|Friday, April 22nd|
Samuel Brian Turner, University of Montana, Missoula
9:40 AM - 10:00 AM
Dam removal is increasingly used to restore stream ecosystems, however the ecological effects of this type of restorative action is under-studied. Benthic macroinvertebrates are commonly used as biological indicators of stream integrity when monitoring stream restorations. This study assesses the response of benthic macroinvertebrates to a small dam removal in Rattlesnake Creek, Montana. We examined benthic macroinvertebrate data collected from 2019-2021 to determine variation in community abundance and composition upstream, downstream, before and after dam removal and restoration. Macroinvertebrate community metrics were assessed, in relation to Montana specific biological and ecological integrity measures, to gain insight into the current states of Rattlesnake Creek macroinvertebrates. We measured indices values indicative of high biological diversity and environmental sensitivity, representative of relatively pristine stream systems of Western Montana. Our results show that there is variation from year to year, and that changes in macroinvertebrate communities were modest and largely confined to sites directly downstream and immediately following dam removal. It also showed that the macroinvertebrate community in the reach that had been restored was very similar to those both upstream and downstream. These results indicate that this dam removal and restoration project had a relatively limited influence on the benthic macroinvertebrate community within the adjacent stream reaches.
10:00 AM - 10:20 AM
Severe wildfires are more frequently entering urban areas causing billions of dollars of damage in the Western United States over the past decade. One approach for limiting the wildfire risk to urban homes is to adopt “firewise” landscaping approaches. These approaches focus on minimizing flammable materials near the home and landscaping with plants that don’t generate large quantities of flammable material. Highlighting these practices is important to reducing the dangers of wildfires. incorporating native, pollinator friendly plant species closes ecological gaps. An in depth review communicates the firewise principles that will help inform the community on ways to help prevent the potential spread of a wildfire in inhabited areas and improve ecological conditions overall.
Aubrey Benson, University of Montana, Missoula
10:20 AM - 10:40 AM
Revegetating riparian soils made bare during restoration is important to stabilize soils and minimize the spread of non-native invasive plants. Seeding is a commonly used approach for revegetation, but its efficacy and factors that limit its success remain understudied. It is known that nutrient availability can limit plant growth and establishment, and that seed addition rates can also play a role. However, the success of these approaches has varied, presenting an opportunity to study the optimization of revegetation techniques. In this study, we examined ways to increase the efficacy of reseeding riparian areas on a reach of Ninemile Creek in Western Montana by looking for evidence of nutrient limitation and seeding limitation. Ninemile Creek was historically degraded by placer mining, which covered the riparian areas with 10 meter tall gravel piles. Extensive restoration efforts have been conducted by Trout Unlimited in the Ninemile Valley through removing the gravel piles and reconfiguring the stream channel and floodplain. We established plots in a reach that had been restored in 2020 with a combination of nutrient additions and low or high density seeding rates. Our results suggest that nutrients were more limiting to the establishment of riparian plants than seed at this site, providing new insights to Trout Unlimited and others on how to optimize their revegetation efforts.
10:40 AM - 11:00 AM
The role of time as an important factor in restoration of riparian ecosystems toward a reference state is well known. Ecosystem engineers, such as beaver, can have substantial influences on ecosystem characteristics, and thus they may play a large role in ecosystem recovery, however the role of beavers in altering the rate of ecosystem recovery is not well described. In this study, we monitored the recovery of vegetation and soil characteristics at Ninemile Creek in western Montana. This site has been highly degraded by historic placer mining, which resulted in a stream channel bounded by ten-meter-high gravel piles, eliminating the riparian floodplain ecosystem. Restoration has consisted of gravel pile removal and configuration of a new river channel and connected floodplain. As recovery has proceeded, beaver have moved downstream from an upstream unmined reach. Our research examines the role of beaver activity and time in restoring the riparian ecosystem by comparing three reaches that were restored in 2014, 2016, and 2018. We gathered data from the three restored reaches as well as the upstream reference reach using point-line intercept transects to assess vegetation and surface cover. We also collected soil samples which we tested for soil moisture, soil organic matter, and the percent fine and percent coarse material. Additionally, we surveyed each restored reach to assess the number of beaver structures including dams and lodges. The presence of beaver structures led to soil with more moisture and higher organic matter content and was associated with higher vegetation cover, especially of woody vegetation. Because the oldest restored reach also was the only one with beaver structures, we cannot separate the influence of time from the influence of beaver. However, comparing data from all three reaches to the same data collected two years previously shows that beavers may increase the pace of restoration.
Eugene C. Byron, University of Montana, Missoula
2:00 PM - 2:20 PM
The Araucaria araucana tree is endemic to a small range of Chile and Argentina. This ancient gymnosperm dates back to the Tertiary period and can live over 1300 years. Within Chile, remaining stands have been fragmented by exotic plantations, logging pressures, and human disturbance. Though this tree is resistant to disturbance and fire, human pressures and the removal of frequent fire are giving other species a competitive advantage over A. araucana. Current populations are clustered along the coast and the Andean mountains. However, there is a lack of knowledge about the spatial patterns of A. araucana trees within stands. Overstory spatial patterns of native forests are a key attribute informing accurate restoration. We are proposing to characterize overstory tree spatial structure for both coastal and Andean sites to determine the frequencies of individual trees, small clumps, and large clumps. We will also examine the effects of overstory spatial structure on understory composition and regeneration of this tree. By sampling remaining native stands, this study will serve to improve future restoration efforts and develop accurate reference sites.
