Rethinking the nature of intraspecific variability and its consequences on species coexistence

Girard‐Tercieux, Camille; Maréchaux, Isabelle; Clark, Adam Thomas; Clark, James S.; Courbaud, Benoı̂t; Fortunel, Claire; Guillemot, Joannès; Künstler, Georges; Maire, Guerric le; Pélissier, Raphaël; Rüger, Nadja; Vieilledent, Ghislain

doi:10.1002/ece3.9860

Cited by 2 publications

(7 citation statements)

References 95 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results, although inevitably dependent on some modelling choices, provided evidence that using independent random draws is not a suitable approach to represent environmentally-driven intraspecific variability in most cases (Girard-Tercieux et al 2023). To do so, environment-species interactions should be better taken into account in models.…”

Section: Discussionmentioning

confidence: 87%

“…As shown here for spatial variation, this has profound consequences on the properties of the simulated community. Importantly, whatever its source, the spatio-temporal structure of individual variation is an emergent property of conspecific individuals responding more similarly to the environment than heterospecifics locally (Clark 2010; Girard-Tercieux et al 2023), an important condition for stable species coexistence (Chesson 2000).…”

Section: Discussionmentioning

confidence: 99%

“…Nicotra et al 2010; Napier et al 2023). However, while the intraspecific variation that is added in models as a noise around species means is not structured in space and time, IV, whether it is environmentally- or genetically-driven or both, is actually highly likely to be structured in space and time (Girard-Tercieux et al 2023). This structure could appear in space when IV results from spatially-structured environmental variables or from limited dispersion or local adaptation (Marrot et al 2021; Schmitt et al 2021; Westerband et al 2021).…”

Section: Discussionmentioning

confidence: 99%

“…Consequently, these observed differences do not necessarily mean that conspecific individuals substantially differ in their response to the environment. While it is widely accepted that environmentally-driven sIV is ubiquitous in natural communities (Nicotra et al 2010), the consequences of its substitution by random uIV on species coexistence and community dynamics remain to be thoroughly tested in models (Clark 2010; Girard-Tercieux et al 2023).…”

Section: Introductionmentioning

confidence: 99%

“…These studies have led to contrasting results however, letting the debate unresolved: IV could either (i) blur species differences, thus promoting transient or unstable coexistence (Vieilledent et al 2010; Crawford et al 2019), (ii) disproportionately advantage the strongest competitor, thus hindering coexistence (Courbaud et al 2012; Hart et al 2016), or (iii) promote coexistence in specific spatial configurations (Uriarte and Menge 2018). While a unifying framework differentiating whether IV affects niche traits or hierarchical traits has been recently proposed to explain these discrepancies (Stump et al 2022), a major assumption usually made in modelling studies, namely that IV is unstructured in space or time and can be represented by independent random draws around species-specific mean parameters, remains largely undiscussed (Girard-Tercieux et al 2023).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Girard‐Tercieux

Vieilledent

Clark

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

The role of intraspecific variability (IV) in shaping community dynamics has been intensively discussed over the past decade and modeling studies have played an important role in that respect. However, a major, but often implicit, assumption typically made by these studies, that IV can be represented by independent random draws around species-specific mean parameters, has largely remained undiscussed. A great part of observed IV is however structured in space or time, in particular when resulting from environmental dimensions that influence individual performance but are imperfectly characterized or unobserved in the field. To test this assumption, we designed a simulation experiment where we varied the level of knowledge of the environment in virtual communities, resulting in different relative importance of explained vs. unexplained individual variation in performance. We used a community dynamics simulator to generate communities where the unexplained individual variation is, or is not, added as an unstructured random noise. Communities simulated with unstructured IV never reached the community diversity and composition of those where all the variation is explained and structured (full knowledge model). This highlights that incorporating unstructured IV (i.e. a random noise) to account for unexplained (but structured) variation can be misleading. Also, comparing communities simulated with the same level of knowledge of the environment, but adding unstructured IV or not, we found that the effects of incorporating unstructured IV depended on the relative importance of structured versus unstructured IV. In particular, increasing the proportion of unstructured IV into the model moved from a positive to a negative effect on community diversity and similarity in composition with the full knowledge model. This suggests that it is crucial to account for the sources and structure of observed IV in real communities to better understand its effect on community assembly and properly include it in community dynamics models.

show abstract

Section: Discussionmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Girard‐Tercieux

Vieilledent

Clark

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Girard-Tercieux,

Vieilledent,

Clark

et al. 2024

Peer Community Journal

Self Cite

View full text Add to dashboard Cite

The role of intraspecific variability (IV) in shaping community dynamics and species coexistence has been intensively discussed over the past decade and modelling studies have played an important role in that respect. However, these studies often implicitly assume that IV can be represented by independent random draws around species-specific mean parameters. This major assumption has largely remained undiscussed, although a great part of observed IV is structured in space or time, in particular when environmental dimensions that influence individual performance are imperfectly characterised or unobserved in the field. To test the impact of this strong assumption on the outcome of community dynamics models, we designed a simulation experiment where we varied the level of knowledge of the environment in virtual communities, resulting in different relative importance of explained vs unexplained spatial individual variation in performance. We used a community dynamics simulator to generate communities where the unexplained individual variation is, or is not, added as an unstructured random noise. Communities simulated with unstructured IV never reached the community diversity and composition of those where all the variation was explained and structured (perfect knowledge model). This highlights that incorporating unstructured IV (i.e. a random noise) to account for unexplained (but structured) variation can lead to incorrect simulations of community dynamics. In addition, the effects of unstructured IV on community diversity and composition depended on the relative importance of structured vs unstructured IV, i.e. on the level of knowledge of the environment, which may partly explain the contrasting results of previous studies on the effect of IV on species coexistence. In particular, the effect of unstructured IV on community diversity was positive when the proportion of structured IV vs unstructured IV in the model was low, but negative when this proportion was high. This is because unstructured random noise can either limit the competitive exclusion of inferior competitors in low dimensions or destabilise tight niche partitioning in high dimension. Our study suggests that it is crucial to account for the sources and structure of observed IV in real communities to better understand its effect on community assembly and properly include it in community dynamics models.

show abstract

Rethinking the nature of intraspecific variability and its consequences on species coexistence

Cited by 2 publications

References 95 publications

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Beyond variance: simple random distributions are not a good proxy for intraspecific variability in systems with environmental structure

Contact Info

Product

Resources

About