Dr. Andrew Baldwin is a Professor of Wetland Ecology and serves as Director of Undergraduate Programs for the Department of Environmental Science and Technology. He became interested in plants as a teenager, adopting his Mother’s love of plants and natural history, and maintained this interest through college, where he received double degrees in engineering and biology. After college he worked as an environmental engineer and wetland ecologist in several positions. He returned to graduate school to study Botany in Louisiana delta plain wetlands, and shortly after graduation started as a professor at University of Maryland.
Currently, Dr. Baldwin directs an active research program in wetland plant and ecosystem ecology, supervises graduate students, teaches courses on wetland ecology and restoration, serves on university committees, and provides peer reviews on behalf of refereed journals and granting agencies. In his role as director of undergraduate programs, he has overseen the development and periodic revision of the ENST undergraduate curriculum.
The majority of research in the Baldwin lab focuses on coastal and restored wetland ecosystems. An active collaboration with Dr. Stephanie Yarwood and her research group focuses on plant-microbe interactions in coastal wetlands. Specific questions concern effects of plant species on bacterial, archaeal, and mycorrhizal communities; effects of organic material amendments in establishment of microbial communities and their associated ecosystem functions in restored wetlands; and the role of mycorrhizae and nitrogen availability in the restoration of the native lineage of Phragmites australis, and how these factors may control growth of the invasive lineage. Another active project is examining variable and practices affecting the restoration of wetland plant communities and ecosystem services in Delmarva Bay wetlands as part of USDA’s Conservation Effects Assessment Project. Another active project, funded by NOAA, seeks to integrate ecological and socioeconomic sciences to promote restoration of coastal marshes and increase resilience of coastal communities. This projects is a collaboration with Dr. Brian Needelman, other University of Maryland faculty, and government staff.
Field sampling of native and invasive Phragmites australis at the Choptank River, Maryland. In the background, the shorter stand on the left is native Phragmites, and the taller stand on the right is Invasive Phragmites.
Pooled water and buttressed tree trunk in a Delmarva Bay isolated depressional wetland.
Forecasting the response of tidal freshwater marshes to increasing salinity and higher tides due to sea level rise
While it is generally accepted that coastal wetlands worldwide are threatened by increases in sea level, most research to date has focused on salt and brackish marshes. Little is known about the current status of tidal freshwater marshes or how these diverse and productive wetlands may respond to increases in water level and salinity due to rising sea level. The overall goal of this research is to understand responses of tidal freshwater marshes to sea level rise.
Toward meeting this goal we have established a series of study sites in wetlands along the tidal portion of the Nanticoke River, a subestuary of Chesapeake Bay that extends from Maryland into Delaware. At these sites we have set up Surface Elevation Tables (SET) for measuring elevation changes and feldspar Marker Horizons (MH) for measuring vertical accretion. From these measurements we are able to determine if wetlands along the tidal fresh to brackish gradient of the Nanticoke are accreting and building elevation at a sufficient rate to keep pace with rising sea level.
In a related study we simulated saltwater intrusion into tidal freshwater marshes by applying synthetic sea water solutions and measuring elevation and accretion changes using replicate SET-MH stations. This research was conducted in tidal freshwater marshes at Jug Bay on the Patuxent River in Maryland.
This research is funded by the Department of Energy’s National Institute for Climatic Change Research.
Measuring wetland surface Location of SET-MH study sites elevation change using the (yellow markers), Nanticoke River, Surface Elevation Table (SET). Maryland and Delaware.
Grazing as a means of biological control of the invasive Phragmites australis in wetlands
The objective of this research was to explore the application of grazing by domestic livestock to control common reed, Phragmites australis, an invasive grass, in Maryland wetlands. The use of grazing as a management tool for promoting and maintaining plant biodiversity and rare species in wetlands has become widespread in Europe during recent decades. However, the primary means of control of Phragmites in the USA is herbicide, applied via helicopter or ground spraying, which are expensive and have negative environmental consequences including death of nontarget vegetation, toxicity to aquatic invertebrates and fish, and generation of greenhouse gases. Grazing by goats, sheep, and cattle has been used in the USA to successfully improve habitat for bog turtles, but this is the only example we have found in the scientific or gray literature of invasive plant control in US wetlands.
