Impact of Koenigia polystachya in its native range
Koenigia polystachya (Polygonaceae: EPPO Observation List) is native to the Himalayas (India and Pakistan) and is a non-native species with invasive behaviour in Canada, the EPPO region, North America and New Zealand. In the EPPO region, the species can form monocultures and often spreads along transportation routes (e.g. road and rail embankments). There are no known studies that have scientifically evaluated the impact of K. polystachya on native biodiversity and related ecosystem services in the EPPO region. Interestingly, however, several studies have been conducted in the plants’ native range, where the effect of the species’ expansion on native biodiversity has been assessed. The current study was conducted in the Valley of Flower National Park (VoFNP), Lata-Khark and Hemkund Sahib Trek in Nanda Devi Biosphere Reserve (NDBR) in the Indian western Himalayas. At each site, plots were established where K. polystachya was present and these were compared to plots where the species was absent. The expansion of K. polystachya was measured over four years (2015-2018) and the effect on plant species richness was studied. A total of 206 species of vascular plants were recorded during the study. In the invaded sites, species richness shows a gradual decrease over the years, while density and abundance of K. polystachya increased over the same period of time. Similar ecological studies could also be conducted in the invasive range which may help evaluate the risk the species has to biodiversity and associated ecosystem services.
Sources
* Negi VS, Maletha A, Pathak R, Maikhuri RK (2021) Expansion of a native species and its impact on alpine ecosystems, Indian Himalaya. Biologia 76, 889–899. https://doi.org/10.1007/s11756-021-00693-1