Brandon Karcher

Live stakes are woody cuttings from wetland tree species that can root naturally when pounded into the ground. The use of live stakes in riparian and wetland restoration is becoming an increasingly popular technique because of its relatively low costs and maintenance requirements. However, the success of live stakes depends on species, environmental conditions, and planting conditions such as artificial rooting hormone or weed control strategies. The impact of such factors has not been widely studied, and much more research is available for western species and conditions than for those of eastern North America. We collected data in May 2020 using a common garden experiment with 1,550 stakes of nine native Pennsylvania species, where manipulated variables included the use of herbicide to control invasive species and rooting hormone to encourage root growth of stakes. Stakes were randomly blocked by species, and we examined what effect the use of herbicide, the use of rooting hormone, herbivory, presence of poison hemlock, species, stake diameter, and planting depth of stakes had on survival and number of buds produced. Our preliminary mixed effects model suggests that there is a positive relationship between stake diameter and number of buds and that when rooting hormone was used, stakes had more buds on average. It also suggests that most the species had similar high initial survival rates (>80%), except northern spicebush (57%), and that most species were consumed by herbivores at similar rates, except elderberry, which had more than twice the herbivory of any other species. When poison hemlock was present, stakes also had more buds on average. We hope to provide an analysis that will help conservation professionals gain insight into which local live stake species are most able to survive and quickly produce buds, and whether the use of rooting hormone or presence of poison hemlock impact survival or growth. Due to the global coronavirus pandemic, our site was not maintained this summer and is significantly overgrown. Therefore, we will repeat data collection in the coming months to identify which species are likely to have the greatest success at sites where maintenance is difficult or impossible.

Floods drive devastating climate-related disasters. These risks are expected to rise with environmental and
demographic changes. A sound understanding of dynamic flood hazards is crucial to inform the design and
implementation of flood risk management strategies. We develop a framework to assess riverine flood risks for
current and projected climate conditions. We implement the framework for rivers across the state of Pennsylvania,
United States. Our projections suggest that flood hazards across Pennsylvania are overall increasing with future
climate change. The analysis requires an integrated approach since the uncertainty in flood inundation
projections is impacted by uncertainties surrounding climate change, and hydrodynamic model structure and
parameter. We will discuss how this framework can provide regional and dynamic flood-hazard assessments and
help to inform the design of risk management strategies.

Chasmanthium latifolium (Poaceae) is a rhizomatous perennial plant species that lives in close proximity to rivers and streams, making it fittingly referred to as river oats. Native to the southern midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Chasmanthium latifolium (Poaceae) is comprised of two metapopulations that exhibit an east-west disjunction within Pennsylvania, one metapopulation around the Allegheny River, and one around the Susquehanna River. Due to the limited and isolated distribution of the species within the state, as well as declining populations, C. latifolium is considered a critically imperiled (S1) plant in Pennsylvania by the Pennsylvania Natural Heritage Program (PHNP) but is ranked as tentatively undetermined by the state. My study aims to achieve two main objectives: 1) investigate the genetic diversity and connectivity of the two metapopulations, and 2) revise the conservation status and develop scientifically informed policies to better conserve this species. This research utilizes a genotype-by-sequencing (GBS) approach to generate genomic data for use in population genetics analyses. By employing iPyrad and packages in the R statistical computing software to synthesize these data, I will gain insight into gene flow and the genetic stability of these metapopulations. Ultimately, my research will provide an updated, scientifically-backed conservation status assessment of C. latifolium in Pennsylvania. This project will combine rare plant survey protocols by the Pennsylvania Natural Heritage Program and Western Pennsylvania Conservancy and genetic work at Bucknell University to address broad conservation questions.

Warming stripes plots are a simple yet powerful way to convey large amounts of data. These plots show a series of bars filled with colors that represent annual temperatures, which allows clear communication of temperature changes throughout time. To date, air temperature data has most often been portrayed using warming stripes plots. I have adapted this concept to visualize water temperature data in rivers and streams. I acquired U.S. Geological Survey water temperature data across the U.S., comprised of >2.2 million observation from 224 stations across the U.S. that have been continuously monitoring water temperature for ≥10 years. These observations were summarized into mean annual temperature and presented in a website that allows users to view sites interactively on a map, and then view warming stripe plots of their choosing. The results demonstrate that although freshwater ecosystems are complex and dynamic, water temperatures are rising rapidly. This is consistent for watersheds in arctic and tropical climates alike. This presentation will provide an overview of the methods employed, a tutorial of the interactive website, and an invitation for those with additional data to contribute so that spatial coverage is enhanced. Currently, stations available within Pennsylvania are limited to the Delaware River watershed; datasets within the Susquehanna River are of significant interest.

If you are a landowner interested in installing conservation practices on your property, it can be daunting to figure out the full scope of options and who to contact to start this process. This challenge has been known to inhibit many individual property owners who own farms, woodlands, or residential property from pursuing conservation practices on their land, because the number of opportunities are overwhelming and a starting point is hard to identify.

Chesapeake Conservancy and American Farmland Trust have partnered to create a science-communication tool to summarize opportunities in an easy-to-digest printout for restoration practices specific to a landowner’s property. Restoration Reports.com is an easy-to-use online tool where a landowner can enter their address and management priorities, and receive a customized, understandable report of potential conservation and restoration practice options. Using high-resolution data and the latest geospatial technology, the Conservancy can tailor each report to the property level, and suggest appropriate points of contact for a landowner to get started. This presentation will discuss the challenge of reaching property owners in conservation and present a case study of how this tool was developed using GIS technology and applied to American Farmland Trust’s Women for the Land Initiative to reach women landowners and land managers. Restoration Reports is now available for landowners in nine Pennsylvania counties.

