Observations of extended lag phase of nonnative invasive Frangula alnus (Rhamnaceae) may be spatial-scale dependent1

摘要: Analysis of herbaria records allows for an examination patterns spatial spread nonnative plants in novel ranges, aiding understanding the processes that govern species invasions. I used to investigate rate and pattern establishment invasive plant Frangula alnus (Rhamnaceae) northeastern central North America. collected spanning a temporal range from ca. 1880 present covering entire invaded area northeast To address unequal sampling effort specimen collection, compared F. accessions with group ecologically similar native species. likely had multiple initial introductions into America were geographically separated, ranging southern Ontario coastal Mid-Atlantic region. Trends record collection time space show was initially slow, then increased rapidly during early 20th century, reached relatively constant later century. Examining this at continental scale, it appears have experienced extended lag phase its invasion history, but has steadily occupancy since 1920. This counters previous reports suggesting lasting 1970. These results raise question whether phases may be spatial-scale-specific pattern. The analytical methods presented here provide one way further.