Lauren E. Spaeth, The University Of Montana
2:20 PM - 2:40 PM
Invasive species have negative consequences on biodiversity, ecosystem integrity, and the economy. In order to control invasive species, herbicides are used in natural areas where native plant abundance is a concern. Although, herbicides have been showed to adversely affect the germination non-target native plants. The extent to which soil characteristics, such as soil texture and duff depths, mitigate herbicide effects is unknown. I am proposing to assess the influence of soil factors on germination of the native plant species Gaillardia aristata (blanket flower) in soils that have been sprayed with herbicide. Specifically, I will set up a greenhouse experiment that includes treatment combinations of soil texture (sandy, clay, or silt soils) and duff thickness (no duff, 2 cm. duff, or 5 cm. duff). The pots will be treated with Milestone (active ingredient, aminopyralid), and then seeds will be planted in the pots. Germination will be measured after 5 weeks. The significance of this study is to inform restoration practitioners on how common herbicide use may impact non-target native plants in invasive species management.
Kendal Beauvais, University of Montana
2:40 PM - 3:00 PM
Although wildfire is a natural process in fire-adapted forests, it poses growing socioeconomic and health threats. Urban development and expansion into the wildland-urban interface (WUI) has heightened wildfire exposure, putting thousands of homes at risk in Montana alone.The Firewise USA program was created in an effort to reduce the risk of home ignition and loss in the WUI. The program encourages homeowners within WUI communities to engage in mitigation efforts such as using Firewise landscaping strategies to create a defensible zone around their homes and promotes the use of building materials that decrease overall ignition risk. Despite a growing body of literature about the effectiveness of Firewise mitigation strategies, there is a lack of knowledge about the best methods for educating homeowners; additionally, the factors preventing homeowner adoption of these behaviors are not well understood in the West. We are proposing to assess homeowners’ knowledge and usage of Firewise strategies, as well as evaluating whether knowledge and behaviors vary by demographic (age, income level, education, residence status, and previous experience of a fire event) through a social survey administered to homeowners in five neighborhoods located in the WUI in Missoula County, Montana. In addition to questions about knowledge and behaviors, it will include questions related to preferred methods of receiving information and education on Firewise strategies. Our findings can contribute to development of Firewise education and awareness programs in Missoula County, as well as creating a broader Firewise education in WUI communities across the country.
3:00 PM - 3:20 PM
A necessary objective of stream restoration is to establish willows along stream banks due to their role in bank stabilization, stream shading, and enhancement of biodiversity both within riparian zones and the stream channel. Since willows grow rapidly and spread clonally, their establishment can be an essential factor in the success of restoration projects. However, despite their importance, natural recruitment of willows is sometimes lacking after restoration. For example, we observed no natural willow recruitment on a stream restoration project in the Lolo National Forest (Montana) that involved installing beaver dam analogs, which mimic the pooling effects natural beaver structures have on streams in western watersheds. Although there is extensive literature on willows, there is limited information specifically on willow recruitment and growth post-restoration activities in riparian ecosystems. To fill this knowledge gap, we ask the questions: First, after BDA restoration, what is the rate of willow recruitment by root sprouts or seedlings and what is the abundance of willows in these restored sites? Also, To what extent are the environmental factors of water access, soil compaction, and abundance of competitor species impact the recruitment of willow? We will measure the density of willow by size class along streams in western Montana. We will then relate seedling density to measured environmental factors (soil compaction and water content) and the abundance of other competing plant species. We expect that willow germinant density will be negatively related to soil compaction and the presence of other vegetation competition and positively related to soil saturation. Our findings will contribute insight into the factors influencing willow recruitment and can be applied to develop practices to improve willow establishment and growth after restoration, which would create conditions that support wildlife and plant communities and connectivity within focal watersheds.
