SFS Annual Meeting

6/05/2024  |   13:30 - 13:45   |  Salon 10

Contributions of Bald Cypress “Knees” to Greenhouse Gas Emissions in a Bottomland Hardwood Wetland Recent studies on wetland carbon emissions have focused on methane (CH4) fluxes from tree stems, while structures such as branches and exposed roots remain understudied. We are investigating the contribution of the exposed woody root structures (“knees”) of Bald cypress (Taxodium distichum) trees, a dominant bottomland hardwood wetland species in the southeastern United States, to carbon fluxes. Methane and carbon dioxide fluxes are being measured across microtopographic (i.e., lower and upper elevations) and climatic differences directly from individual knees, soils, and 1 m2 plots containing soils and knees. Despite varying environmental conditions, individual knees have continually acted as a CH4 source, even during a moderate-severe drought (Fall 2022), offsetting soil CH4 uptake during this period. A comparison of drought and non-drought years saw an increase in CH4 emissions from knees located in microtopographic lows. Similarly, during extreme flooding (July 2023), CH4 emissions increased only from knees in those same lows. We hypothesize this is due to the water table being closer to the rooting zone in those lows, allowing for the increased potential of knees to transport CH4 from the soil to the atmosphere. Work is ongoing to continue sampling these relationships, as well as relating flux rates to belowground porewater chemistry. These results highlight the importance of a holistic view of the entire tree’s role in carbon emissions, and potential influential factors, to create more accurate wetland carbon models.

Skylar Ross (Primary Presenter/Author), Murray State University, sross10@murraystate.edu;

Niklas Klauss (Co-Presenter/Co-Author), Murray State University, bassnik1111@gmail.com;

Jessica Moon (Co-Presenter/Co-Author), Murray State University, jmoon8@murraystate.edu;

Marissa Miles (Co-Presenter/Co-Author), Murray State University, mmiles6@murraystate.edu;

Kabiraj Khatiwada (Co-Presenter/Co-Author), University of Arkansas, kabik@uark.edu;

Bassil El Masri (Co-Presenter/Co-Author), Murray State University, belmasri@murraystate.edu;

Benjamin Runkle (Co-Presenter/Co-Author), University of Arkansas, brrunkle@uark.edu;

Gary Stinchcomb (Co-Presenter/Co-Author), University of Memphis, gstnchcm@memphis.edu;

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6/05/2024  |   13:45 - 14:00   |  Salon 10

PLANT COMMUNITY DEVELOPMENT AND THE ROLE OF ROOT-ASSOCIATED FUNGI IN YOUNG WETLANDS ON RECLAIMED AND REFERENCE LANDSCAPES OF THE ATHABASCA OIL SANDS REGION Open pit mining in the Alberta Oil Sands has disturbed over 1050 km2 (400 mi2) of land previously dominated by peatlands and boreal forest, which must be reclaimed to equivalent pre-disturbance land capability. Assessing the trajectory of young wetland development can provide insight on the efficacy of reclamation strategies. Reference wetlands of a similar post-disturbance age located outside the mine, offer a valuable comparison for identifying key stressors affecting the development of reclaimed wetlands. Plant community establishment and development in young wetlands may be facilitated by root-associated fungi (mycorrhizae and endophytes), but their role in wetland restoration is poorly understood. We assessed the plant community composition, landscape features, hydrology, soil and water chemistry of 80 wetlands (40 reclaimed, 40 reference) across a gradient of 2-40 years post-disturbance to identify patterns in young wetland development. Root-associated fungi present in soil and root samples from 18 reclaimed and 18 reference wetlands were identified using DNA sequencing. Preliminary results show high variability among environmental variables, plant and fungal communities, and between wetlands, with no distinct trends in post-disturbance age. Soil fungal communities correspond closely with wetland vegetation zones, with a greater richness of root-associated fungi found in the wet meadow zone compared to the emergent zone. Similar communities of plants and fungi were found on reclaimed and reference landscapes, suggesting that reclamation efforts have been relatively successful considering the young age of the landscape. This research contributes to the growing body of knowledge contributing to the assessment of reclaimed and young boreal wetlands.

