Phenological dynamics of the invasive plant Acacia longifolia in Portugal
Acacia longifolia (Mimosoideae) is a bushy shrub or small tree native to South-East Australia. Introduced into Portugal at the beginning of the 20th century to stabilise sand dunes, A. longifolia has since become invasive and forms extensive monocultures in riparian habitats, along roadsides and mountain slopes. Timing, duration and abundance of vegetative and reproductive events and physiological and morphological adaptive strategies of species in using resources may play an important role in the success of invasive plant species. The current study examined the phenology of A. longifolia in four populations in North, Central and Southern Portugal. The distance between populations varied from 100 to 500 km. Climate data from March 2007 to March 2011 were compiled from records obtained from the weather station closest to each population. In 2008, phenological data was collected from each population by monitoring the presence or absence of both reproductive and vegetative (leaf initiation) phenophases. Significant variations in vegetative and reproductive phenophases were observed between populations. In the case of reproductive phenophases variation was observed across elevation or latitudinal gradients, with populations that were subject to more stressful climatic conditions advancing their flowering and fruiting. The occurrence of each phenophase was strongly associated with climatic conditions in the previous 5 – 12 months suggesting that plants receive phenological cues prior to this response. Temperature and irradiance were the most significant predictors of the phenological cycle of A. longifolia but precipitation also exerted a strong influence on budding and flowering.
Sources
Morais MC, Freitas H (2015) Phenological dynamics of the invasive plant Acacia longifolia in Portugal. Weed Research 55, 555-564.