Current Fellows
_Iriart_headshot_web_200_150_s_c1.jpg)
Veronica (Vero) Iriart
University of Pittsburgh (Pennsylvania)
Will Herbicide Pollution Cost Plants Their Mutualisms with Pollinators and Soil Bacteria?
In 1962, scientist Rachel Carson from Pittsburgh sounded the alarm for greater environmental responsibility through her book Silent Spring. What followed was revolutionary change in the law, most famously the ban of the pesticide DDT which was inadvertently decimating bird populations across the country. Despite these achievements, chemical pollution from pesticides is still a significant environmental concern today. In particular, herbicide drift, which occurs when herbicide particles are taken up by the wind unto nontarget areas, is on the rise due to the increasing popularity of potent yet drift-prone herbicides. My previous work and that of others has shown that herbicide drift exposure can disrupt mutualisms (ecological interactions in which both species benefit), especially those between wild plant, pollinator (mainly bees), and beneficial bacteria species. However, the long-term consequences of herbicide drift pollution are unknown, such as whether it could cause these mutualisms to ultimately breakdown over the course of evolution. This year, my research will use a combination of greenhouse and field studies at the University of Pittsburgh, Oakland Campus and the Hilltop Urban Farm in the St. Clair neighborhood of Pittsburgh to confront the challenge of predicting evolutionary outcomes of herbicide pollution on the plant-pollinator and plant-bacteria mutualism, which together produce one-third of all food outputs and improve soil quality worldwide. As a result, this research will provide important insights into the threats facing natural systems upon which we all depend, and thereby help support their conservation.
Research Advisor: Dr. Tia-Lynn Ashman, Distinguished Professor, University of Pittsburgh

Sarah Klionsky
University of Connecticut (Connecticut)
Influence of Plant Community Traits and Microtopography on Nitrogen Removal in Restored Wetlands on Former Cranberry Bogs
Rivers transport nitrogen from human activities, such as fertilizer use, wastewater disposal, and burning fossil fuels, to coastal estuaries where it causes changes to the environment and negatively impacts aquatic organisms. Many municipalities are looking for “nature-based solutions” to help remove nitrogen from watersheds before it reaches the coast. Wetlands have the potential to remove a lot of nitrogen from river systems, because saturated conditions are necessary for an essential step of the process, denitrification, to occur. Restoring wetlands on former agricultural land is a strategy for increasing the amount of wetland area in a watershed. The restored wetlands that I will study are retired cranberry farms, or bogs, in southern New England that have been actively restored to re-establish wetland conditions. Plants play an important role in creating conditions favorable to denitrification. Wetlands often have local differences in topography, called microtopography, which promote a more varied plant community and impact the conditions that are beneficial for denitrification. I will study the relationship between wetland nitrogen removal, the plant community, and microtopography by surveying plants and collecting plants and soil at different elevations for laboratory analyses. This research will both help us learn more about the factors that contribute to denitrification and inform future wetland restoration projects. I will also create a virtual field trip and related experiential activities to introduce students to plant-based ecosystem services on restored wetlands.
Research Advisor: Dr. Beth Lawrence, Assistant Professor, University of Connecticut

Haley Lewis
Northwestern University (Illionis)
Green is the New Grey: Designing Green Infrastructure Networks to Improve Stormwater Management and Enhance Biodiversity
The US landscape has drastically shifted from natural areas with the ability to contain large storms and prevent flooding to overpopulated cities covered by impervious surfaces. This reduction in natural ground cover is associated with more frequent flood events, and as climate change continues to threaten the frequency and magnitude of storm events, it is important that we implement methods to prevent possible disasters to our existing infrastructure and ways of living. Green infrastructure integrates ecological benefits into existing built infrastructure to help mitigate potential disasters like extreme storms and subsequent flooding. Rain gardens are a type of GI that are typically engineered to divert, pool, and slowly soak incoming rain from an impervious surface such as a roof or a nearby street. In this study, we will study 9 rain gardens in the Evanston, Illinois and Pittsburgh, Pennsylvania to understand GI performance for water storage, water quality improvement, and biodiversity enhancement influenced by vegetation, soil quality, stormwater source & contaminant loading. For instance, does it matter what the plants are – or is GI performance influenced by what the plants are, how important is maintenance, and is vegetation quality and quantity influenced by soil quality and pollutant loading? We will accomplish this by surveying vegetation, analyzing soil and water samples, and equipping our rain gardens with a network of sensors to determine the water balance. Ultimately, we hope this data will be used to help create models that will be implemented in GI design plans for communities experiencing extreme flooding.
Research Advisor: Dr. Kimberly Gray, Northwestern University