Elizabeth Gillis (Primary Presenter/Author), University of Calgary, elizabeth.gillis@ucalgary.ca;

Ashlee Mombourquette (Co-Presenter/Co-Author), University of Calgary, ashlee.mombourquette@ucalgary.ca;

Montserrat Villegas Torres (Co-Presenter/Co-Author), University of Calgary, montserrat.torres@ucalgary.ca;

Hannah Porter (Co-Presenter/Co-Author), University of Calgary, hannah.porter@ucalgary.ca;

Maeve Corcoran (Co-Presenter/Co-Author), University of Calgary, maeve.corcoran@ucalgary.ca;

Hunter Jackson (Co-Presenter/Co-Author), University of Calgary, hunter.jackson@ucalgary.ca;

Peter Dunfield (Co-Presenter/Co-Author), University of Calgary, pfdunfie@ucalgary.ca;

Jan Ciborowski (Co-Presenter/Co-Author), University of Calgary, jan.ciborowski@ucalgary.ca;

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6/05/2024  |   14:00 - 14:15   |  Salon 10

The Effects of Road Salts on Vegetation Communities in a Large Freshwater Wetland in Southeastern Pennsylvania The application of deicing salts to roadways poses risks to freshwater systems on landscape scales by degrading water and soil quality. However, the documented impacts of road deicing salts on freshwater emergent wetland vegetation communities vary. Understanding how human activities impact wetland ecosystem services and habitats is increasingly important, especially in headwater systems. This study explores the effects of road deicing compounds on the freshwater vegetation communities in the largest contiguous freshwater wetland complex in Southeastern Pennsylvania along its interface with Interstate 76. Along five linear transects running perpendicular to the marsh-interstate interface, shallow groundwater quality was monitored periodically over the course of a year and vegetation community composition and soil parameters were measured during the peak growing season. We quantified concentrations of chloride and sodium ions (common deicing salts) within the shallow groundwater and soils and compared these to the vegetation diversity indices such as species richness in the study area. As predicted, our results suggest that shallow groundwater collected closer to the marsh-interstate interface showcase higher and more variable electrical conductivity (mean = 2,096 µS/cm, SD=1,843) than groundwater sampled further from the interstate (mean = 436 µS/cm, SD = 146). While patterns in vegetation are less clear, results suggest that communities near the interstate are more likely to be dominated by invasive species and have lower species richness. The results of this study can be used to inform local and regional watershed conservation planning and mitigating impacts to critical freshwater wetlands threatened by anthropogenic salinization.

Benjamin Langey (Primary Presenter/Author), West Chester University of Pennsylvania, bl1001394@wcupa.edu;

Megan Fork (Co-Presenter/Co-Author), West Chester University, mfork@wcupa.edu;

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6/05/2024  |   14:15 - 14:30   |  Salon 10

Can variability in microbial habitat distribution alter net methane emissions? Soil microbial habitats can vary in their level of complexity. Few studies have documented whether this habitat complexity matters to net ecosystem function. Scale transition theory has been used to explain how spatial and temporal variation can interact with the nonlinear dynamics of organisms and communities, leading to inaccuracies when using linear averaging to make larger-scale predictions. Using hydric soil mesocosms, we investigated whether spatial resource patterning affects net methane emissions. In our first trial, we compared net emissions and microbial communities across inundated mesocosms with three treatments: without bald cypress needles, with needles clumped into one patch, and with evenly distributed needle patches (n=3 each). During initial decomposition, we found the highest mass loss of needles in the distributed treatment but higher emissions in the clumped treatment. Emissions were only statistically different between the clumped and no-needle treatments. This may be the result of our small sample size with high natural variation of hydric soils or due to the mobility of resources during initial decomposition. Ratios of methanotrophs to methanogens were higher in samples collected further from needle patches than those adjacent to needles in the distributed treatment but did not differ based on distance from needles in the clumped treatment. We are beginning a second trial and have hypothesized that while clumped distributions may lead to lower rates of methanogenesis, they also may lead to clumped distributions of methane, limiting methanotrophic activity and leading to higher net emissions.

