Irakli Mikeladze^1,2*, Davit Baratashvili², Lamzira Zoidze¹, Gia Bolkvadze¹, Marina Bakuridze²

¹Institute of Phytopathology and Biodiversity, Shota Rustaveli State University of Batumi (BSU), 6200 Kobuleti, Georgia

²Department of Biology, Shota Rustaveli State University of Batumi (BSU), 6010 Batumi, Georgia

 

*Corresponding author’s email: irakli.mikeladze@bsu.edu.ge

Received: 03 March 2026 / Revised: 22 June 2026 / Accepted: 01 July 2026 / Published Online: 07 September 2026

 

Abstract

 

Youngia japonica (L.) DC. is an East Asian alien plant species that has recently established populations in Western Georgia, particularly within the Colchis lowland. This study examines its biomorphological traits, phenological rhythm, and ecological adaptability in newly colonized habitats. Field investigations conducted between 2016 and 2025 revealed that Y. japonica completes its full life cycle in Western Georgia (Colchis lowland), with germination typically beginning in late summer, flowering occurring in spring, and the vegetation phase concluding by mid-summer. Despite a shorter flowering and fruiting period compared to its native range, the species produces viable seeds and demonstrates strong ecological plasticity. It thrives in diverse habitats, including agroecosystems, ruderal areas, and disturbed urban substrates, and regenerates effectively after mechanical disturbance. A comparative analysis with other regions confirms its high invasive potential and adaptability. The study underscores the importance of phenological monitoring and early detection for managing the species’ spread in Georgia (Colchis lowland).

 

Keywords: Alien species, Colchis lowland, Ecological plasticity, Invasive plants, Phenology, Seasonal development, Youngia japonica

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