IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Flowering phenology of co-occurring Asteraceae: a matter of climate, ecological interactions, plant attributes or of evolutionary relationships among species?
Autor/es:
TORRES, C.; GALETTO, L.
Revista:
ORGANISMS DIVERSITY & EVOLUTION
Editorial:
SPRINGER HEIDELBERG
Referencias:
Año: 2010 vol. 11 p. 9 - 19
ISSN:
1439-6092
Resumen:
Abstract We analyzed the flowering phenodynamics of 43Asteraceae species co-occurring in natural populations ofChaco Serrano forests in central Argentina. We exploredthe potential influence of factors such as photoperiod andclimate (variations in temperature, rainfall, and frost),animal-plant interactions (richness of floral visitors, frequencyof visits), some plant attributes (plant growth form,seed dispersal mechanism), and evolutionary relationshipsamong species on flowering phenodynamics. ClusterAnalysis (CA) and Principal Component Analysis (PCA)were the multivariate statistical methods used to analyzeemerging patterns associated with these co-occurringspecies. Null-model analyses were used to evaluate whetherflowering times are aggregated, segregated, or random.Results showed that flowering phenology was significantlycorrelated with the seasonal variation in temperature,photoperiod, rainfall, and frost. The multivariate statisticalmethods separated all the species in three groups: 1) specieswith short flowering time, large plant floral display, highfrequency of visits by a large number of species of floralvisitors, anemochorous fruits, and shrubby growth form,with a tendency to a segregated flowering pattern; 2)species with long flowering time, small plant floral display,low frequency of visits by few insect species, anemochorousfruits, and herbaceous growth form; and 3) specieswith long flowering time, small plant floral display,intermediate values for frequency of visits and number ofspecies of floral visitors, seed dispersal mechanisms otherthan anemochory, and herbaceous growth form. In addition,all but one species belonging to early-branching tribes(tribes phylogenetically close to the root of the Asteraceaetree) were grouped together and clustered in the sameregion of the two-dimensional PCA ordination. All speciesbelonging to the late-branching tribes (Asteroideae subfamilytribes) included in group 1 were separated from theother Asteroideae species in the PCA. In conclusion, itseems that climatic factors restrict the phenological periodof most species, and that plant attributes and taxonomicmembership are strongly related to flowering phenodynamicsin this group of Asteraceae studied.