Why Historical Processes Matter: Differential Effects of Hay-Mowing and Fire on a Tallgrass Prairie

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Historically, human-ignited fires were responsible for the extensive tallgrass ecosystems found east of the Mississippi Rive. More recently, fire was been the single best tool for restoring and conserving tallgrass prairie communities. Mowing is an often recommended substitute for fire, although there has been little evaluation of how well mowing mimics fire. In 2005 we resampled a tallgrass prairie remnant that had been originally sampled in 1948 and had been resampled in 1977, using 114 2 m x 2 m permanently located plots. We were initially surprised when the data revealed a substantial change between 1948 and 1977 and little change between 1977 and 2005. The early changes included a doubling of mean number of species per plot (12.3 in 1948, 25.1 in 1977, 25.5 in 2005) and increased frequencies of shrubs, aspen, C4 grasses (especially Sporobolus heterolepis), and some forbs, including rare species. However the periods of change and stability made sense in light of changes in management practices. The site had been harvested for hay prior to 1948 and had been frequently burned since the early 1950s. This study indicates the differential effects of fire versus hay-mowing that must be considered in conserving tallgrass prairie.


Presented at the Plant Biology & Botany 2007 Joint Congress, Chicago, IL.

Abstract ID 2223.