We set up experimental plots in a Phragmites-dominated wetland at the Beltsville Agricultural Research Center in Laurel, MD where goats were used to graze the Phragmites (paired with ungrazed plots). Preliminary results showed that grazing was highly effective in reducing Phragmites biomass (see photo below)with no observable impact on water or soil quality in the wetland. Animal health issues are a concern in this type of environment, and we -partnered with scientists from USDA’s Beltsville Agricultural Research Center to monitoring animal health and nutrition status. This research was supported by the Maryland Agricultural Experiment Station.
Plot of Phragmites australis grazed by goats (brown Drawing blood samples forplants in foreground) and another plot that was assessment of goat health. ungrazed (tall plants in background)
Dr. Baldwin has developed and taught courses on wetland ecology, wetland creation and restoration, water quality methods, ecological risk and impact assessment, and graduate seminars on wetland plant ecology. Several of his courses incorporate rigorous field and laboratory exercises, research projects, and data analysis, interpretation, and presentation. He has received several teaching awards, and led the development of the ENST undergraduate curriculum. In addition to teaching graduate and undergraduate courses, Dr. Baldwin has supervised the research of PhD and MS students and served on numerous graduate advisory committees.
Baldwin, A.H., K. Jensen, and M. Schönfeldt, 2014. Warming increases plant biomass and reduces diversity across continents, latitudes, and species migration scenarios in experimental wetland communities. Global Change Biology 20:835-850.
Baldwin, A.H., 2013. Nitrogen and phosphorus differentially affect annual and perennial plants in tidal freshwater and oligohaline wetlands. Estuaries and Coasts 36:547–558
Sharpe, P.J., and A.H. Baldwin, 2013. Wetland plant species richness across estuarine gradients: The role of environmental factors and the mid-domain effect. Aquatic Botany 107: 23–32.
Batzer, D.P., and A.H. Baldwin (eds.), 2012. Wetland Habitats of North America: Ecology and Conservation Concerns. University of California Press, Berkeley. 389 pp.
Baldwin, A.H., K.M. Kettenring, and D.F. Whigham, 2010. Seed banks of Phragmites australis-dominated brackish wetlands: Relationships to seed viability, inundation, and land cover. Aquatic Botany 93:163-169.
Neff, K.P., K. Rusello, and A.H. Baldwin, 2009. Rapid seed bank development in restored tidal freshwater wetlands. Restoration Ecology 17: 539-548.
Barendregt, A., D.F. Whigham, and A.H. Baldwin (eds.), 2009. Tidal Freshwater Wetlands. Backhuys Publishers, Leiden, The Netherlands. 320 pp.
Peterson, J.E., and A.H. Baldwin, 2004. Variations in seed and spore banks across a tidal freshwater landscape. American Journal of Botany 91: 1251-1259.
Baldwin, A.H., and I.A. Mendelssohn, 1998. Response of two oligohaline marsh communities to lethal and nonlethal disturbance. Oecologia 116: 543-555.
Baldwin, A.H., I.A. Mendelssohn, and K.L. McKee, 1996. The influence of vegetation, salinity, and inundation on seed banks of oligohaline coastal marshes. American Journal of Botany 83: 470 479.
Research ongoing in the Wetland Ecology and Engineering Laboratory focuses on the plant ecology of natural, restored, and treatment wetlands. Studies in the lab are generally framed in a community ecology approach involving the quantification of variables influencing vegetation structure and function such as hydroperiod, salinity regime, nutrient loading, sedimentation, disturbance processes, and soil characteristics.