The alien invasive yellow flag (Iris pseudacorus L.) in Argentinian wetlands: assessing geographical distribution through different data sources

Abstract

The yellow flag, Iris pseudacorus L. (Iridaceae) is an emergent perennial wetland plant native to the Palearctic region and has been dispersed worldwide as an ornamental plant. In the introduced range, it is highly invasive in natural and artificial waterbodies. Currently, this species is difficult to manage and continues to spread, causing significant environmental impacts. The aims of this study were to assess the geographical range of I. pseudacorus in Argentina by compiling data from literature, collections, citizen science and field surveys. An exhaustive review of herbarium collections and literature was conducted and a database with reports obtained through citizen science was obtained and used to design routes for field surveys. 114 records of I. pseudacorus were obtained, mainly in humid and disturbed areas. The oldest records date from 1931 and 1933, and the number of reported localities showed a gradual increase with time. Fifteen records of the weed were from protected areas, four of which have international conservation status. This study shows that I. pseudacorus is increasing in distribution in Argentina and that citizen science can be used to document the distribution of invasive alien plant species. Taking into account that the number of records obtained from herbarium collections was greater than the number of records from literature, this study shows the value of these as database that allows historical reconstructions. This study is part of a collaborative “Global South” alliance between Argentina, South Africa and New Zealand, determining the extent of I. pseudacorus invasion in the southern hemisphere and generating management strategies for its control.