Beth Middleton is a Research Ecologist at the USGS Wetland and Aquatic Research Center.
Wetland function may be altered in the future because of dynamic shifts in droughts, water extraction, water fluctuation, salinity intrusion, CO2 levels, and storm intensity. Populations of species can be extirpated especially by drought, and tree mortality is especially common at the edges of species diestribution ranges during drought. Beth Middleton examines patterns of ecosystem function along latitudinal gradients in baldcypress swamps, monsoonal wetlands, mangrove swamps, northern peatleands, prairie fens, and floodplain wetlands. She has organized symposia, written three books, and edited three special journal volumes, which support multidisciplinary comparisons and research analysis of wetland function. Other research topics include the effects of hurricanes on coastal wetlands, flood pulsing in restoration, and biodiversity loss in fens of Europe, Asia and North America. Middleton maintains a research network of baldcypress swamps (North American Baldcypress Swamp Network) and invites other researchers to work in these study sites dedicated to the study of long term function of swamps in the southeastern US.
Education and Certifications
Ph.D., Botany, Iowa State University, 1989
Advisors: van der Valk/DavisM.S., University of Minnesota Duluth, 1983
B.S., University of Wisconsin Madison, 1978
Science and Products
Zapata Bladderpod and Prostrate Milkweed Landscape Ecology, Seed Dispersal, Pollinators, and Border Fence Mitigation
Purple Loosestrife in Louisiana: A Call for Citizen Scientists
Integrating Science and Management for Optimal Prevention and Control of Invasive Nymphoides in Florida
Wetland Forest Regeneration Dynamics and Productivity in Southeastern Cypress Swamp Ecosystems
Joint Research on Water and Sedimentation Changes and Potential Impacts on Biodiversity along the Porsuk River, Turkey
Long-term Trends in Swamp Tree Growth across Drought and Salinity Gradients along the Northern Gulf Coast
Geographical Trends in Ecosystem Function and Biodiversity of Wetlands as a Surrogate for Climate Change
Salinity Intrusion Impacts from Hurricane Sandy in Tidal Freshwater Swamps, Delmarva Peninsula, Mid-Atlantic Coast, USA
Potential Impact of Hydrology and Sedimentation Changes to Biodiversity, Dongting Lake, China
Data Release: Buttonland Swamp, seed data
Data Release: Buttonland Swamp, population projection
Data Release: Buttonland Swamp, health survey, 2022
Data Release: Buttonland Swamp, reproduction, 2006 to 2021
Data Release: Germination and growth of Montezuma cypress (Taxodium mucronatum) from the Nazas River to experimental salinity treatments
Data Release: Buttonland Swamp, SET data
Data Release: Buttonland Swamp, water data, 2021
Data Release: Seed banks of rare Physostegia correllii in Lady Bird Johnson Lake, Austin, Texas
Data Release: Mercury accumulation potential of aquatic plant species in West Dongting Lake, China
Effects of shading on the rare plant species, Trillium texanum (Melanthiaceae)
Effects of shading on the rare plant species, Physostegia correllii (Lamiaceae)
Data Release: Peat collapse and vegetation shift after storm-driven saltwater surge in a tidal freshwater swamp, Taxodium distichum growth
Decadal shifts in the population growth, regeneration, and health of Taxodium distichum in swamps of the Cache River Watershed, Illinois
An inconvenient trend: Decadal decline in ground height of swamps in Southern Illinois
Seed banks of rare Physostegia correllii (Lamiaceae) in Lady Bird Lake, Austin, Texas, U.S.A.
