The effects of burning for oak savanna management on bumble bee community composition and abundance
Genevieve Pugesek, Department of Entomology, UW–Madison
This project will examine the hypothesis that spring prescribed fires used in management of oak savannas in southern Wisconsin have negative impacts on bumble bees. By sampling pairs of parcels within sites that are either burned or left unburned, we will evaluate bumble bee responses in two distinct phases of the life cycle. Early spring observations will focus on queen nest searching and flower foraging, and the habitat characteristics that are associated with burning. Midsummer sampling of workers will evaluate responses to burning during the colony growth phase and whether this is associated with differences in flower availability that may be influenced by burning. We further hypothesize that there will be differences in bumble bee responses to burning depending on their species-specific life history differences, such as nesting substrate preferences. This project will be part of a multi-year study in southern Wisconsin within the Great Lakes and adjacent Mississippi Watersheds with sampling starting in summer 2022. We will be working with local partners such as US Fish and Wildlife Service, Wisconsin Department of Natural Resources and the UW Arboretum to locate study sites. We expect that additional years of sampling will grow this dataset and subsequent years will expand the study design to include additional factors (e.g., landscape position, burn area) that could interact with burning to influence bumble bee responses.
Composition and change in vegetation in relation to the soil microbiome
Paul Zedler, Nelson Institute for Environmental Science, UW–Madison
There is increasing recognition of the importance of the soil microbiome as an element of ecosystem structure and function. Recent advances in biomolecular technology have made it possible to identify groups of microbes that correspond to what may informally be characterized as “species” and to assign these to functional groups. This allows the microbiome to be related to the plant community with which it is associated. An important application of this is to know if the restoration of the higher plant communities may be influenced by the microbial community that exists the soil, and if microbiomes in restorations converge of time towards those of undisturbed remnant communities.
The forgotten forest layer: Understanding the environmental drivers of understory woody shrub composition in mesic forests
Samuel Anderson, Department of Botany, UW–Madison
Advisor: Kate McCulloh
The deep shade found within the understories of mesic forests can drastically impede the ability of understory plants to persist, grow, and reproduce. The woody species characteristic of mesic forests of the Great Lakes Region have evolved to survive these photosynthetic constraints, although the factors shaping understory shrub composition are poorly understood. Tropical understory research supports the theory that species compete for light via various adaptations to maximize light capture, partitioning themselves along light gradients. Unfortunately, this theory has been scantily applied to temperate systems. My research consists of an observational field study and ordination of understory shrubs along gradients of light and soil texture in northern and southern mesic forests in Wisconsin to describe and quantify the niche space of some of Wisconsin’s most curious woody flora, including the potential niche competition and overlap between native and non-native shrub species.
Assessing the soil ecological stability of tree-associated microbiomes across a climatic gradient in Wisconsin
Zac Freedman, Department of Soil Science, UW–Madison
An improved understanding of the stability of plant-microbe associations across climatic gradients is imperative to understand how biological communities will respond to climate change and to improve predictions of future ecosystem carbon (C) storage (that is, with climate change, will C be stored in the soil as organic matter or in the atmosphere as CO2 and contribute to the greenhouse effect?) We propose for the UW–Madison Arboretum to serve as one of three sampling locations that create a north-south transect in Wisconsin that spans a natural climatic gradient in temperature, precipitation, and atmospheric N deposition. Soil samples will be taken beneath 2 tree species, one of which that associates with arbuscular mycorrhizal fungi like maple and one that associates with ectomycorrhizal fungi like oak. Soil samples will be analyzed to characterize microbial community composition, activity, and C and N cycling potential using techniques that are commonly used in PI Freedman’s lab.
Greenhouse gas dynamics and seasonal differences of water quality in stormwater ponds in Dane County, Wisconsin
Adrianna Gorsky, Center for Limnology, UW–Madison
Advisor: Emily Stanley and Hilary Dugan
Wet retention ponds are becoming more numerous as urban areas expand, and stormwater engineering practices are shifting toward slowing the flow of water off the landscape to enhance flood reduction and nutrient retention. The city of Madison, Wisconsin, and its surrounding suburbs is representative of many Midwestern landscapes that are influenced by both urban and agricultural stressors. We measured dissolved methane, carbon dioxide, and nitrous oxide concentrations in 20 small urban to suburban ponds in and around Madison during both the summer and ice-covered season. The goal is to better understand the drivers of gas production in ponds, which are increasingly being recognized as greenhouse gas hotspots. We expect the surrounding land use, pond age, morphological characteristics, and aquatic plant coverage to influence gas concentrations. Given the ubiquity of small, eutrophic water bodies regionally, our observations can better understand and quantify greenhouse gas production in temperate urban ponds.
Lost City Invasive Shrub Management
Tim Kuhman, Edgewood College
Brad Herrick and Christy Lowney, UW–Madison Arboretum
Invasive species are prevalent in southern Wisconsin. Landowners and managers allocate a lot of resources (time and money) into controlling invasive species. By studying management practices, including forestry mowing, forestry mowing followed by prescribed fire, hand clearing, and hand clearing followed by prescribed fire, we will be able to assess the efficacy of these management techniques for controlling woody invasive shrubs and allowing native herbaceous species to establish.