The applications of herbicide use, native grass establishment, and invasive plant control to an integrated vegetation management research project in northwestern Indiana: Case study

Zachary Edward Lowe, Purdue University

Abstract

Herbicides are an important part of natural resource management. However, the environmental and social limitations of this tool in a land management setting are often not fully understood by either the general public or those responsible for the handling and safe use of herbicides. Educating both users and the general public is the responsibility of herbicide manufacturers, their distribution infrastructure, natural resources managers, and academic researchers. In 2003 Purdue University developed a research project in Tippecanoe County, Indiana that focused on the development and implementation of an integrated vegetation management process that would control invasive woody plants and establish prairie species. A significant portion of this research evolved from the requests of different natural resource managers. Their input and experiences were incorporated into treatments in an effort to enhance the integrated process, improve the applications of research, and educate as many managers as possible. To understand the limitations of prairie establishment, native warm-season grasses and forbs were planted in 2003-2005, paired with various imazapic herbicide treatments. The use of imazapic enhanced both the density and diversity of grasses established. Forb density and diversity was reduced with the use of imazapic, and forb diversity was generally low in all treatments. Simultaneous with the prairie establishment research, experiments were completed to determine appropriate control measures for woody invasive plants. Dormant season treatments on non-native species such as Amur honeysuckle (Lonicera maackii), autumn olive (Elaeagnus umbellata ), and multiflora rose (Rosa multiflora), and the invasive native species black cherry (Prunus serotina) resulted in 100% control of the stems treated. These results suggest that dormant season herbicide control methods are a useful tool for invasive plant control, specifically when used as part of an integrated plan. A final research trial was designed to test the integration of native plant establishment and invasive plant control techniques developed from the previous experiments. Previously tested methods were used as the first step in establishing a grassland savanna from a mid-successional brushland dominated by invasive woody plants (90.4% of the woody plants inventoried were invasive). My objectives for this study were to efficiently control the invasive woody plants, preserve the oak overstory, and establish native grasses within 2 growing seasons (18 months). These objectives were successfully met through the use of general-use forestry herbicides in an integrated vegetation management approach. The process included the use of a flail mower to reduce the biomass of the woody plants and a Truax Rough Rider Range Land Drill to plant the uneven terrain complexed by stumps, logs, and woody debris.

Degree

Ph.D.

Advisors

Weeks, Purdue University.

Subject Area

Forestry

COinS