Invasive Plants. Restoration of Grasslands Invaded by Sericea Lespedeza

Master's Thesis from the year 2017 in the subject Biology - Botany, grade: 3.6, Southern Illinois University at Edwardsville (Graduate School), course: Environmental Science, language: English, abstract: Sericea lespedeza is an aggressive invasive plant which can suppress and displace native plant species in grasslands and prairies in the United States. The goal of the study is to determine how large the seed bank of lespedeza might be. Furthermore, the author tries to determine if a pre-emergent herbicide treatment could suppress Lespedeza germination and whether this provided benefits to a typical native species propagated into the site.

In the work, the author first characterized the soil seed bank at different invaded sites on SIUE campus using the seedling emergence method. In the second part, the author assessed the success of a pre-emergent herbicide in preventing the germination of lespedeza seed bank after lespedeza removal. The growth of a native grass (Sorghastrum nutans) as a replacement species has also been evaluated.

Currently Sericea lespedeza is rapidly spreading throughout the U.S and has been estimated to eventually invade about 61percent of the total land area. Lespedeza has become a successful colonizer because of its ability to tolerate and thrive under a wide range of environmental and soil conditions. Once established, lespedeza is very difficult to remove due to its persistent seed bank which can remain viable for years. To successfully control lespedeza, we must find effective ways to suppress or kill seeds in the soil, but this has received little research attention.