Florencia Deyanira Pech-Cárdenas
University of Minnesota (Minnesota)
Handicraft Production Influences on Gender, Livelihoods and Natural Resources Management in Maya Communities: TEK of Chakaj (Bursera simaruba) and Forest Governance
Tourism around cultural/heritage sites has opened up opportunities for local communities to sell handicrafts worldwide. However, negative impacts such as forest deforestation and exclusion of women from full participation, are often overlooked in Indigenous communities which depend on direct extraction of natural resources to produce such handicrafts. Confronting these issues proves important for developing sustainable tourism practices, and for facilitating handicraft production based on sustainable management of the forest. In this research, I explore the social and environmental impacts of handicraft production driven by the tourism market at Chichén Itza, Yucatan, Mexico. In this research, I analyze the social and environmental impacts of handicraft production driven by heritage tourism upon livelihoods and natural resources management of Maya communities close to the World Heritage Site of Chichén Itzá in Yucatán, México. First, I will explore the ethnobotanical aspects of chakaj (Bursera simaruba), which is harvested by Maya artisans from their community forests for the wooden handicraft production. I also explore how chakaj populations in the forest are being influenced by handicraft production harvests. Second, I focus on the social effects by analyzing the motivations, challenges, and modes of organization of handicraft production from a Maya artisan perspective. Third, I explore the roles of handicraft production in indigenous women’s lives. Finally, I investigate the implications of handicraft production on forest management and communal land use policy at a local level. My project addresses urgent challenges for achieving sustainable forest management, sustainable tourism, and indigenous peoples’ autonomy.
Research Advisors: Dr. Kristen C. Nelson, Professor, H.T. Morse Distinguished Faculty, University of Minnesota, and Dr. Mike Dockry, Assistant Professor, University of Minnesota

Amanda Thiel
Washington State University (Washington)
Medical Botanical Knowledge Conservation amidst Globalizing Forces in
Mayan Communities of Southern Mexico
Around the world there is a general sense that indigenous knowledge — especially knowledge of the environment — is being lost as cultures globalize. Knowledge of plants, in particular, is important because it has allowed humans to survive — providing food, shelter and medicine — throughout history. This research examines how cultural knowledge varies to identify risks and preservation strategies for plant-related medical knowledge in two Maya communities of varying urbanization in southern Mexico. By assessing differences in cultural knowledge and values we can better understand and conserve endangered ethnobotanical knowledge and shed light on the impacts of urbanization and globalization on botanical traditions. The Maya area is an ideal place for this investigation because millions of people maintain centuries-long plant-use traditions, yet globalization is transforming rural life-ways.
Research Advisor: Dr. Marsha Bogar Quinlan, Associate Professor, Washington State University

