Turnover of plant trait hierarchies in simulated community assembly in response to fertility and disturbance

Plant ecologists have placed increasing emphasis on a functional understanding of vegetation. One way to gain insight into the assemblage of vegetation communities is to investigate plant trait responses to environmental gradients or experimental treatments. We present simulations of responses of suites of traits to treatments differing in soil resources and disturbance intensity, in order to construct a functional response hierarchy of traits. We focus on the traits specific leaf area (SLA), plant height, seed mass and life cycle. Though only four traits are varied, these traits are connected to other traits either through trade-offs (e.g. SLA with leaf life span and relative growth rate, seed mass with seed number) or allometric rules (e.g. above-ground biomass scales positively with below-ground biomass). Thus a wide range of plant life history is represented in the simulations. We simulated the assemblage of plant types composed of these traits at two fertility levels and four disturbance treatments, i.e. every 7 years, annually, or monthly mown, and annually ploughed. We present the results of a simulation using LEGOMODEL, an individual-based, spatially explicit, ecological field model and develop a novel method to construct a functional response hierarchy of traits.