Contrasting patterns of morphology, fluctuating asymmetry and leaf herbivory in three plant species of different successional stages of a tropical dry forest

Key message This paper shows the intraspecific plant responses in leaf morphology, herbivory and FA between mature and successional tropical dry forests, as well as the difficulty associated with understanding the relationship between FA and herbivory Understanding the processes that affect biotic interactions during secondary succession has implications for the maintenance of species diversity in the tropics. We studied the changes in leaf morphology, fluctuating asymmetry (FA) and herbivory in three dominant tropical dry forest plant species that occur in mature and secondary forests. We selected eight study sites: four in mature and four in successional forests. At each site, a plot of 20 x 50 m was established to characterize the vegetation structure and soil fertility. Subsequently, leaf morphology, FA and herbivory were measured in all individuals of Cordia elaeagnoides, C. alliodora and Achatocarpus gracilis with DBH >= 2.5 cm found in the plots. Plant abundance and plant height decreased in secondary forest, while the content of nitrates and phosphates increased in soil of secondary forests. Differences in leaf morphology between forest conditions were found for the three species. Total leaf area was higher in mature than in secondary forests for C. elaeagnoides and A. gracilis. An opposite pattern was found for C. alliodora. In both Cordia species, herbivory was higher in secondary than in mature forests. The opposite pattern was found for A. gracilis in secondary forests. For all the cases, FA was higher in mature forests than in secondary forests. Herbivory was positively correlated with FA in secondary forests in C. elaeganoides and in A. gracilis, whereas in C. alliodora herbivory was positively related with FA in mature forests. Overall, we detected changes in foliar morphology, fluctuating asymmetry and herbivory between mature and secondary forests, with a general pattern of higher FA levels in mature forests. Our findings illustrate the difficulty associated with understanding the relationship between FA and herbivory throughout the regeneration process in tropical dry forests due to the complexity of abiotic and biotic factors that can affect plant-herbivore interactions.