• RLQ analysis
• CSR theory
• Crocus etruscus
• ecological strategies
• functional traits

Crocus etruscus Parl., an endemic geophyte of central Italy listed in Annex IV of the Habitat Directive and categorized as Near Threatened on the IUCN Red List, primarily inhabits sub-Mediterranean woodlands dominated by Castanea sativa Mill. or various oak species, including Quercus cerris L., Quercus petraea (Matt.) Liebl., and Quercus pubescens Willd. Understanding its ecological characteristics and interactions with biotic (i.e., plant communities) and abiotic (i.e., soil) factors is crucial for implementing specific management and conservation actions for C. etruscus. To this end, our study pursued two primary objectives: (1) Assessing the ecological strategy of C. etruscus across different sites; (2) Exploring the relationships between functional traits of C. etruscus, functional attributes of the plant community it inhabits, and soil parameters.
We investigated C. etruscus in 12 sites along a sea-inland gradient from the Tyrrhenian Sea to the Antiapennines. In each site, we conducted vegetation surveys to assess the presence and relative cover (%) of each plant species within 5 × 5 m plots. We collected leaves from C. etruscus, leaves from dominant species in the community (accounting for 80 % of cumulative cover), and soil samples from each plot. These leaves were used to determine Specific Leaf Area, Leaf Area, and Leaf Dry Matter Content, key functional traits employed to calculate the CSR strategy classifying plants into three main ecological strategies: Competitive, Stress-tolerant, and Ruderal. We utilized ANOVA and simple linear regressions to investigate the functional variability of C. etruscus and its associations with community and environmental attributes. Additionally, we employed RLQ analysis to explore relationships between functional attributes of the community and soil parameters.
Our findings indicate that in all sampled populations, the ecological strategy of C. etruscus was predominantly SC/CSR, with only one exception (SR/CSR). Surrounding communities primarily exhibited a mean ecological strategy of SR/CSR. Regression analysis suggested that soil characteristics, rather than macroclimatic and vegetation features, significantly influence the ecological strategy of C. etruscus. Specifically, a shift from a more acquisitive to a more conservative strategy was observed when transitioning from higher to lower nutrient availability.
RLQ analysis revealed a robust coordination between functional attributes of the communities and soil nutrient availability. These results can be further strengthened through additional studies that expand the experimental design, encompassing more sampling locations, diverse environmental variables, and the including of underground functional features of C. etruscus. Given recent shifts in the management of communities where C. etruscus thrives and ongoing climate change, alterations in these communities are anticipated. These results, combined with continuous monitoring, can enhance our understanding of these processes, and inform the adoption of conservation practices to safeguard both C. etruscus and the communities it inhabits.