RESEARCH

Plant Community Change, Rare Plant Population Dynamics, Ecological Monitoring

DYNAMICS IN COASTAL DUNE VEGETATION

In collaboration with the National Park Service, in 2014 we implemented a revised protocol for surveying beach and dune vegetation on sandscapes in the Apostle Islands National Lakeshore. We resurveyed these 14 sandscapes in summer 2023. The primary aim of our work is to detect declining vegetation in this rare coastal ecosystem in western Lake Superior and, if warranted, to assist park managers with identifying management strategies. More extreme water-levels and storms may continue to influence coastal habitats in the Great Lakes, so we are also interested in identifying biodiversity and structural shifts in vegetation across periods of water-level extremes. Further, In collaboration with landscape ecologist, Dr. Monika Shea, we are applying spatial analyses of geomorphological changes in this dynamic coastal habitat in response to an extreme water level rise in Lake Superior.

RARE PLANT ECOLOGY AND MONITORING

Lake Superior Islands: In collaboration with the National Park Service, Sarah has studied population dynamics of rare arctic/alpine disjunct plant species in Isle Royale National Park and the Apostle Islands National Lakeshore in Lake Superior, including state endangered, threatened, and special concern species in Michigan and Wisconsin. Many of these rare species occupy rocky shoreline habitats.

Atlantic Coast: Sarah studied the ecology and population dynamics of the Federally Threatened seabeach amaranth (Amaranthus pumilus) in Cape Hatteras and Cape Lookout National Seashores on the Atlantic Coast. She conducted a greenhouse experiment to study the influence of competition on survival and growth of this rare annual plant, as well as contributed to field experiments that assessed transplant success at different elevations on the beach.

FOREST COMMUNITY CHANGE

Plant Watch! Monitoring changes in the spring and summer flora of northern hardwood forests: In summers 2022/23, our research team re-established the long-term 'Plant Watch' plots established in Northern Hardwood forests in the Penokees region of northern Wisconsin in the mid-1990s by Dr. Jim Meeker. Our work was funded by the US Forest Service and is truly a multi-generation Northland College project that supported dozens of students 1996-2000 and again in summers 2022 and 2023. Our data includes vegetation surveys in both spring and summer across multiple sites, providing us with a relatively unique opportunity to track changes in spring ephemerals, which most long-term monitoring data sets miss. Many NC alumni who worked on this project continue to work as professional botanists, ecologists, or other related careers (such as creating beautiful botany-inspired art). Sarah and her students have enjoyed collaborating with Plant Watch alumn, Dr. Kate Miller (quantitative plant ecologist with NPS) on statistical analyses, and with botanists at the Chequamegon National Forest.

Growing Capacity for Species Conservation: Biodiversity in northern hardwood forests in the Great Lakes region is declining, as demonstrated in our Plant Watch monitoring project. In collaboration with botanists of the Chequamegon National Forest, we initiated a project in 2024 to grow native plants in Northland College's greenhouse. Sarah developed a 1-credit course called Seed Biology & Use in Restoration and students collected and cleaned seeds for use in this project. Students in her Restoration Ecology course in winter 2025 will grow these native plants in the greenhouse and in the spring students will help USFS staff plant seedlings to diversify pollinator habitat in the national forest.

Plant Ecology Laboratory of UW-Madison - Biodiversity change in Wisconsin forests: Sarah studies long-term change in the forest herb layer in the Great Lakes region. Using an historic data set collected by students of Dr. John Curtis in the 1950s (author of the classic book, The Vegetation of Wisconsin), Sarah has collaborated for several years with other scientists on studying biodiversity changes in Wisconsin's vegetation. Her dissertation focused on half-century changes (1950s to 2007/08) in the understory and canopy of floodplain forests and hardwood swamp forests of southern Wisconsin. She contributed significantly to building the initial functional trait database used to compile an extensive set of trait data for hundreds of Wisconsin's plant species, and she also contributed to the study of half-century changes in vegetation of upland forests in the Apostle Islands.

Ecological Monitoring in Great Lakes Forests (Great Lakes I&M Network, National Park Service): In collaboration with staff of the Great Lakes Inventory & Monitoring Network of the National Park Service, Dr. Erika Mudrak, and Dr. Don Waller, Sarah led a field crew in Pictured Rocks National Lakeshore and Apostle Islands National Lakeshore to compare field methods to co-develop a forest vegetation monitoring protocol that is now applied across nine Great Lakes region National Parks.

COASTAL WETLAND COMMUNITY CHANGE

Monitoring coastal peatlands in the Apostle Islands: Using a long-term data set established in the 1990s by Dr. Jim Meeker, we resurveyed coastal and inland wetlands in the Apostle Islands National Lakeshore in 2017 to assess vegetation response to falling and rising water levels in Lake Superior. In collaboration with Dr. Matt Cooper (Burke Center for Freshwater Innovation), we incorporated our findings into a broader assessment of climate change vulnerability and adaptive capacity of the flora and fauna of these unique coastal wetlands.

Monitoring coastal wetland vegetation in a Ramsar Wetland of International Importance: In collaboration with the Mashkiiziibii Natural Resources department, we are contributing to long-term monitoring of the diverse and culturally important coastal wetlands of the Kakagon and Bad River Sloughs. Designated as Ramsar wetlands of international importance, these wetlands include extensive wild rice beds and are of critical regional importance to the Bad River Tribe.

Monitoring non-native cattail expansion in coastal wetlands: In collaboration with the Mashkiiziibii Natural Resources department and the late Dr. Jim Meeker, we used long-term monitoring plots to study the rate of non-native cattail (Typha x glauca, T. angustifolia) invasion and the impacts to native wetland communities in the Bad River and Kakagon Sloughs.

POPULATION DYNAMICS OF EVERGREEN CONIFER SHRUBS

Canada Yew Project: Using long-term data collected by Emmet Judziewicz in the 1990s, we resurveyed the forest understory across the majority of islands in the Apostle Islands National Lakeshore to assess changes in the distribution and status of Canada yew (Taxus canadensis).

Juniper Project: In collaboration with the National Park Service, we mapped and assessed the health and possible causes for decline in common juniper (Juniperus communis) on dunes in the Apostle Islands National Lakeshore.

HERBIVORY IMPACTS TO FOREST VEGETATION

In collaboration with Dr. Jill Witt (Lake Superior State University) and Dr. Don Waller, Sarah is assisting with a long-term exclosure study of deer impacts to vegetation in the Upper Peninsula of Michigan at the Huron Mountain Club near Lake Superior and in Cedarville, MI on the shores of Lake Huron. We established an efficient method to assess deer browse impacts by ageing twigs.

FIRE HISTORY IN GREAT LAKES MARITIME FORESTS

In collaboration with Dr. Jon Martin, we assessed vegetation response in known locations of historic fires caused by lightning strikes in wet-mesic to mesic maritime forests in the Apostle Islands National Lakesore. We assessed the response of Canada yew (Taxus canadensis) to recent and charcoal-dated older fires. (Photo: J. Martin)