PLANT COMMUNITY COMPOSITION, FLORISTIC QUALITY, AND ESTABLISHMENT OF ROADSIDE REVEGETATION IN NEBRASKA, USA.

Roadside revegetation poses a challenge and opportunity for biodiversity conservation, as the land area occupied by roadsides is not expected to decline in the future. In the context of roadside revegetation activities in rural regions dominated by agricultural land uses, revegetation efforts can establish plant communities that offer unique species that would otherwise be absent on the landscape. To determine the efficacy of roadside revegetation efforts in 1) providing plant communities of high biodiversity value and 2) meeting the expectations of roadside revegetation managers for establishment, we quantified botanical composition, floristic quality, and success in seeding efforts to meet manager expectations. We evaluate the outcome of roadside revegetation conducted by Nebraska Department of Transportation for five regions across Nebraska, USA: Loess hills and Glacial drift sites within the tallgrass prairie region, central Loess plains region, Sandhills region, and High Plains Panhandle region. Hereafter, we refer to these geographical areas as Northeast, Southeast, Central, Sandhills, and Panhandle regions, respectively. We found species richness and biodiversity of roadsides was greatest in the western regions of Nebraska. Biomass production on roadsides declined on an east to west gradient, but the component species responsible for this gradient were unique to each region. Manager expectations for established plant communities along roadsides were met at five of our 10 study sites, where significant correlations between managers’ expected communities and actual plant communities were observed. Our assessment occurred on average 13.2 years (range: 10-17) post-revegetation, thus, providing insight into what established roadside vegetation communities can be expected after a decade or more. Advisor: Walter H. Schach