Mercury accumulation potential of aquatic plant species in West Dongting Lake, China
Effects of shading on the rare plant species, Physostegia correllii (Lamiaceae) and Trillium texanum (Melanthiaceae)
Trends in vegetation and height of the topographic surface in a tidal freshwater swamp experiencing rooting zone saltwater intrusion
The vegetation dynamics of the monsoonal wetland of the Keoladeo National Park, India: A reassessment
Ventilation systems in wetland plant species
Worldwide wetland loss and conservation of biodiversity and ecosystem services
Salinification of coastal wetlands and freshwater management to support resilience
Regeneration trends along climate gradients in Taxodium distichum forests of the southeastern United States
Restoration of organic coastal and inland freshwater forests
Non-USGS Publications**
http://onlinelibrary.wiley.com/doi/10.1111/j.1526-100X.1995.tb00099.x/abstract
www.jstor.org/stable/pdfplus/2559700.pdf OR www.journals.cambridge.org/action/displayAbstract?fromPage=online&aid=5248088
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Zapata Bladderpod and Prostrate Milkweed Landscape Ecology, Seed Dispersal, Pollinators, and Border Fence Mitigation
USGS is studying how the current border fence designs or positions in the Lower Rio Grande Valley, Texas, impact seed dispersal and pollinator movement across the border.Purple Loosestrife in Louisiana: A Call for Citizen Scientists
Join USGS in helping to prevent the spread of the invasive purple loosestrife in Louisiana.Integrating Science and Management for Optimal Prevention and Control of Invasive Nymphoides in Florida
Two invasive species of floating hearts, Nymphoides cristata and N. indica, are actively managed in Florida. A rare native species, N. humboldtiana, has been found in Florida and verified by molecular methods; this species is nearly indistinguishable from N. indica.Wetland Forest Regeneration Dynamics and Productivity in Southeastern Cypress Swamp Ecosystems
Relict forests (i.e., forests unable to reestablish after disturbance) may develop in the southeastern U.S. in future predicted extreme climates of temperature, flooding, and drought, according to the International Panel on Climate Change.Joint Research on Water and Sedimentation Changes and Potential Impacts on Biodiversity along the Porsuk River, Turkey
The Porsuk River floodplain near Eskisehir, Turkey contains a large number of wetlands, which have been managed by humans for millennia.Long-term Trends in Swamp Tree Growth across Drought and Salinity Gradients along the Northern Gulf Coast
This study will examine the potential effects of climate-change-induced sea level rise, drought and water extraction by examining tree growth patterns across the Gulf Coast, specifically targeting long-term research plots available in the North American Baldcypress Swamp Network (NABCSN) and the Suwannee River.Geographical Trends in Ecosystem Function and Biodiversity of Wetlands as a Surrogate for Climate Change
Extreme drought and temperature in the southeastern United States may become more frequent in the future, and any extreme shifts in climate condition are likely to have effects on wetland ecosystem function. USGS research predicts the effects of climate change by shifts in function and biodiversity across existing climate gradients in baldcypress swamps.Salinity Intrusion Impacts from Hurricane Sandy in Tidal Freshwater Swamps, Delmarva Peninsula, Mid-Atlantic Coast, USA
When it comes to hurricanes, wind and storm surge effect vegetation differently. USGS anlyzes these differences following Hurricane Sandy to help inform management on storm mitigation and long-term planning.Potential Impact of Hydrology and Sedimentation Changes to Biodiversity, Dongting Lake, China
Dongting Lake, one of the wetlands that make up the floodplains of China's Yangtze River, is important habitat for migratory waterfowl and other wildlife. However, the re-engineering of the water way and the intensification of agricultural practices has contributed to changes in hydrology and sedimentation. USGS and partners from China are assessing the potential impact of these changes to the... - Data
Filter Total Items: 23
Data Release: Buttonland Swamp, seed data
This dataset contains canopy measurements of Taxodium distichum taken outside of the Wetland and Aquatic Research Center in Lafayette, Louisiana. The measurements were used to produce data on tree canopy area and seeds produced per Taxodium distichum tree.Data Release: Buttonland Swamp, population projection
This dataset is part of a population model of Buttonland Swamp in the Cache River Watershed of Illinois. The modeling spans three decades of data from 1990 to 2021. This dataset is used to compare regeneration of Taxodium distichum along a moisture gradient of drier to wetter: Section 8 Woods (2006-2011), Crawford Tract mid-elevation, Eagle Pond, Deer Pond, Wildcat Bluff, Snake Hole, Crawford TracData Release: Buttonland Swamp, health survey, 2022
This dataset contains tree health information in 2022 for ten trees in Buttonland Swamp, part of the Cache River Watershed in Illinois. The data includes the height of the trees along with their crown ratio. This allows an understanding of the size and canopy health of Buttonland Swamp cypress trees. A Munsell color chart was utilized in determining leaf color. Leaf color tells whether the trees aData Release: Buttonland Swamp, reproduction, 2006 to 2021
