Restoring the Prairies of Wilson's Creek National Battlefield

Restored tallgrass prairie at Wilson's Creek National Battlefield, 2020. NPS.

Why a battlefield restores prairie

Wilson's Creek National Battlefield in Missouri commemorates the 1861 Civil War battle for control of the state. The landscape shaped the battle's strategy and outcome, so restoring what the ground looked like then has been a priority since the park was founded.

• The park lies where the Osage Plains meet the Ozark woodlands, so it holds woodlands, prairies and glades.
• At the time of the battle the area was mostly savanna and grassland, with some open woodland and farms with crops and pasture.
• Fire kept the prairies open. Long-term fire suppression let the landscape change.

Restoration

• Late 1970s to 1993: the park replanted its prairies.
• 1988: prescribed fire was introduced.
• Today the park uses fire, cutting and mowing to keep woodlands open, remove invasive plants and support healthy, diverse native prairie.

What is monitored

The Heartland Inventory and Monitoring Network has monitored the park's prairie plants since 1988. Six permanent plots set up in 2008 (sites 14 through 19) were surveyed in 2008, 2012, 2016 and 2020. The crews record:

• climate and fire history
• how many plant species grow there
• plant cover — how much ground each species covers, a measure of abundance
• how much ground is covered by plant litter or rock
• how many trees, seedlings and saplings are growing in the prairie

Together these show the prairie's condition over time, and whether management is keeping it open and diverse.

Wildflowers at Wilson's Creek National Battlefield. NPS.

Findings, 2008–2020

• Weather: rainfall was mostly normal to above normal, with drought in 2012 and dry spells in 2016. Prairies are adapted to drought, but fewer species appeared in dry years.
• Diversity: the plant community remains moderately diverse.
• Nonnative plants: nonnative forbs have declined; nonnative grasses have increased.
• Woody plants: tree seedlings and saplings have increased. Four of the six sites now resemble shrubland more than tallgrass prairie, and a fifth is shrubland-savanna.
• Fire: prescribed burns have become less frequent; the prairies are now kept mostly by mowing and herbicide.

What would help: more frequent fire, continued treatment of nonnative plants, and fewer woody plants — to stop the prairie turning into savanna and woodland.

A monarch caterpillar on milkweed. Monarchs depend on milkweeds at every stage of life. NPS.

Milkweeds and monarchs

Milkweeds are critical for pollinators, especially the monarch butterfly, a candidate for listing under the Endangered Species Act. Prairies give milkweeds the conditions they need.

• Five milkweed species have been found on the monitoring sites since 2008.
• They are not abundant, but grew on all six sites in wet years and on two or three in dry years.
• Burning, mowing and herbicide work timed outside pollinator breeding and blooming seasons will help keep habitat for monarchs and other imperiled pollinators.

Managing the prairie for pollinators is ecologically important — and it also helps keep the scene as it was at the time of the battle.

Sources

Based on "Prairie Plant Community Monitoring at Wilson's Creek National Battlefield," Heartland Inventory and Monitoring Network, National Park Service; a work of the United States government in the public domain. The full report is in the NPS DataStore. The article's map of monitoring sites, drawn on aerial imagery, is not reproduced.