Linking functional traits and demography to model species-rich communities

Loïc Chalmandrier,Daniel B Stouffer,Heike Lischke,Loïc Pellissier,Daniel C Laughlin,Maximilian Pichler,Florian Hartig

doi:10.1038/s41467-021-22630-1

Abstract

It has long been anticipated that relating functional traits to species demography would be a cornerstone for achieving large-scale predictability of ecological systems. If such a relationship existed, species demography could be modeled only by measuring functional traits, transforming our ability to predict states and dynamics of species-rich communities with process-based community models. Here, we introduce a new method that links empirical functional traits with the demographic parameters of a process-based model by calibrating a transfer function through inverse modeling. As a case study, we parameterize a modified Lotka–Volterra model of a high-diversity mountain grassland with static plant community and functional trait data only. The calibrated trait–demography relationships are amenable to ecological interpretation, and lead to species abundances that fit well to the observed community structure. We conclude that our new method offers a general solution to bridge the divide between trait data and process-based models in species-rich ecosystems.

Highlights

It has long been anticipated that relating functional traits to species demography would be a cornerstone for achieving large-scale predictability of ecological systems
By “community model”, we refer to any process-based model that predicts community structure and/or dynamics as a consequence of population-level processes such as growth, resource acquisition, mortality, and species interactions[8]
Model processes can be formulated across a range between phenomenological to more mechanistic descriptions[9], but are generally specified by demographic rate parameters that vary across species

Summary

Introduction

It has long been anticipated that relating functional traits to species demography would be a cornerstone for achieving large-scale predictability of ecological systems If such a relationship existed, species demography could be modeled only by measuring functional traits, transforming our ability to predict states and dynamics of species-rich communities with process-based community models. Model processes can be formulated across a range between phenomenological to more mechanistic descriptions[9], but are generally specified by demographic rate parameters that vary across species By predicting features such as species abundance, community structure, and dynamics over time, ecologists have argued that community models avoid many limitations of correlative models[10,11,12], and would represent an important step towards predictions of local biodiversity responses to environmental changes[13,14,15]. The approach assumes that the demographic parameters of the modeled species can be predicted from their functional traits[3]

Objectives

Methods

Results