Berzaghi, Fabio, Wright, Ian J., Kramer, Koen, Oddou-Muratorio, Sylvie, Bohn, Friedrich J., Reyer, Christopher P.O., Sabaté, Santiago, Sanders, Tanja G.M., and Hartig, Florian
Plant trait variability, emerging from eco-evolutionary dynamics that range from alleles to macroecological scales, is one of the most elusive, but possibly most consequential, aspects of biodiversity. Plasticity, epigenetics, and genetic diversity are major determinants of how plants will respond to climate change, yet these processes are rarely represented in current vegetation models. Here, we provide an overview of the challenges associated with understanding the causes and consequences of plant trait variability, and review current developments to include plasticity and evolutionary mechanisms in vegetation models. We also present a roadmap of research priorities to develop a next generation of vegetation models with flexible traits. Including trait variability in vegetation models is necessary to better represent biosphere responses to global change. Dynamic vegetation models are the main tools to assess climate change effects on terrestrial vegetation. Therefore, a realistic representation of biological processes in these models is of utmost importance. Intraspecific trait variability is ubiquitous in plants and, thus, the underlying processes causing it should be represented. Yet, trait variability is only used to a limited extent in current vegetation models. Empirical and theoretical studies make clear that intraspecific trait variability underpins evolutionary and plastic plant responses to environmental changes. We review progress towards 'next-generation' models that include evolutionary and plastic processes, including those explicitly representing genetic mechanisms. Modeling paradigms where plant diversity emerges mechanistically are necessary to understand both functional trade-offs (e.g., leaf and wood economics spectra) and spatial patterns of genetic and phenotypic variability as exposed by genomic and ecological data. [ABSTRACT FROM AUTHOR]