Fire Management in Fens and Wet 

Grasslands Grazed by Cattle

Open-File Report 2006-1268

U.S. Department of the Interior

U.S. Geological Survey
Fire Management in Fens and Wet Grasslands Grazed by 

Cattle 

By Beth A. Middleton 

Open-File Report 2006–1268 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey 

P. Patrick Leahy, Acting Director 

U.S. Geological Survey, Reston, Virginia 2006 

For product and ordering information: 

World Wide Web: http://www.usgs.gov/pubprod 

Telephone: 1-888-ASK-USGS 

For more information on the USGS—the Federal source for science about the Earth, 

its natural and living resources, natural hazards, and the environment: 

World Wide Web: http://www.usgs.gov 

Telephone: 1-888-ASK-USGS 

Suggested citation: 

Middleton, B.A., 2006, Fire management in fens and wet grasslands grazed by cattle: U.S. Geological Survey 

Open-File Report 2006-1268, 2 p. 

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government. 

 

ii
Fire Management in Fens and Wet Grasslands Grazed by 

Cattle 

By Beth A. Middleton 1

Managers grapple with the problem of shrub invasion in fens and wet grasslands, and the invasion of 

shrubs is a particular problem in newly acquired natural areas that were once grazed by cattle. Cattle 

grazing can cause shrub invasion by allowing the seedlings of shrubs, such as Redosier dogwood 

(Cornus sericea), an opportunity to invade after sedge (Carex stricta) tussocks are damaged by cattle 

and more light enters through the damaged canopy of the tussocks (fig. 1; Middleton, 2002a). In these 

wetlands, the biodiversity of forb species decreases as shrubs grow and increase the shade over the 

tussocks (Middleton, 2002a). Heavily grazed fens often have greatly reduced biodiversity (Middleton 

and others, in press), and such fens may need to be burned to reduce shrubs and then reseeded or planted 

with forbs as part of the restoration project. If such wetlands have been ditched or drained, burning may 

not be an option because the peat may catch on fire (Middleton and others, in press). Alternatively, 

drained fens can be mowed with a cutting machine or cut by hand. In Europe, handcutting of the 

vegetation of fens and wet grasslands is used to increase the biodiversity of forbs, and this practice is 

successful as long as previous cattle grazing has been relatively minor (Middleton and others, in press). 

Handcutting may be an option for the management of small wetlands, especially if volunteers are 

available. Also, it is important to remember that some amount of shrub cover is desirable in fens to 

create a mosaic of habitats. 

Figure 1. Redosier dogwood (Cornus sericea), a shrub that dominates fens after cattle grazing. 

Fires during very wet periods or during winter periods are not as effective in removing shrubs as 

are hot spring fires (Middleton, unpublished data). While fire increases forb flowering and density 

(Middleton, 2002b), the effects of fire only persist for 1 to 2 years (Kost and DeSteven, 2000). Ten 

years after a fire, the forb density begins to decrease again (Bowles and others, 1996). Therefore, from 

 

1

 U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Boulevard, Lafayette, LA 70506 

 

1
the perspective of the biodiversity conservation of fens and wet grasslands, it is important that these 

wetlands be mowed, cut by hand, or burned at least every few years (Middleton and others, in press). 

 The specific management for any particular fen or wet grassland depends greatly on its previous 

land-use history. Managers should have a clear understanding of the grazing and drainage history of 

newly acquired fens and wet grasslands so that well-informed management decisions can be made. 

References Cited 

Bowles, M., McBride, J., Stoynoff, N., and Johnson, K., 1996, Temporal changes in vegetation 

composition and structure in a fire-managed prairie fen: Natural Areas Journal, v. 16, p. 275-288. 

Kost, M.A., and DeSteven, D., 2000, Plant community responses to prescribed burning in Wisconsin 

sedge meadows: Natural Areas Journal, v. 20, p. 36-45. 

Middleton, B.A., 2002a, Nonequilibrium dynamics of sedge meadows grazed by cattle in southern 

Wisconsin: Plant Ecology, v. 161, p. 89-110. 

Middleton, B.A., 2002b, Winter burning and the reduction of Cornus sericea in sedge meadows in 

southern Wisconsin: Restoration Ecology, v. 10, p. 1-8. 

Middleton, B.A., Holsten, B., and van Diggelen, R., in press, Grazing of fens: a desirable management 

option?: Applied Vegetation Science. 

2