Mackenzie E. Weiland, The University Of Montana
3:20 PM - 3:40 PM
Amphibian populations around the world are declining at an alarming rate and the decline of western Montana amphibians reflects this trend. As part of the restoration monitoring efforts at Milltown State Park, MT, native amphibian occupancy should be measured. I chose Milltown State Park because it is the largest Superfund site in the U.S. and millions of dollars have been spent on restoration efforts since 2008. However, little is known about amphibian occupancy at the site. Currently, egg masses of the native Columbia spotted frog are found in permanent wetland sites at Milltown State Park, yet larvae detection at these sites was extremely low in the summer of 2021. I am proposing to determine whether predation by nonnative fish is the primary driver of the low larval recruitment. Specifically, I will count egg masses of Columbia spotted frogs (Rana luteiventris) in April to establish a baseline of breeding events at seasonal (fish-less) and permanent (fish-present) wetlands at Milltown State Park. Once eggs have had time to develop and hatch into larvae, I will conduct repeated catch-and-release sampling of larvae at both seasonal and permanent wetlands at the park. If I find fewer larvae in the permanent wetlands than in the seasonal wetlands, I will conclude that fish predation may be the primary driver of the differences in amphibian larvae detectability and recruitment. This mechanism would need to be tested in future studies, ideally in the lab and with field observations. If I do not find a significant difference in larval abundance between the seasonal and permanent wetlands, I will conclude that factors other than fish presence are limiting the recruitment of larvae (e.g. heavy metals, infectious disease, invertebrate predation, etc.). This research is important for assessing the success of the restoration project at Milltown State Park, with implications for further work that may be needed to improve native amphibian habitat. It has broader significance for the protection of native amphibian species in Montana.
Jacob D. Kleimann
3:40 PM - 4:00 PM
Drought-induced mortality is an increasingly important driver of forest loss across the western U.S. as the severity of drought intensifies under global climate change. Under drought, the water column in the xylem, the tree’s water transport system, encounters increasing tension, potentially leading to embolism and interruption of water transport. Repeated embolism can ultimately lead to hydraulic failure and eventual drought-induced mortality. Studies in poplar have shown that depletion of stored non-structural carbohydrates (NSC), which is common under drought, increases their vulnerability to xylem embolism. However, few studies have mechanistically characterized this relationship in conifer species or in naturally occurring field populations. Therefore, it remains unknown if NSCs play a functionally significant role in determining vulnerability to embolism and overall drought mortality risk. In this study, I will test whether NSCs influence vulnerability to embolism in naturally occurring Pinus ponderosa saplings. To test for an NSC effect, I will leverage an ongoing experiment where sapling NSC pools will be manipulated relative to controls (i.e. non-manipulated) by shading trees and simulating drought conditions. Vulnerability to embolism curves will be generated on branches from five trees per treatment using the air injection method: stems will be subjected to progressively increasing tensions to induce embolism, and at each tension I will measure the hydraulic conductivity. For each treatment, I will use NSC concentration data to test whether NSC depletion increases vulnerability to embolism based on vulnerability to embolism curves. This study will add to the literature on the dynamic roles of NSCs in regulating drought tolerance and may provide insights for advancements in modeling and predicting drought-induced mortality risk in forests.
Meredith C. Eiden, University of Montana, Missoula
4:00 PM - 4:20 PM
Zooplankton are microscopic organisms that are key components of aquatic ecosystems around the world. They represent an integral part of the food web and help transfer key nutrients such as carbon, nitrogen, and phosphorous from primary producers like phytoplankton to the invertebrates and fish that prey upon them. The diversity and composition of these organisms serves as a biological indicator of favorable conditions in aquatic environments and reflects ecosystem functioning or how much degradation has occurred. Understanding the zooplankton assemblage is a vital tool for restoration practitioners working in aquatic landscapes. Even though zooplankton are key components of aquatic food webs, they are often overlooked in restoration assessments. I will be comparing the zooplankton communities between the newly restored Missoula County Ponds and a natural reference pond in Lolo National Forest. I will use a 500-micron zooplankton net to sample each site once a month throughout May, June, and July of 2022. Learning how zooplankton richness and composition differ between formerly degraded sites and reference sites has the potential to enhance aquatic restoration implementation and recovery goals. This also presents an opportunity for practitioners and the public to become more informed on the importance of the microorganism assemblage in the broader food web and community recovery of aquatic ecosystems.
Fin A. Malone, University of Montana, Missoula
4:20 PM - 4:40 PM
As climate change increases drought severity in forested ecosystems, knowledge of hillslope-to-catchment scale ecohydrological processes is necessary to inform adequate conservation, restoration, and management. Drought impacts atmospheric demand and soil water availability, which are considered important drivers of plant growth and water stress. This soil-plant-atmosphere continuum (SPAC) characterizes the movement of water from the soil, through plants, and into the atmosphere. In mountain landscapes, gradients in elevation, aspect, and local topography may contribute to significant differences in SPAC and therefore vegetation response. Recent modeling of this system’s dynamics has become an important focus of ecohydrological studies. However, these studies are theoretical in nature. There has been limited field-based research to characterize how SPAC and tree growth may vary across complex mountain terrain. We are proposing to use observational data on soil moisture, atmospheric demand, and tree growth to observe SPAC patterns in time and space within a semiarid Montana watershed. Furthermore, a collection of soil samples and subsequent lab analysis will allow us to quantify SPAC and its spatiotemporal patterns at two hillslope sites, thus presenting a physical mechanism for the organization of plant growth across the landscape. As such, we hypothesize that hillslope position is a main driver of SPAC, and that timing and duration of tree growth is related to landscape patterns of SPAC. Our findings should contribute to critical understanding of landscape scale vegetation responses to changes in water availability and demand, important for addressing the ramifications of climate change.