The Impact of Fuel Load and Fire Season on the Control of Sericea Lespedeza

Abstract

Sericea lespedeza, Lespedeza cuneata, is an invasive species of legume introduced to North America in the 1800s. Since its introduction, it has become wide spread throughout the Midwest, having detrimental effects on tallgrass prairies by outcompeting native plant species and reducing forage production. Sericea lespedeza is also costly for range managers and landowners to control as current methods have had little success. I investigated a unique combination of control strategies at a plot size that replicates fire behavior seen in pasture-scale burns. These treatments included variations in fire season (spring or fall) coupled with treatments of herbicide, mowing, and fuel (litter) addition. I hypothesized that the subplots that received fuel load additions within the fall fire plots would have the greatest reduction on sericea lespedeza density, without affecting the productivity of native tallgrass prairie plant species compared to that of the herbicide, mowing, and spring burn treatments. In response to these treatment methods, I measured sericea lespedeza density and grassland system biomass to evaluate treatment effectiveness. This study was conducted at the Marais des Cygnes National Wildlife Refuge, Pleasanton, KS, a 25 year old tallgrass prairie restoration, operated by the U.S. Fish and Wildlife Service. Total standing biomass increased from 2014 to 2015, however, this is likely from the substantial increase in precipitation in 2015. Fall fire combined with mowing significantly decreases sericea lespedeza standing biomass.