Do invasive species modify small mammal trophic interactions and generate predictable behavioral changes?

Carson Keller, Department of Integrative Biology, UW–Madison
Advisor: John Orrock

Invasive species dramatically alter ecosystems through the creation of novel habitat, competition, and consumption of native species, and generating reductions in biodiversity. Currently, there is limited understanding of how invasive-mediated ecological interactions generate indirect effects modifying trophic interactions. Using two invasive species, buckthorn (Rhamnus cathartica) and jumping worms (Amynthas spp), I will evaluate 1) if predictable suites of behaviors characterize the animals within invaded and uninvaded habitats, and 2) if these behaviors generate variation in rodent-worm interactions that promote biotic resistance or invasional meltdown. I will measure behaviors essential for individual survival, such as activity timing, boldness, stress physiology, and anti-predator behaviors. These behaviors will be measured using camera traps paired with seed depots, live trapping, and behavioral assays. Successful restoration and management may depend on quantifying the damage caused to native species and determining the factors leading to invasional success or failure.

Lake Wingra fall waterfowl migration survey

David Liebl, College of Engineering, Emeritus, UW–Madison

While the mallard duck (Anas platyrhynchos) and wood duck (Aix sponsa) are found on Lake Wingra throughout the open water season, another twenty-five species of migratory waterfowl have been observed on Lake Wingra in recent years. Using an intensive observation schedule, this project will track, record, and report species distribution and abundance of waterfowl on Lake Wingra during the fall 2020 migration season (October 1 through ice over).

Mycorrhizal colonization of oak phytometers in restored habitats

Yishai Barak, Department of Bacteriology, UW–Madison
Advisor: Anne Pringle

Mycorrhizal associations are an important mutualism to the success of plants. Fungal associates provide nutrients and protection from a variety of biotic and abiotic stresses to their plant host in exchange for photosynthetic carbon. In disturbed or eutrophic habitats, these associations can be disrupted. This study aims to discover if there is a gradient in mycorrhizal colonization across urban, restored, and natural settings within Dane County by using the native species bur oak (Quercus macrocarpa) as a phytometer. After one growing season the phytometers will be harvested and assessed for colonization.

Variation in plant defense

Phil Hahn, University of Florida

Intraspecific variation in floral phenotypes is a well-documented phenomenon across and within plant populations, and geographic variation has even been associated with entirely different pollinator guilds within species. Notable limitations in many of the current studies of this phenomenon, include disentangling the roles of phenotypic plasticity and non-pollinator species such as herbivores in mediating these variations. Defense against herbivory is another trait that may vary within species, and which may compromise attraction to pollinators, leading to evolutionary tradeoffs. The resource availability hypothesis posits that tradeoffs between defense against herbivory and plant growth occur across resource gradients between species, with defense being favored in low-resource environments and growth in high-resource environments, but does not address possible tradeoffs between defense and attraction of pollinators and does not necessarily address trends within species. We are addressing these ideas with common beebalm (Monarda fistulosa), a chemically defended entomophilous plant with a wide geographic range in North America, including both arid and mesic habitats.

Predicting restoration outcomes: land-use legacies, restoration methods, and management

Stephanie McFarlane, Botany Department, UW–Madison
Advisor: Ellen Damschen

Land-use intensification has resulted in a vast reduction of tallgrass prairie, and habitat restoration is critical for preventing the continued loss of plant and insect diversity. However, the mechanisms responsible for successful restoration are poorly understood. My research examines historical land-use legacies, restoration method, and fire management as three mechanisms known to affect outcomes in restored prairie communities. In 2018, 2019, and 2020, we conducted intensive vegetation sampling, collected floral resource data, and collected sweep samples at 36 restored tallgrass prairies throughout southern Wisconsin that are enrolled in the National Resource Conservation Service’s (NRCS) Wetland Reserve Easements (WRE). With these data we ask the following questions: 1) How does restoration method affect the restoration success in tallgrass prairie? 2) Does fire management interact with the restoration methods to influence success? 3) Does the quality of the prairie plant community or floral resource availability predict pollinator/insect abundance or community composition?

Mapping foliar drivers of ecosystem function

Phil Townsend, Forest & Wildlife Ecology Department, UW–Madison

Airborne hyperspectral imagery is being used to quantify and map plant functional traits for forests and grasslands in the UW Arboretum. We will quantify functional diversity and how functional traits vary over the course of the growing season. 1-m resolution hyperspectral imagery will be collected over the course of 2 growing seasons and will form the basis of analyses needed to prototype field calibration and validation for a planned NASA hyperspectral satellite later this decade.

Effect of Early Bird fertilizer on adult Amynthas earthworms

Brad Herrick and Marie Johnston, UW–Madison Arboretum

Asian pheretimoid earthworms of the genus Amynthas present an ongoing challenge for ecologists, land managers, horticulturalists, gardeners, and the green industry in general. These earthworms feed on organic matter, primarily in the form of leaf litter, and are commonly found in forests, gardens, mulched beds, potted plants, and other green products. Preliminary research and anecdotal observations suggest that theses earthworms eliminate the duff layer in forests, modify nutrient cycling processes, out compete or otherwise displace other earthworm species, and may negatively impact native and ornamental plant growth. Currently, there are no feasible control mechanisms to keep them from reproducing and spreading to other habitats. Early Bird, an organic nitrogen-based fertilizer, has been shown to significantly reduce earthworm casts on golf course putting greens. This study will test the efficacy of using Early Bird to reduce adult Amynthas numbers in a sugar maple forest.

Impacts of prescribed fire timing on oak (Quercus spp.) savanna restoration

Christy Lowney, UW–Madison Arboretum

Fire is essential for maintaining oak ecosystems and prescribed fire is a management tool commonly used to maintain oak systems in the absence of naturally occurring wildfires. The impacts of timing of prescribed fire in oak savanna restorations is an area where research is lacking. This study will examine the impacts of spring and summer prescribed burning, in varying rotations, on oak savanna restorations in Wisconsin and compare them to sites in Southern Michigan.