Format: ORAL

Ana Novoa1, Mara L. Castillo1, Llewellyn C. Foxcroft2,3, Lus Gonzlez4, Desika Moodley1, Jan Cuda1, Martin Hejda1, Johannes J. Le Roux3,5, Khensani V. Nkuna2,3, Klara Pykov1,6,Petr Pyek1,6

1 Czech Academy of Sciences, Institute of Botany, Department of Invasion Ecology, Pruhonice, Czech Republic 2 Scientific Services, South African National Parks, Private Bag X402, Skukuza 1350, South Africa 3 Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa 4 Plant Ecophysiology Group: Invasive plants, Department of Plant Biology and Soil Sciences, Universidade de Vigo, 36310, Vigo, Spain 5 School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia 6 Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic

The number and magnitude of alien plant invasions in protected areas are increasing globally. In Kruger National Park (KNP), one of the worlds oldest and most widely known protected areas, 146 alien plant taxa have already become naturalized or invasive. Among these, three annual plants native to the Americas i.e., Xanthium strumarium L., Datura innoxia Mill., and Parthenium hysterophorus L. form extensive dominant stands along rivers. However, their environmental impacts in KNP has not yet been determined, specifically their effects on soil physicochemical attributes and microbial communities. To explore the potential impacts of these three species, we identified seven populations of each species throughout the park, and in each site, we selected a pair of invaded and uninvaded plots. Within each plot (14 plots per species, n = 42 plots), we collected five subsamples from the top 10 cm of soil and pooled them into a single replicate. Subsequently, we used these composite soil samples to analyze soil pH, humidity, nutrients (P, NO2-, NO3-, NH4+, and organic matter), enzymatic activities (glucosidase, urease, and phosphatase), and bacterial and fungal diversity. The findings of this research offer new insights into the impacts of annual alien plants on soil characteristics and bacterial and fungal communities in riparian habitats, thereby contributing to the strategic planning of invasive species management within an iconic protected area.