This dataset represents annual reproductive litterfall collections and seedling data from Crawford Tract, Eagle Pond, Section 8 Woods, Deer Pond, Wildcat Bluff, Snake Hole, and Heron Pond from 2006 to 2021. These sites are part of the study location, Buttonland Swamp, within the Cache River Watershed, Illinois. Summer and winter water depths were also included in the dataset.Data Release: Germination and growth of Montezuma cypress (Taxodium mucronatum) from the Nazas River to experimental salinity treatments
During March and April of 2018, viable seeds were collected from Cañón de Fernández State Park in Lerdo, Durango and sent to Lafayette, LA for germination. This study tested the seedling growth and germination of Taxodium mucronatum from the Nazas River watershed at different salinity concentrations representing freshwater, moderate salinity, and high salinity.Data Release: Buttonland Swamp, SET data
This study examined long-term changes in ground height using Surface Elevation Tables (SETs). Measurements were taken in the floodplains of the Cache River at Buttonland Swamp in southern Illinois. The sites where data was collected included Crawford Tract and Eagle Pond from 2020-2022 and Deer Pond and Snake Hole from 2005-2022.Data Release: Buttonland Swamp, water data, 2021
A Solinist water logger was used to collect water data at the Crawford Tract section of the Cache River Watershed in Illinois from June 22nd to November 29th of 2021. This data included temperature, pressure, and depth.Data Release: Seed banks of rare Physostegia correllii in Lady Bird Johnson Lake, Austin, Texas
Soil samples were collected from Lady Bird Johnson Lake, Austin, Texas in 2019 to generate seed bank data for the rare plant Physostegia correllii. Seed germination data was produced from the soil samples kept in a greenhouse at the Wetland and Aquatic Research Center in Lafayette, LA.Data Release: Mercury accumulation potential of aquatic plant species in West Dongting Lake, China
An ecological study on mercury contamination in the wetland of West Dongting Lake in China. This study measured the total mercury concentration in the soil and compared it to the measured total concentration of mercury in the above and below ground tissue of different plant species on the floodplain of West Dongting Lake. Bioconcentration, bioaccumulation, and translocation factors were determinedEffects of shading on the rare plant species, Trillium texanum (Melanthiaceae)
The original distribution of the study species Trillium texanum is seep spring baygalls in east-central Texas and extreme northwestern Louisiana. Experiments to determine the effects of shading on T. texanum were conducted using short-term shade cloth treatments (full sunlight vs. 30% shading for 2-3 weeks), and a dryness treatment (moist vs. less moist). Mean height and cover responses of individEffects of shading on the rare plant species, Physostegia correllii (Lamiaceae)
The original distribution of the study species Physostegia correllii included freshwater floodplains of large rivers in the southcentral U.S. (Colorado, Rio Grande, Mississippi). Experiments to determine the effects of shading on P. correllii were conducted using short-term shade cloth treatments (full sunlight vs. 30% shading for 2-3 weeks). Mean height and cover responses of individuals were detData Release: Peat collapse and vegetation shift after storm-driven saltwater surge in a tidal freshwater swamp, Taxodium distichum growth
In 2013 five Taxodium distichum trees along a 125 m long transect of Hickory Point State Forest outside Pocomoke City, Maryland were outfitted with dendrobands. Each year the growth of the T. distichum trees was measured in terms of the ratio of that year's circumference to the previous year's circumference. Tree growth was measured until the year the tree died or the conclusion of the study in 20 - Publications
Filter Total Items: 114
Decadal shifts in the population growth, regeneration, and health of Taxodium distichum in swamps of the Cache River Watershed, Illinois
Population projection models based on long-term trends in regeneration and tree survival can be used to predict the future stability of swamp forest species using water management. Population growth and regeneration of a foundational tree species in North American cypress swamps (Taxodium distichum) were compared in the Cache River watershed of southern Illinois USA over several decades. This studAuthorsBeth Middleton, Darren JohnsonAn inconvenient trend: Decadal decline in ground height of swamps in Southern Illinois
An understanding of the long-term trends of ground height and sedimentation in a landscape context can provide a framework to better understand the impacts of agricultural development on floodplain processes. This study examined long-term changes in ground height using surface elevation tables (SETs) and sediment deposition measurements in the Cache River floodplains of Southern Illinois includingAuthorsBeth MiddletonSeed banks of rare Physostegia correllii (Lamiaceae) in Lady Bird Lake, Austin, Texas, U.S.A.
