abundance, distribution and edge associations of six non-indigenous, harmful plants across North Carolina

Six species of non-indigenous, harmful plants were surveyed throughout North Carolina: Lonicera japonica, Rosa multiflora, Pueraria lobata, Ligustrum sinense, Ailanthus altissima, and Celastrus orbiculatus. On 417 randomly selected sites across the state, their occurrence was measured as linear presence along the edges of interstate highways, other federal highways, rivers, streams, and railroad and powerline rights-of-way. Their abundance was expressed as the percent of occurrence in the total length of measured transects. L. japonica occupied an average of 25.9% of all edge types, highest in the piedmont but fairly evenly distributed on edge types. L. sinense occupied an average of 7.5% of all edge types, highest along rivers and streams. R. multiflora occupied an average of 4.8% of all edges, highest along rivers and streams of the mountainous west. P. lobata occupied 2.4% of all edges, fairly evenly distributed on edge types. A. altissima occupied 1.7% of edges, especially high along railroad rights-of-way of the piedmont. C. orbiculatus occupied 0.6% of all edge types, highest along railroads of the mountains. Based on rates of accumulation of specimens in university herbaria, their rate of spread across the state was calculated and expressed as percent increase in counties reporting occurrences per year: R. multiflora = 8.63; P. lobata = 7.25; L. sinense = 5.38; A. altissima = 4.76; C. orbiculatus = 2.94. (Rate for Lonicera was probably highest but could not be calculated.)