A new publication in Scientific Reports highlights the alarming spread of two alien plant species in the San River basin: giant miscanthus (Miscanthus × giganteus) and Bisset's bamboo (Phyllostachys bissetii). The latter, in particular, is causing serious concern due to its high invasive potential. In a significant ecological development, Bisset's bamboo has already formed dense thickets along one of the rivers in the Subcarpathian region—marking the first documented wild population of this species in Europe.

Researchers from the University of Rzeszów, in collaboration with a representative from the Australian Invasive Species Council, issued an early warning in their study titled “Early warning of two emerging plant invaders in Europe” (Bylak A., Bobiec A., Bobiec M., Kukuła K., Low T. Sci Rep 15, 11666 (2025). https://doi.org/10.1038/s41598-025-95582-x).

The study draws attention to a critical ecological issue: both species belong to the group of tall grasses and have already begun colonizing natural habitats, primarily in riparian zones. According to the authors, the initial source of these plants may be domestic gardens. Discarded plant fragments deposited near watercourses have likely been transported downstream by water, leading to the establishment of independent populations.

In Krosno, Bisset's bamboo has formed a dense patch several meters tall along the Lubatówka River. The researchers warn that high water levels and strong winds may cause stalks to break or uproot, allowing them to re-root downstream—facilitating rapid expansion. Furthermore, the bamboo’s powerful underground rhizomes enable it to spread inland, making it a formidable invasive species. These dense bamboo thickets outcompete native vegetation and lead to a sharp decline in biodiversity along riverbanks.

Beyond local displacement of flora, the presence of bamboo could alter entire aquatic ecosystems. As the researchers note, the type and quantity of leaf litter entering rivers play a vital role in ecosystem function. Bamboo leaves, unlike those of willows or alders, may provide a poor food source for native aquatic invertebrates. This shift in organic input could disrupt the river’s food web, triggering broader ecological consequences.

The discovery of these two species in natural habitats underscores the risk posed by other ornamental plants—especially those from the genera Miscanthus and Phyllostachys. With their high invasive potential, the uncontrolled spread of such species could have serious and multifaceted impacts on local ecosystems.

The full article is available at: www.nature.com