Does clonal growth rate vary during old-field succession? A field study of the perennial grassland forb Fragaria viridis Weston

Clonal plants shape community assembly after disturbance through spatial patch formation and species coexistence. Successional processes may also affect clonal growth dynamics and establishment success of individual species, yet genet-level information across succession remains rare. We tracked ten individually identified colonies of Fragaria viridis over 15 years during spontaneous succession in a loess old-field in Hungary, annually measuring maximum colony diameter and estimating cover. F. viridis is a common species of the adjacent ancient loess meadow steppe, and its successful expansion was a target of old-field regeneration. Early-colonizers formed significantly larger colonies (up to 1,000 cm diameter, 26 m2 cover) and expanded rapidly during the first decade, then plateaued after year ten, likely due to intensified mid-succession competition. Late-colonizers remained small (128 cm diameter, 0.2 m2 cover on average in the final year), being approximately eight times smaller and 130 times less dense. Statistical models revealed highly significant effects of establishment timing and time since abandonment. Annual clonal growth rates proved strongly context-dependent, shaped by successional stage and establishment timing rather than being fixed species traits. Similar long-term studies across multiple species are needed to understand how clonal traits interact with successional dynamics and develop evidence-based restoration strategies.