Jessica Moon (Primary Presenter/Author), Murray State University, jmoon8@murraystate.edu;

Isaiah Radford (Co-Presenter/Co-Author), Murray State University, iradford@murraystate.edu;

Karen Baumann (Co-Presenter/Co-Author), Murray State University, kbaumann1@murraystate.edu;

Michael Flinn (Co-Presenter/Co-Author), Murray State University, mflinn@murraystate.edu;

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6/05/2024  |   14:30 - 14:45   |  Salon 10

Maine’s Secret Clam Flats: The Aquatic Diversity of Northern White-Cedar Forests Northern white-cedar lowlands in Maine are forest habitats that are frequently managed as conventional timberlands; the aquatic biota and processes present within them are often overlooked. Although these forests may appear dry during harvest periods, recent data have shown they can remain wetted in localized depressions (‘pits’) throughout the year and at times much of the forest may be flooded. There remains a gap in the literature as to what types of aquatic biodiversity and processes these forests support and how those are impacted by forest management practices. Our research encompasses harvested and control stands in three working northern white-cedar forestlands in Maine. The goal of this research is to expand our understanding of the intermittent nature and biological processes of these forested wetland habitats, with specific objectives to: 1) compare invertebrate biodiversity, assemblages, and biomass between harvested and control lowland northern white-cedar sites; 2) determine how rates of aquatic leaf litter processing vary between pit and mound microclimates; 3) develop methods for assessing invertebrate biodiversity and wetland processes in a way that can inform northern white-cedar harvest management and be expanded to other northeastern lowland forests. Preliminary findings show that fingernail clams frequently dominate the aquatic macroinvertebrate communities, appearing in the majority of sampling locations (92%). Our work aims to inform managers of the biodiversity and processes that drive habitat functioning and to provide a basis for further research on the intermittent aquatic ecosystems of northern white-cedar lowlands.

Stevie Benson (Primary Presenter/Author,Co-Presenter/Co-Author), Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, Maine, USA, stevie.benson@maine.edu;

Christina A. Murphy (Co-Presenter/Co-Author), U.S. Geological Survey, Maine Cooperative Fish and Wildlife Research Unit, Orono, ME, christina.murphy@maine.edu;

Noah Charney (Co-Presenter/Co-Author), Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, Maine, USA, noah.charney@maine.edu;

Sue Eggert (Co-Presenter/Co-Author), U.S. Forest Service, Northern Research Station, Grand Rapids, Minnesota, USA, susan.eggert@usda.gov;

Shawn Fraver (Co-Presenter/Co-Author), School of Forest Resources, University of Maine, Orono, Maine, USA, shawn.fraver@maine.edu;

Laura Kenefic (Co-Presenter/Co-Author), U.S. Forest Service, Northern Research Station, Bradley, Maine, USA , laura.kenefic@usda.gov;

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6/05/2024  |   14:45 - 15:00   |  Salon 10

Combining joint species distribution modelling and isotope analysis to test the generalist module hypothesis in a lake-floodplain meta-ecosystem Meta-ecosystems comprise coupled ecosystems that exchange matter and energy via the movement of organisms. The generalist module hypothesis (GMH) posits that large organisms are responsible for such coupling, as relatively larger species tend to be more mobile than smaller species. Here, we test the GMH by studying how fish communities is size structured and witch functional traits is characteristic of there presence in fluvial Lake Saint Pierre (Quebec, Canada) and its floodplain. A joint species distribution model linking the functional traits of fish species to their habitat use (lake, floodplain or both) revealed that species found in both habitats are not larger species with great mobility, but are smaller species with early reproduction. Isotopic analysis confirmed that species with a higher probability of occurrence to be further away on the floodplain have a ?13C isotopic signature associated with allochthonous resources, and thus that the movement of these species back into the lake could represent a floodplain-to-lake subsidy. Again, contrary to the GMH, a ?13C signature indicative of allochthonous resources was associated with a smaller body size and with a lower trophic level (measured with ?15N). Combined, these results suggest that the generalist module hypothesis does not hold in a temperate lake-floodplain meta-ecosystem where the exploitation of the floodplain habitat might be more constrained by the phenological traits of species (reproduction time) than by their motility.

Thibaud Tournadre (Primary Presenter/Author), UQTR, thibaud.tournadre@gmail.com;

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