Cutting, herbicide, and fire: a case study for managing woody plants in tallgrass prairies

Abstract Introduction The removal of clonal and resprouting woody plants expanding into mesic grasslands like tallgrass prairies can be expensive based on the types of treatments applied and subsequent retreatments. Objective We aimed to determine how combined herbicide application, mechanical treatments, and annual prescribed fire influenced grassland recovery from resprouting woody plants based on topographic locations (lowland, slope, upland) at the Konza Prairie Biological Station near Manhattan, Kansas, USA. Methods We assessed tree cover using the Rangeland Analysis Platform and monitored shrub stem densities and plant species composition across different topographic positions (lowland, slope, upland) for 4 years post‐woody plant removal. Specifically, we assessed which herbaceous species recolonized the treated woody plant areas or shrub islands and the stability of the recovering herbaceous community. Results Four years after herbicide, mechanical treatments and annual prescribed fire, tree cover remained low in the watershed. Shrub stem densities increased on the slopes and lowlands, but decreased in the uplands. In the lowlands, annual and perennial forb species rapidly colonized former shrub islands, while on the slopes and uplands shrub species maintained cover dominance even though upland stem densities were reduced. Conclusions This study shows that 4 years after herbicide and cutting/mowing treatments combined with annual fire, woody plants re‐established in the lowlands more readily than the other topographic positions, and the infilling of perennial grasses into former shrub island locations was not achieved to a desirable cover to be considered dominant. Tracking plant community trajectory could become an important monitoring strategy to verify if a management objective was met for restoring woody encroached grasslands.