Aquatic insects have complex life cycles which often involve interactions with aquatic and terrestrial environments. Many insects rely on the presence of instream habitats, like riffles, to successfully complete multiple life stages. Riffles are particularly important for recruitment of insects that exclusively oviposit (lay eggs) on microhabitat like rocks or organic material. Riffles are also home to diverse larval communities that often serve as a source of individuals to proximal downstream habitat. We sought to investigate the extent to which instream habitat limits recruitment and community diversity of aquatic insects due to lack of suitable oviposition habitat and isolation of instream habitat patches.

To accomplish this, we constructed nine gravel and cobble riffles in a small central Pennsylvania stream previously lacking coarse inorganic and emergent substrate. These riffles were constructed in sets with different inter-riffle distances (15, 10, or 5 m) to determine if distance to upstream riffle and oviposition habitat affected downstream benthic invertebrate density. Benthic and drift samples were collected directly below each riffle and set of riffles every two weeks from September-October 2019. Riffles were also sampled for aquatic insect eggs, which were reared to adulthood in the lab. Composited Surber samples were also taken from constructed riffles and non-riffle habitat at the end of the experiment to compare community diversity between habitat types.

Initial results suggest that addition of emergent substrate increased insect recruitment to our stream, as 88% of egg masses were found on emergent rocks in riffles compared to 12% of egg masses on fully submerged rocks. Egg masses from Hydropsyche sp. (Trichoptera) and Chironomidae (Diptera) were found on both types of substrate, while Baetis sp. (Ephemeroptera) egg masses were only found on emergent rocks, which suggests that recruitment of taxa with selective oviposition behaviors could be limited by availability of emergent rock substrate. Additionally, larval insect densities were higher in reaches with riffles spaced 5 m apart (276.3 +/- 29.6) than in the control reach upstream of the constructed riffles (mean 113.7 +/- 7.6; ANOVA with Tukey’s pairwise comparison, p < 0.05). This study increased our knowledge of insect oviposition behavior and showed that providing oviposition and riffle habitat for aquatic insect taxa could improve recolonization and ecological recovery following restoration of habitat-limited streams. We suggest strategic riffle addition, including emergent substrate, as an augmentation of conventional structural restoration practices in streams.

Microblogging platforms provide an opportunity to reach audiences with a speed and scale much greater than traditional communication methods. They also present a vast source of publicly available data to analyze and identify successful or ineffective past practices in communication. Following the 2017 presidential inauguration ceremony, the active restriction of science communication by the Trump administration led to the creation of many unofficial and alternative, or “alt”, Twitter accounts for government agencies to maintain communication. Alt accounts quickly attracted many followers (e.g., 15 accounts with >100,000) and received a large amount of media attention. We analyzed tweets from paired “alt” and official U.S. government agency accounts to compare communication strategies and determine what elements of a tweet make it more likely to accrue attention (likes or shares). We found adding links, images, hashtags, and mentions, as well as expressing angry and annoying sentiments all increased retweets and likes. Evidence-based terms such as “peer-review” had high retweet rates; but linking directly to peer-reviewed publications decreased attention compared to popular science websites. Word choice and attention did not differ between account types, indicating topic was more important than source. The number of tweets generated, and attention received by, alt accounts rapidly decreased after the creation of these accounts, demonstrating the importance of timeliness in science communication on social media. Together our results show potential pathways for scientists to increase efficacy in social media communications.

The Clean Water Act regulates discharges of pollutants into streams and rivers, which includes point source discharges. This research aims to determine a framework for prioritizing best management practices (BMPs) and locations in urbanizing areas to fulfill the MS4 requirements. A list of criteria for BMP selection and placement was generated and GIS data consistent with the criteria were created to generate a spatial model identifying ideal BMP locations. Suitable locations for BMP’s are limited in river-towns such as Williamsport, PA. Working with local managers can improve models to help identify unintuitive locations for BMP locations, but overall prioritization systems are useful for MS4 regulated regions.

Federal regulations for municipal separate storm sewers (MS4) in the United States have been in place since 1990 as part of the Nation Pollutant Discharge Elimination System (NPDES), aiming to reduce sediment and pollutant loads originating from urban areas. However, small-municipality MS4 permittees frequently face several common challenges, barriers, and misunderstandings in their efforts to regulate stormwater. We summarize common challenges and misunderstandings concerning MS4 management and offer real-world examples of effective approaches for satisfying MS4 requirements. For example, many municipalities see no funding mechanism for implementing stormwater plans, and small municipalities are at a particular disadvantage in the absence of direct federal or state funding. Taxes are a potential mechanism yet often unpalatable to local municipalities. Grants or the creation of a stormwater utility can offset costs to local communities but also face barriers to implementation. Additionally, best management practices (BMPs) can improve stormwater quality but benefits to the local community from improved water quality are often poorly understood or mischaracterized. In spite of this, there are several MS4 management approaches that may be more approachable, including forming coalitions, forming stormwater utilities, and establishing monitoring programs. Small municipalities can benefit greatly from a realistic, facts-based clarification of MS4 policies and practices that lays out all of the options available to achieve NPDES requirements.