Rare species threatened by climate and land-use change may harbor seeds in soil seed banks for periods of time even if adults have disappeared from the site. Soil samples were collected from sites with current Phyostegia correllii populations and from sites with former populations in Lady Bird Lake (a reservoir of the Colorado River, Austin, Texas. A seedling emergence study was conducted under grAuthorsBeth Middleton, Casey R. WilliamsMercury accumulation potential of aquatic plant species in West Dongting Lake, China
West Dongting Lake is a protected wetland with the potential for high levels of mercury release via wastewater and deposition from industry and agriculture during the last decade. To find out the ability of various plant species to accumulate mercury pollutants from soil and water, nine sites were studied in the downstream direction of the flow of the Yuan and Li Rivers, which are tributaries of tAuthorsDong Peng, Mingzhu Chen, Xinyue Su, Chenchen Liu, Zhehao Zhang, Beth Middleton, Ting LeiEffects of shading on the rare plant species, Physostegia correllii (Lamiaceae) and Trillium texanum (Melanthiaceae)
Rare plant species that are constrained by shading may be threatened by a lack of natural disturbance that removes overhanging vegetation. The original distribution of the study species Physostegia correllii (Lundell) Shinners included freshwater floodplains of large rivers in the southcentral U.S. (Colorado, Rio Grande, and Mississippi rivers). A second species, Trillium texanum Buckley was foundAuthorsBeth Middleton, Casey R. Williams, Chris Doffitt, Darren JohnsonTrends in vegetation and height of the topographic surface in a tidal freshwater swamp experiencing rooting zone saltwater intrusion
A decrease in the ground surface height of coastal wetlands is of worldwide concern because of its relationship to peat loss, coastal carbon, and biodiversity in freshwater wetlands. We asked if it is possible to determine indicators of impending transitions of freshwater swamps to other coastal types by examining long-term changes in the environment and vegetation. In a tidal Taxodium distichum sAuthorsBeth Middleton, John L. DavidThe vegetation dynamics of the monsoonal wetland of the Keoladeo National Park, India: A reassessment
As a result of a field trip in 1980 to the monsoonal wetland of the Keoladeo National Park, India, which was organized by Dr. Brij Gopal, a study of the vegetation dynamics of this wetland was initiated. The original hypothesis for this study was that the seasonal vegetation changes caused by the annual summer monsoon was a compressed habitat cycle. Habitat cycles are a characteristic of prairie pAuthorsArnold G. van der Valk, Beth MiddletonVentilation systems in wetland plant species
Molecular oxygen and carbon dioxide may be limited for aquatic plants, but they have various mechanisms for acquiring these gases from the atmosphere, soil, or metabolic processes. The most common adaptations of aquatic plants involve various aerenchymatic structures, which occur in various organs, and enable the throughflow of gases. These gases can be transferred in emergent plants by molecularAuthorsLars O. Björn, Beth Middleton, Mateja Germ, Alenka GaberščikWorldwide wetland loss and conservation of biodiversity and ecosystem services
Aim: Best strategies for future conservation and management to address global and regional trends in wetland loss and degradation are assessed in this article.Main concepts covered: Direct drivers of wetland loss and change include land drainage and filling, hydrologic alteration, degradation from pollutants and sediments, and conversion to agriculture, urban and industrial usage. Estimates of gloAuthorsBeth MiddletonSalinification of coastal wetlands and freshwater management to support resilience
Climates are rapidly changing in wetland ecosystems around the world and historical land-use change is not always given enough consideration in climate adaptation discussions. Historical changes to hydrology and other key environments can exacerbate vegetation stress; e.g., recent drought and flood episodes are likely more extreme because of climate change. The contributions of global and regionalAuthorsBeth Middleton, Jere BoudellRegeneration trends along climate gradients in Taxodium distichum forests of the southeastern United States
