Concluding remarks
To obtain accurate estimates of phenotypic selection, it is essential to consider also selection via correlated traits (Lande and Arnold 1983). Yet, selection on the timing of life-cycle events is rarely estimated comprehensively enough to detect indirect selection via other phenological traits or correlational selection on trait combinations. Our results show that correlations between reproductive and vegetative phenology, in combination with contrasting selection on these two traits, can affect selection on flowering phenology, although the direction of selection on flowering time remained the same in our study. More generally, the results illustrate that selection on phenological traits can only be fully understood from the perspective of the seasonal development cycle. Yet, we still know little about the relationships among temporally correlated life history events, and the importance of these events for fitness. Insights into the extent to which selection on the timing of seasonal events is influenced by selection on temporally correlated events are also essential to understand long-term responses to anthropogenic climate change, as climate is likely to influence the phenotypic expression of sequential seasonal events as well as the optimal timing of these events (Li et al. 2016, Zohner et al. 2018, Mohan 2019).