loading page

Rethinking the nature of intraspecific variability and its consequences on species coexistence
  • +9
  • Camille Girard-Tercieux,
  • Isabelle Maréchaux,
  • Adam Clark,
  • James Clark,
  • Benoît Courbaud,
  • Claire Fortunel,
  • Joannes Guillemot,
  • Georges Kunster,
  • Guerric Le Maire,
  • Raphaël Pélissier,
  • Nadja Rüger,
  • Ghislain Vieilledent
Camille Girard-Tercieux
AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD
Author Profile
Isabelle Maréchaux
AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD
Author Profile
Adam Clark
University of Graz
Author Profile
James Clark
Duke University
Author Profile
Benoît Courbaud
Univ. Grenoble Alpes, INRAE, LESSEM
Author Profile
Claire Fortunel
AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD
Author Profile
Joannes Guillemot
Eco&Sols, Univ. Montpellier, CIRAD, INRAE, IRD, Institut Agro
Author Profile
Georges Kunster
Univ. Grenoble Alpes, INRAE, LESSEM
Author Profile
Guerric Le Maire
Eco&Sols, Univ. Montpellier, CIRAD, INRAE, IRD, Institut Agro
Author Profile
Raphaël Pélissier
AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD
Author Profile
Nadja Rüger
University of Leipzig
Author Profile
Ghislain Vieilledent
AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD,
Author Profile

Abstract

Context Intraspecific variability (IV) has been proposed to explain species coexistence in diverse communities. Assuming, sometimes implicitly, that conspecific individuals can perform differently in the same environment and that IV blurs species differences, previous studies have found contrasting results regarding the effect of IV on species coexistence. Objective We aim at showing that the larg IV observed in data does not mean that conspecific individuals are necessarily different in their response to the environment and that the role of high-dimensional environmental variation in determining IV has been largely underestimated in forest plant communities. Methods and Results We first used a simulation experiment where an individual attribute is derived from a high-dimensional model, representing “perfect knowledge” of individual response to the environment, to illustrate how a large observed IV can result from “imperfect knowledge” of the environment. Second, using growth data from clonal Eucalyptus plantations in Brazil, we estimated a major contribution of the environment in determining individual growth. Third, using tree growth data from long-term tropical forest inventories in French Guiana, Panama and India, we showed that tree growth in tropical forests is structured spatially and that despite a large observed IV at the population level, conspecific individuals perform more similarly locally than compared with heterospecific individuals. Synthesis As the number of environmental dimensions that are typically quantified is generally much lower than the actual number of environmental dimensions influencing individual attributes, a great part of observed IV might be misinterpreted as random variation across individuals when in fact it is environmentally-driven. This mis-representation has important consequences for inference about community dynamics. We emphasize that observed IV does not necessarily impact species coexistence per se but can reveal species response to high-dimensional environment, which is consistent with niche theory and the observation of the many differences between species in nature.
19 Jun 2022Submitted to Ecology and Evolution
20 Jun 2022Assigned to Editor
20 Jun 2022Submission Checks Completed
04 Jul 2022Reviewer(s) Assigned