The development of relict vegetation at the edges of some ecosystems has taken place particularly in environments where the regeneration of foundational species is declining. As an important stage of regeneration in the Taxodium distichum, this study explored the relationship of cone volume and seed number across environmental gradients in the Mississippi River Alluvial Valley (MRAV) and northernAuthorsBeth Middleton, Ting Lei, Omag Villegas, Xiaohui LiuRestoration of organic coastal and inland freshwater forests
Peatland forests occur worldwide in inundated soils where primary production and anaerobic conditions contribute to the building of soil organic matter (Günther et al., 2020). Greenhouse gas emissions (GHG) can be substantial from drained freshwater forests with organic soils. Therefore, rewetting peat via hydrologic restoration (see factsheet n°12 on Peatland restoration, this volume) can restoreAuthorsBeth Middleton, Eric Ward, Lorenzo MenichettiNon-USGS Publications**
Middleton, B.A. 2002. Nonequilibrium dynamics of sedge meadows grazed by cattle in southern Wisconsin. Plant Ecology 161:89-110. www.springerlink.com/content/v0l42625k0g21141/Xiao, N., D.A. Bennett, B. Middleton, and K. Fessel. 2002. SISM: a multiscale model cypress swamp regeneration. Geographical & Environmental Modelling 6:99-116. www.tandfonline.com/doi/abs/10.1080/13615930220127314Middleton, B.A. 2002. Winter burning and the reduction of Cornus sericea in sedge meadows in southern Wisconsin. Restoration Ecology 10:1-8. https://doi.org/10.1046/j.1526-100X.2002.01053.xMiddleton, B.A. 2001. A case for wetland restoration. Book review. Restoration Ecology 9:247-248. www3.interscience.wiley.com/cgi-bin/fulltext/118995575/PDFSTARTSpyreas, G., D.J. Gibson, and B.A. Middleton. 2001. Effects of endophyte infection in tall fescue (Festuca arundinacea: Poaceae) on community diversity. International Journal of Plant Science 162:1237-1245. www.plantbiology.siu.edu/faculty/Gibson/IJPS2001.pdfMiddleton, B.A. 2000. Hydrochory, seed banks, and regeneration dynamics across landscape boundaries in a forested wetland. Plant Ecology 146:169-184. www.springerlink.com/content/w28pp67819819074/Gibson, D. J., B.A. Middleton, G.W. Saunders, M. Mathis. W.T Weaver, J. Neely, J. Rivera and M. Oyler. 1999. Learning by doing ecology: long term field experiments in ecology. IF0.3/C12 American Biology Teacher 61:217-222. www.jstor.org/discover/10.2307/4450654?uid=3739688&uid=2129&uid=2&uid=70&uid=4&uid=3739256&sid=55902219473Rice, M., B.A. Middleton and D. Gibson. 1999. Fractal analysis of movement pathways in vegetated and unvegetated microlandscapes. Bios 1:176-184. _/C2. www.jstor.org/discover/10.2307/4608479?uid=3739688&uid=2&uid=4&uid=3739256&sid=55902222123Oyler, M., J. Rivera, M. Roffel, D. J. Gibson, B.A. Middleton and M. Mathis. 1999. The macaroni lab: a directed inquiry project on predator-prey relationships. American Biology Teacher 40:39-41. IF0.3/C1 www.plantbiology.siu.edu/faculty/gibson/macaron.pdfMiddleton, B.A. 1999. Flood pulsing in restoration: a feasible alternative for India? Journal of the Ecological Society 12:10-14.Mathis, M. and B.A. Middleton. 1999. Simulated herbivory and vegetation dynamics in coal slurry ponds reclaimed as wetlands. Restoration Ecology 7:392-398. IF2.2/C10 http://onlinelibrary.wiley.com/doi/10.1046/j.1526-100X.1999.72034.x/abstractMiddleton, B.A. 1998. Succession and herbivory in monsoonal wetlands. Wetland Ecology and Management 6:189-202. IF0.3/C32 www.springerlink.com/content/r30811h62j6741u5/Middleton, B.A. 1998. The water buffalo controversy in the Keoladeo National Park, India. Ecological Modelling 106:93-95. IF2.7/C9 http://cat.inist.fr/?aModele=afficheN&cpsidt=2218674Middleton, B.A. 1998. Reply to: The water buffalo controversy in the Keoladeo National Park, India. Ecological Modelling 106:95-98. IF2.7/C9 http://cat.inist.fr/?aModele=afficheN&cpsidt=2218674Middleton, B.A., E. Sanchez-Rojas, B. Suedmeyer and A. Michels. 1997. Fire in a tropical dry forest of Central America: A natural part of the disturbance regime? Biotropica 29:515-517. IF2.6/C47 www.jstor.org/discover/10.2307/2388944?uid=3739688&uid=2129&uid=2&uid=70&uid=4&uid=3739256&sid=55901Akanil, N. and B.A. Middleton. 1997. Leaf litter decomposition along the Porsuk River, Eskisehir, Turkey. Canadian Journal of Botany 75:1394-1397. www.nrcresearchpress.com/doi/abs/10.1139/b97-853 OR www.nrcresearchpress.com/doi/abs/10.1139/b97-853Middleton, B.A. 1995. Ecology of greenways. Book review. Restoration Ecology 3: 319-322.Middleton, B.A. 1995. Seed banks and species richness potential of coal slurry ponds reclaimed as wetlands. Restoration Ecology 3:311-318.
