Flowering timing prediction in Australian native understorey species (Acrotriche R.Br Ericaceae) using meteorological data

Abstract

The aim of this study was to determine the climatic influences on floral development for five members of the Australian native plant genus Acrotriche R.Br (Ericaceae). An observed period of summer floral dormancy suggests temperature is involved in flowering regulation in these species. Models were developed to determine temperature requirements associated with the likelihood of flowering occurring on any one day. To this end, the timing of flowering and meteorological data were collated for several sites, and multivariate logistic regressions performed to identify variables with a significant influence on flowering timing. The resultant models described a large amount of variation in flowering presence/absence, with (r2) values ranging from 0.72 to 0.79. Temperature was identified as influential on both floral development and flowering timing in each of the study species. The positive influence of short photoperiods on flowering in three of the winter flowering species was not surprising. However, the reporting here ofa significant association between interdiurnal temperature and flowering in one species is novel. The predictive power of the models was validated through a jackknife sequential recalculation approach, revealing strong positive and negative predictive ability for flowering for four of the five species. Applications of the models include assisting in determination of the suitability of areas for vegetation restoration and identifying the possible effects of climate change on flowering in the study species.