Emily C. Thyroff
University of Hawai‘i at Mānoa (Hawai‘i)
A Key to Restoring Threatened Hawaiian Dry Forests Resides with the Endemic Santalum Species
Hawaiian sandalwood, locally known as ‘iliahi, serve many roles in native forests, from stabilizing soil, to medicinal properties, producing valuable oils, and supporting endangered bird species. ‘Iliahi also lives in harmony with native Hawaiian plants, though it has a unique relationship with its neighbors. ‘Iliahi needs to connect its roots with neighboring plants to survive; therefore, ‘iliahi need a healthy forest community to thrive. Extensive, unregulated removal of native species in Hawaiian dry forests where ‘iliahi reside, severely reduced numbers of native species, especially ‘iliahi. To effectively restore and conserve ‘iliahi, we also need to restore and conserve neighboring plants. This proposal focuses on one part of a larger project aiming to improve the survival and early growth of planted ‘iliahi seedlings by better understanding its distinctive relationship with other plants. Specifically, this project will pair ʻiliahi with four native dry forest plants. We will measure plant growth and development to determine which native plants best support ʻiliahi. We hypothesize that nitrogen use, growth rate, and fertilizer and water amounts will influence how well the native plants can support ʻiliahi. Results from this project contribute to our understanding of plants that require the support and root networks of other plants. We hope to improve active healing, forest restoration, and conservation efforts by giving Hawaiian communities confidence in establishing healthy, thriving forest communities.
Public Abstract – Hawaiʻi Audience*
*Since moving in August 2019 (I’m originally from western New York and have lived in several states) to Hawaiʻi for my Ph.D. program I have learned how unique the islands are and how important incorporating the language is. Therefore, I included this third abstract which is more insightful to what I will share locally for a public Hawaiʻi audience. Some Hawaiian words are included, but the context should help Hawaiians and visitors alike who may not be as familiar with the indigenous language.
‘Iliahi (Hawaiian sandalwood) hold many kuleana in native forests, from stabilizing soil, to medicinal properties, producing valuable oils, and supporting endangered bird species. ‘Iliahi also lives in lōkahi with native Hawaiian plants, though it has unique pilina with its neighbors. ‘Iliahi needs to connect its roots with neighboring plants to survive, and therefore ‘iliahi need a healthy forest community to thrive. Extensive, unregulated removal of native species in Hawaiian dry forests, where ‘iliahi reside, severely reduced numbers of native species, especially ‘iliahi. In order to effectively conserve and mālama ‘iliahi to become more momona again, we also need to conserve and mālama neighboring plants too. This proposal focuses on one part of a larger project aiming to improve the survival and early growth of planted ‘iliahi seedlings by better understanding its pilina with other native plants. Specifically, this project will pair ʻiliahi with four native dry forest plants. We will measure plant growth and development to determine which native plants best support ʻiliahi. We hypothesize that nitrogen use, growth rate, and fertilizer and water amounts will influence how well the native plants can support ʻiliahi. Results from this project contribute to our ʻike of plants that require the support and root networks of other plants. We hope to improve active healing, restoration, and conservation efforts by giving each other confidence in establishing functionally compatible forests and robust native plant communities.
Research Advisor: Dr. Travis W. Idol, Professor of Tropical Forestry and Agroforestry, University of Hawai‘i Mānoa

Alexa S. Wagner
Case Western Reserve University (Ohio)
Understanding the Impacts of Forest Restoration on Demographic Shifts in the Understory Plant Community
The abandonment of agricultural lands is common in the United States. As forests regenerate on these degraded landscapes, the resultant forests tend to have fewer species and trees that grow more slowly than do old-growth forests. In part, these changes are driven by invasive species, originating from other parts of the world and establishing in these new-growth forests. These novel species can suppress or displace the native plants important for ecosystem health and functioning. In these new forests, trees tend to establish at the same time and mature at similar rates, creating dense, evenly-aged stands in contrast to original old-growth forests which have greater diversity of mixed-age native plants. To restore the historic integrity of these forests, forest managers implement removal of invasive plants while thinning dense tree stands through timbering. However, we lack a full understanding of how these efforts impact the health and diversity of these restored forests. My research explores how proper forest management creates resilient forests. During my graduate studies, I am quantifying the impacts of forest management on the growth, survival, herbivory, and dispersal of native and invasive plants. This research will inform best management practices, improving our ability to manage and restore our young forests. Using my connection with the Holden Arboretum, I will use this information to help influence the forest management decisions of landowners regionally, and beyond.
Research Advisor: Dr. Katharine L. Stuble, Holden Arboretum and Case Western Reserve University

Taylor Zallek
University of Pittsburgh (Pennsylvania)
Understanding How Community Evolution to Invasive Species Impacts Future Invasion Success
Biological invasions occur when populations of organisms are transported beyond their home range to new areas where they thrive and become successful over time. Scientists have long wondered why some organisms successfully invade while others do not. Many researchers consider the qualities that make a species good at invading, while some consider the qualities that make the communities and environments they invade good at preventing or resisting invasions by these new species. One attribute of communities that is often overlooked is how the change in genetic composition of community members over time (i.e. evolution) might help or hinder the community’s ability to resist invasion. I plan to address this by studying how populations of small floating aquatic plants called duckweed evolve in response to an invasive aquatic plant called Salvinia. First, I will expose populations of duckweed to either the presence or absence of Salvinia and allow them to grow, compete, flourish, or die for nine weeks. I will then take these same populations of duckweed and expose them to Salvinia once more to see if the prior evolution to the invader changed how these communities respond. This change will be measured by comparing the Salvinia growth within communities that have or have not evolved alongside the invader. This research will help us to better understand how could impact the conservation of aquatic plant communities and beyond.
Research Advisor: Dr. Martin Turcotte, Assistant Professor, University of Pittsburgh
Top photo © Paul g. Wiegman