Distribution, infestation, and habits of sericea lespedeza (Lespedeza cuneata) in Cowley County, Kansas

Sericea lespedeza [Lespedeza cuneata (Dumont) G. Don] is a non-native invasive plant that threatens the health of prairie and rangeland. A survey of rangeland in Cowley County, Kansas, was conducted to determine the spatial distribution, level of infestation, and estimated treatment cost. In addition, patterns of water distribution, soil type and forest cover were examined to determine if some areas were at a higher risk of invasion by sericea lespedeza. Sixty-six randomly determined quarter-sections were surveyed in the county by running two 800-meter transects at each location. Each transect was 2 m wide and consisted of 8 subsections. From these samples, it was determined that approximately 26,000 hectares (17%) of rangeland in the survey area contained sericea lespedeza. The levels of infestation ranged from sparse to severe. Sparse and scattered were the most frequent levels, and when combined, were found in 50% of the infested survey sites. The estimated cost for a one-year treatment is $186,486. Aerial photographs and Cowley County soil maps were used to identify the locations of bodies of water, forest cover, and soil type. Sericea lespedeza was found more often than expected at sites that contained ponds and streams, or which contained >1% forest cover. An association between the different soil types and sericea lespedeza was not found in this study. Based on these findings, sites where water is present or, which have forest cover are at a higher risk for infestation by sericea lespedeza.