http://onlinelibrary.wiley.com/doi/10.1111/j.1526-100X.1995.tb00099.x/abstract
Middleton, B.A. and U. Melkania. 1995. Decomposition of wet grassland species in a stream of the Himalayan terai, Pantnagar, Uttar Pradesh, India. International Journal of Ecology and Environmental Sciences 21:163-168. www.nieindia.org/ijees/abstracts/v21/abstrv21_163.aspMiddleton, B.A. 1995. Sampling devices for the measurement of seed rain and hydrochory in rivers. Journal of the Torrey Botanical Club 122:152-155. www.jstor.org/discover/10.2307/2996454?uid=3739688&uid=2&uid=4&uid=3739256&sid=55901569553Middleton, B.A. 1994. Decomposition and litter production in a northern bald cypress swamp. Journal of Vegetation Science 5:271-274. www.jstor.org/stable/pdfplus/3236160.pdfMiddleton, B.A. and E. Sanchez. 1994. Microhistological analysis of food habits in the tropics. Vida Silvestre 3:41-47.Middleton, B.A. 1994. Management of monsoonal wetlands for Greylag and Barheaded Geese in the Keoladeo National Park, India. International Journal of Ecology and Environmental Sciences 20:1263-171. www.nieindia.org/ijees/abstracts/v20/abstrv20_163.aspvan der Valk, A. G., B.A. Middleton, R. L. Williams, D. H. Mason and C. Davis. 1993. The biomass of an Indian monsoonal wetland before and after being overgrown with Paspalum distichum. Vegetatio 109:81-90. www.springerlink.com/content/w3866315p4450555/fulltext.pdfMiddleton, B. A. 1992. Habitat and food preferences of geese overwintering in the Keoladeo National Park, Bharatpur, India. Journal of Tropical Ecology 8:181-193.
www.jstor.org/stable/pdfplus/2559700.pdf OR www.journals.cambridge.org/action/displayAbstract?fromPage=online&aid=5248088
Middleton, B.A., A.G. van der Valk, C.B. Davis, D.H. Mason, and R.L. Williams. 1992. Litter decomposition in an Indian monsoonal wetland overgrown with Paspalum distichum. Wetlands 12:37-44. www.springerlink.com/content/w3866315p4450555/Middleton, B.A. and D.H. Mason. 1992. Seed herbivory by nilgai, feral cattle, and wild boar in the Keoladeo National Park, Bharatpur, India. Biotropica 24:538-543. www.jstor.org/stable/pdfplus/2389017.pdfMiddleton, B.A., A.G. van der Valk, R.L. Williams, D.J. Mason, and C.B. Davis. 1991. Vegetation dynamics and seed banks of a monsoonal wetland overgrown with Paspalum distichum in northern India. Aquatic Botany 40:239-259. www.sciencedirect.com/science/article/pii/0304377091900619Middleton, B.A. 1990. Effect of water depth and clipping frequency on the growth and survival of four wetland plant species. Aquatic Botany 37:189-196. www.sciencedirect.com/science/article/pii/030437709090091XMiddleton, B.A.1988. Food habits of geese in northern India. Journal of the Ecological Society (India) 1:37-45.Middleton, B.A. and A.G. van der Valk. 1987. The food habits of Greylag and Barheaded Geese in the Keoladeo National Park, India. Wildfowl 38:94-102. /C122 http://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/774/774Middleton, B.A. and D.J. Schimpf. 1986. Sand movement and vegetation in the Apostle Islands, Lake Superior. Canadian Journal of Botany 64:1671-1674. www.nrcresearchpress.com/doi/abs/10.1139/b86-223**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.