CSR ecological strategies explain plant species dominance in the Gandoman wetland, Iran

Wetlands are highly productive ecosystems in which vegetation plays a crucial role in primary productivity and biodiversity. Between July 2016 and October 2017, plant species were sampled in plots within the Gandoman wetland, Chaharmahal and Bakhtiari Province, Iran. The geographical distribution and life forms of species were recorded using R aunkiaer’s system, and leaf traits—including leaf area (LA), leaf fresh weight (LFW), and leaf dry weight (LDW)—were measured. The CSR (Competitor, Stress-tolerator, Ruderal) ecological strategies of 39 species were assessed using the StrateFy method. Floristic analysis indicated that Iran–Turanian (36.8%) and multi-regional species (23.7%) were the most abundant. A total of 14 CSR strategies were identified, with the competitive–stress-tolerator (CS) strategy being dominant. Cladium mariscus, with a competitive score of 60%, was the most representative species. Environmental gradients, particularly moisture variation and end-of-season livestock grazing, induced partial stress-tolerant adaptations. Vegetation dynamics revealed a gradual shift from competitive toward stress-tolerant strategies. Two ruderal species, Polygonum paronychioides and Setaria viridis, were confined to wetland margins, reflecting invasion from surrounding rangelands. These findings highlight the importance of understanding plant functional responses at the plot level for conservation, restoration, and sustainable wetland management. Effective grazing management is essential to prevent degradation and maintain the ecological integrity of Gandoman wetland.