To Establish a Healthy Forest: Restoration of the Forest Herb Layer on a Reclaimed Mine Site

Abstract

Restoration efforts, such as invasive species removal and establishment of native flora, can be resource intensive. Therefore, understanding the effectiveness of restoration efforts can provide land managers with the confidence to pursue restoration. This study evaluated the effects of invasive species removal and compared active revegetation to passive revegetation in enhancing forest integrity on reclaimed surface coal mine land in southeastern Ohio. Surface coal mining occurred in the area from the 1940s to the 1980s, leaving a near continuous disturbance footprint of 3704.5 ha. This study occurred within 3.6 ha of the larger disturbance footprint where mining activity ceased and reclamation with tree planting occurred in the 1960s. Due to the disturbance, the site was prone to invasive species until their removal began in 2017. In spring 2019, 2 y following invasive species removal and 1 y following seeding and planting, we completed vegetation and bloom surveys across three treatments: managed forest with invasive species removed and subsequent native plantings (planted), managed forest with invasive species removed only (unplanted), and unmanaged forest (control). Our study found vegetative species diversity, vegetative species richness, and floral species richness and bloom time were enhanced for treatments in which invasive species were removed. The planted and unplanted treatments also supported understories comprising a different community composition when compared to control plots. However, no difference was found in community composition between planted and unplanted treatments despite application of active revegetation to support understory regeneration. Overall, results after 2 y support invasive species removal to improve the herbaceous layer of an understory, with more time likely needed for planted material to establish in order to distinguish between revegetation methods.