Seasonal variation in arbuscular mycorrhizal colonization in three Asteraceae species in a temperate secondary forest

Arbuscular mycorrhizal fungi (AMF) colonize plant roots, facilitating water absorption and the acquisition of nutrients essential for plant growth and reproduction. This association is present in all terrestrial ecosystems and is also common in secondary vegetation species. Despite their importance in various ecological processes in temperate forests, AMF patterns in the Asteraceae family, have been scarcely studied. There are few studies that explicitly link plant biological traits and seasonal edaphic variability to colonization dynamics. The objective of this research was to evaluate the existence of patterns in the arbuscular mycorrhizal association of three Asteraceae family species of secondary vegetation, Ageratina glabrata , Roldana angulifolia and Roldana barba-johannis , explained by some biological traits of the plant species and some edaphic factors of the site. Significant differences in AMF colonization were detected. Hyphae and spore colonization increased during the rainy season, while arbuscule frequency increased during the dry season. Generalized linear model results showed that species identity and its interaction with the site significantly affected plant height and coverage. R. barba-johannis exhibited a significant and positive correlation between coverage and arbuscule colonization. Canonical correspondence analysis revealed that fungal colonization was primarily associated with higher soil moisture, organic matter, and nutrient availability during the rainy season. Conversely, arbuscule colonization and plant growth during the dry season were related to light availability and ammonium levels. It was shown that AMF colonization of Asteraceae shrubs is strongly influenced by a combination of biological, edaphic and seasonal factors. • Three Asteraceae species exhibit different patterns of arbuscular mycorrhizal fungal (AMF) colonization. • In R. barba-johannis AMF spore colonization was correlated to plant height and canopy cover. • R. angulifolia has higher coverage and exhibits peak AMF activity during the rainy season. • A. glabrata exhibits higher dasometric factors but has weak associations with AMF. • Soil nutrients during the rainy season and light during the dry season shape AMF-plant dynamics.