demonstration Garden

Melody Hollar, University of Montana
Zachary Garibay, University of Montana, Missoula
Nathaniel Miller, University of Montana, Missoula
Ethan Smith, University of Montana, Missoula
William Stevens, University of Montana, Missoula
Maxwell Rebholz, Missoula County Office of Emergency Management

Worldwide, increasing wildfire frequency and magnitude present novel challenges for homeowners in the wildland urban interface (WUI). In addition to the threat wildfires pose to forest ecosystems, wildfires also have an unprecedented potential to damage and destroy human structures. This is especially true in Montana. In September, 2019, Verisk Wildfire Risk Analytics ranked Montana as the number one state facing high to extreme risks of wildfire, with an estimated 137,800 properties at risk. As we saw in the devastating fire in Paradise, California, most of the structure fires that occur in the WUI are not a result of direct flame contact from the main fire. Rather, they are mainly caused by embers landing on either the house or the surrounding property and igniting the vegetation or debris there. Homeowner fire risk is thus highly dependent on the selection and arrangement of vegetation and landscaping materials within a 100-foot defensive zone around the house. While this is a well-known scientific principle, public awareness of what safe landscaping may look like remains very low. To address this critical public awareness gap, we are collaborating with the Missoula County Office of Emergency Management to research, construct, and promote Montana’s first Firewise Demonstration Garden, which will be located on the University of Montana campus. By offering a visual model in a space accessible by the community, this garden will show homeowners how they can protect themselves and their families from a devastating house fire. We additionally intend to use our work to promote the development of other demonstrations in a range of ecozones to improve climate resilience and reduce state fire-related expenses on a national scale.

Courtship Singing in the Japanese Rhinoceros Beetle

Nathan Barton, University of Montana, Missoula

Male rhinoceros beetles (Trypoxylus dichotomus) wield an extreme weapon, a "pitchfork" shaped horn, that they use in battles with rival males over territories females visit to feed. The only places adult beetles can feed are at sap wounds on the sides of trees, and the biggest males with the largest weapons are best able to guard these feeding territories. As in other species with tusks, antlers, or horns, winning fights is expected to translate into winning opportunities to mate with females. However, female T. dichotomus routinely reject mating attempts by territorial males, forcing them to court by stridulatory 'singing'. Males sing courtship songs after they have mounted a female, by rubbing a ridge, on the dorsal surface of their abdomen, against a stippled surface on the underside tips of each elytron. I described, for the first time, the courtship songs of this species, and show that males alternate between two distinct song types: short bursts of harsh scraping (Song Type A) followed by gentler bouts of a smoother song that can persist for long periods of time (Song Type B). I used RAVEN software to characterize the properties of each type of song, and compared the songs of a sample of males, to test whether females might be able to assess the body size and/or physiological condition of a male through his song. I show that larger males produce lower frequency (Hz) songs than smaller males, and that males in better condition while courting (mass/body size) sing song type B at a faster rate (chirps/second). These results demonstrate that there are meaningful signals embedded within male courtship songs that females could use to assess the male. Future studies will be needed to test if and how females choose males in a system where female choice is traditionally overlooked.

Habitat Assessment to Enable Use of Dogs to Monitor At-risk Species in Nonguen National Reserve, Chile

Logan A. Brauer, University of Montana

Chile is undergoing one of the fastest rates of native ecosystem loss in the world, mostly due to largescale timber plantations, mining and agriculture. This loss of habitat has put nearly 75% of native forest tree species and endangered Chilean fauna at risk of extinction. For some types of forest and tree species, there are few remaining individuals and remnant patches. Because of this finding additional individuals and patches of endangered tree species is a conservation priority. However, surveying for rare species using conventional methods is cost and time intensive. Dogs are a promising cost-effective approach, but in order to design an effective search program using dogs, it is necessary to have sufficient ecological information on the area being searched, as well as information on risks to the dogs. This project is partnered with Working Dogs for Conservation (WDC) to enable search of five focal species. These species of interest are: Aegla concepcionensis (Tiger crab), Lycalopex fulvipes (Darwin’s Fox), Nothofagus alessendrii (Ruil tree), Pitavia punctata (Pitao tree), and Puma concolor (Puma). To fulfill the goal of preparation for trained dog search, I will assist WDC by 1) determining feral dog densities within priority search areas, 2) identifying priority habitat areas within the reserve, and 3) calculating forest density within these priority habitat areas. Using methods borrowed from similar habitat assessments done in conservation of endangered species, I will be able to identify variables that if found indicate possible presence of highlighted species. My assessment will allow WDC to use trained dogs to detect critically endangered species within Nonguen National Reserve, and ultimately conserve populations found.

