A key assumption of the use of ‘functional traits' in plant ecology is that these traits can be used to predict the fitness of species in terms of demographic rates and population performance. Thus, functional traits are often used to make predictions about how species will respond to environmental change, and about their capacity to recover following catastrophic events. However, the link between functional traits and demographic rates across plant species is by no means fully understood. Whilst associations between individual plant traits and vital rates have been previously demonstrated, these relationships explain relatively little of the observed variation in vital rates across species and environments.
Our research differs from previous work by focusing on the association between multivariate ‘trait syndromes’ and complete demographic strategies (i.e. combined schedules of growth, survivorship and reproduction) across a global suite of plant species. Specifically, we sourced matrix population models for approximately 100 plant species from the COMPADRE plant matrix database and matched these with data on plant functional traits from literature sources and collaborative plant trait databases (TRY and BIEN). Using a multivariate modelling framework we then assessed the extent to which life-history parameters derived from matrix population models can be predicted by combinations of plant traits.
Results/Conclusions
Preliminary findings demonstrate a strong association between trait syndromes and demographic strategies. Specifically, greater plant height, seed mass and stem density were associated with longer generation times and a greater age at maturity; whilst leaf economic traits were more strongly associated with plant longevity and fecundity metrics. However, residual variance in the models suggested a strong environmental signal, indicating that the relationship between functional traits and realized demographic strategies is likely to be strongly influenced by environmental context. To our knowledge, this is the first study to examine the multivariate association between plant traits and demographic strategies globally. Our results indicate that explicitly incorporating the multivariate nature of plant trait syndromes into ecological models will greatly improve our ability to make predictions about the demographic strategies and population responses of plant species.