Huckleberries, Bear-Grass and the Western Hemlock Looper

Adele R. Underwood, University of Montana

The western hemlock looper moth (Lambdina fiscellaria) is a major defoliator in conifer-dominated forests across western North America. For example, in the 1990’s the Columbia National Forest in Canada saw outbreaks that completely defoliated up to 50 continuous hectares. Outbreaks this large cause easily identifiable timber-related problems, but to date there has not been any literature published on how these outbreaks affect non-timber forest products such as huckleberries (Vaccinium globulare) and bear-grass (Xerophyllum tenax). From what I have observed in the field, the western hemlock looper uses these ecologically, economically, and culturally important understory species as habitat. In order to identify the impact of the western hemlock looper on these plant species first we must determine if they are in fact suitable food sources. I am conducting research to determine if there are (1) differences among food sources (huckleberries, bear-grass, or western hemlock) in rates of survival, growth-related index (weight gain per unit of time), or reproductive capacity (fecundity and egg size) of the western hemlock looper; and (2) differences in rates of herbivory by the western hemlock looper on these target plants (huckleberries, bear-grass, or western hemlock). The results of this study will better inform future research, conservation and management efforts.

Immunomodulation of Innate Immunity by a Bacteriophage

Autumn Robinson

Pseudomonas aeruginosa is an opportunistic pathogen that infects diabetic ulcers and the lungs of individuals with cystic fibrosis. Most strains of P. aeruginosa are themselves infected by Pf bacteriophages. Most bacteriophages are viral parasites that kill their bacterial host. Pf bacteriophages, however, have established a more symbiotic relationship with P. aeruginosa. For example, Pf bacteriophages do not typically lyse their bacterial host and aid in bacterial adhesion and biofilm formation. Recent work demonstrates that Pf virions have immunomodulatory properties that modulate mammalian immune responses in ways that promote infection initiation. Finally, Pf bacteriophages are abundant at sites of human infection suggesting that they are clinically relevant. However, the mechanistic details for how Pf bacteriophages modulate vertebrate immune responses are poorly understood. We have discovered that key Pf-mediated infection phenotypes observed in mice are synonymous in a Caenorhabditis elegans host-pathogen model. C. elegans is an ideal and widely used model to study complex host-pathogen interactions. For example, several components of innate immunity are evolutionarily conserved between C. elegans and vertebrates. Using strains of P. aeruginosa with and without Pf bacteriophages, we found that the presence of Pf bacteriophages significantly increases P. aeruginosa virulence against C. elegans. Furthermore, we find that C. elegans predation of P. aeruginosa induces Pf replication. We hypothesize that Pf bacteriophages are a defense mechanism against predators such as C. elegans and phagocytes. Using this model, we will identify the mechanisms underlying the immunomodulatory properties of Pf bacteriophages which may reveal new therapeutic approaches to treat or prevent P. aeruginosa infections.

Rescue from the Rhizosphere: AMF-induced Drought Tolerance in Conyza

Kian G. Speck, University of Montana, Missoula

Rescue from the Rhizosphere: AMF-induced Drought Tolerance in Conyza

Kian Speck and Ylva Lekberg

Due to global climate change, increasing occurrences of drought are likely to negatively impact plant populations. Plants have evolved a variety of mechanisms and adaptations to deal with water stress, such as osmotic adjustment, waxy leaves, and symbioses with arbuscular mycorrhizal fungi (AMF). Although roughly 80% of all land plants form associations with AMF, little is known about the mechanisms underlying AMF-induced drought tolerance. A plant that seems to benefit immensely from fungal symbioses is Conyza canadensis, or Canadian horseweed. Conyza canadensis is capable of thriving in drought conditions yet lacks typical xeromorphic traits such as deep roots and water storage organs, but it is highly colonized by AMF. This is surprising given that C. canadensis is a ruderal annual and inhabits recently disturbed areas where AMF abundance is typically low. Therefore, Conyza presents an excellent opportunity to understand the mechanisms that underlie AMF-induced drought tolerance. The objective of this research is to understand (1) to what extent does AMF mitigate water stress in C. canadensis and (2) by which mechanisms does AMF do this. To answer these questions, we will assess differences in leaf water potential, total biomass, photosynthetic rate, non-structural carbohydrates, abscisic acid levels, and percent mycorrhizal colonization of roots between C. canadensis plants grown in a greenhouse with and without mycorrhizal inoculation under three different watering regimes (control, moderate stress, and severe stress). This study will add to a growing body of knowledge on AMF-induced drought tolerance and provide insight on the ecology of Conyza canadensis.

Shifting Baselines: Documenting Long-Term Impacts of Climate Change on Intertidal Foundation Species in the Gulf of Maine

Jonathan G. Karlen, University of Montana, Missoula

The interaction of natural climate cycles, anthropogenic climate change, and weather events affect organisms on centennial through hourly timescales. Intertidal organisms are affected by both marine and terrestrial climate variables, adding to the complexity of identifying drivers of changing biodiversity in these ecosystems. The Gulf of Maine is one of the fastest warming areas of ocean in the world, and its rocky shores are home to diverse, productive intertidal communities. These intertidal communities include several foundation species, which have an outsized impact on intertidal and marine organisms at all tropic levels. Using a 40-year, student-collected record of intertidal biodiversity data from Appledore Island, Maine I have found that the relative abundance of several foundation species has increased, decreased, and remained steady over time. Associated climate records, including sea surface temperature, air temperature, precipitation, and wave height will be used to identify the environmental factors driving changes in intertidal organism abundance and community composition. This research will provide a more nuanced understanding of how climate change is restructuring intertidal communities.

Singing Beetles? Figuring out how male rhinoceros beetles produce their courtship songs.

Devin Hunt
Nathan Barton
Chelsey Caldwell
Cole Sander
Romain Boisseau
Cerisse Allen
Douglas J. Emlen

Insects produce sound in wildly-diverse ways, from the vibrating wings of chirping crickets to the pulsating tympanum of whining of cicadas. Beetles (order: Coleoptera) use sound in aggressive displays, alarm calls, and courtship sequences. Although all beetles appear to generate sounds using stridulation, where a plectrum, or pick, is rubbed against a pars stridens, or file, species differ in the size and location of these structures, resulting in a diverse mechanistic array of sound production within this order. The Japanese rhinoceros beetle, Trypoxylus dichotomus, was recently observed stridulating during courtship sequences; however, the mechanism of sound production, including the body parts involved and their fine structure, were unknown. I used videos of singing males, topical applications of nail polish to putative file structures, and light and scanning electron microscopy (SEM), to localize and characterize the stridulatory apparatus. Here, I show that the pars stridens is located on the inside apical tip of each elytron, and it is scraped by a plectrum located on the dorsal surface of the abdomen. By either pumping the abdomen forward and back, or swiping it side to side, males are able to produce two distinct types of acoustic signals. Future studies will explore the properties of the male courtship song and the details of female preference.

Temperature effects on moose (Alces alces) activity patterns in Isle Royale National Park

Isabella C. Evavold, University of Montana, Missoula

Moose (Alces alces) in Isle Royale National Park impact the ecosystem by browsing tree species and serving as the primary food source for wolves. As a heat-sensitive species, moose are susceptible to the impacts of climate change in the southern extent of their range which includes Isle Royale. Understanding how temperature impacts moose behavior is valuable and can be used to predict how moose may respond to changing temperature in the future. GPS enabled radio-collars with three-axis accelerometers were used to collect one year of temperature and activity data from 19 cow moose in Isle Royale National Park. The data was used to test the relationship between moose activity cycles and temperature using linear regression. Results show that moose activity patterns do change based on temperature. The relationship between temperature and moose behavior can be used to estimate moose browsing impact which determines food availability over time. Understanding the relationship between temperature and moose activity can be used to predict change in moose behavior in response to climate change, which would disrupt the successional progression of vegetation communities and alter the greater Isle Royale ecosystem in the future.

The Study of AKR1B10 Enzymatic Activity and Expression for Increasing Endogenous all trans-Retinoic Acid in the Skin

Kassandra L. Boshae, UofM

Retinoic acid (atRA) is used throughout the body as a signaling molecule, and is important in cellular differentiation for many different cell types. atRA is a product of the retinol metabolism pathway. atRA is generally produced within cells by conversion of Retinol (ROL) into Retinaldehyde (RAL). RAL is then either irreversibly converted to atRA or is converted back to ROL via aldo-keto-reductase 1B10 (AKR1B10), thereby lowering the concentration of atRA. This makes AKR1B10 an interesting target for therapies and treatments for many different diseases and conditions. We hypothesized that natural and synthetic compounds would inhibit AKR1B10 activity and increase concentrations of endogenous atRA. To test this, we performed enzyme kinetic assays and RT-qPCR. Specifically, E. coli were transformed with an AKR1B10 plasmid, ABM-pPB-N-His, under kanamycin selection. To induce AKR1B10 expression, cultures were then treated with 100uM IPTG and FPLC was used to purify AKR1B10 protein. Gel electrophoresis confirmed the purified protein was ~37 kDa. We then evaluated our panel of natural and synthetic compounds for inhibition of AKR1B10 in kinetic studies measuring the conversion of NADPH to NADP+. Additionally, healthy adult keratinocyte monolayers were cultured with our panel of AKR1B10 inhibitors for RT-qPCR analysis of differentiation and proliferation markers including KRT10, Involucrin, Ki67, AKR1B10 and atRA responsive genes including KLK13, STRA6, and NRIP1. Interestingly, AKR1B10 expression was modulated by culture calcium concentration and retinoids, suggesting differentiation-state dependent effects. Together, we have found a small number of compounds that show some promising AKR1B10 inhibition, which would increase endogenous atRA concentrations. Further study is warranted to better understand AKR1B10 expression in the skin and to determine overall efficacy.