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

Ecology and Evolution, Journal Year: 2023, Volume and Issue: 13(3)

Published: March 1, 2023

Intraspecific variability (IV) has been proposed to explain species coexistence in diverse communities. Assuming, sometimes implicitly, that conspecific individuals can perform differently the same environment and IV increases niche overlap, previous studies have found contrasting results regarding effect of on coexistence. We aim at showing large observed data does not mean are necessarily different their response role high-dimensional environmental variation determining largely remained unexplored forest plant first used a simulation experiment where an individual attribute is derived from model, representing "perfect knowledge" environment, illustrate how result "imperfect environment. Second, using growth clonal

Language: Английский

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Widespread analytical pitfalls in empirical coexistence studies and a checklist for improving their statistical robustness

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: July 4, 2023

Abstract Modern Coexistence Theory (MCT) offers a conceptually straightforward approach for connecting empirical observations with an elegant theoretical framework, gaining popularity rapidly over the past decade. However, beneath this surface-level simplicity lie various assumptions and subjective choices made during data analysis. These can lead researchers to draw qualitatively different conclusions from same set of experiments. As predictions MCT studies are often treated as outcomes, many readers reviewers may not be familiar framework’s assumptions, there is particular risk “researcher degrees freedom” inflating confidence in results, thereby affecting reproducibility predictive power. To tackle these concerns, we introduce checklist consisting statistical best-practices promote more robust applications MCT. Our recommendations organised into four categories: presentation sharing raw data, testing model fits, managing uncertainty associated coefficients, incorporating coexistence predictions. We surveyed published 15 years discovered high degree variation level rigour adherence best practices. present case illustrate dependence results on seemingly innocuous among competition structure error distributions, which some cases reversed predicted outcomes. demonstrate how analytical approaches profoundly alter interpretation experimental underscoring importance carefully considering thoroughly justifying each step taken analysis pathway. serves resource authors alike, providing guidance strengthen foundation analyses. field shifts descriptive, trailblazing phase stage consolidation, emphasise need caution when building upon findings earlier studies. ensure that progress ecological based reliable evidence, it crucial subject our predictions, conclusions, generalizability rigorous assessment than currently trend.

Language: Английский

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The influence of sample size and sampling design on estimating population‐level intra specific trait variation (ITV) along environmental gradients

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(9)

Published: Sept. 1, 2024

Abstract Understanding the relationship between intraspecific trait variability (ITV) and its biotic abiotic drivers is crucial for advancing population community ecology. Despite importance, there a lack of guidance on how to effectively sample ITV reduce bias in resulting inferences. In this study, we explored size affects estimation population‐level ITV, distribution sizes along an environmental gradient (i.e., sampling design) impacts probabilities committing Type I II errors. We investigated error using four simulated scenarios which varied design strength ITV‐environment relationships. also applied simulation empirical data populations small mammal, Peromyscus maniculatus across gradients latitude temperature at sites National Ecological Observatory Network (NEON) continental United States. found that larger rates both silico populations. Furthermore, influence detecting relationships depends are distributed gradients. High correlations environment result greater error, while weak ITV–environmental showed high probabilities. Therefore, having large even most robust studying These findings shed light complex interplay among size, design,

Language: Английский

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Does deterministic coexistence theory matter in a finite world?

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2018, Volume and Issue: unknown

Published: March 28, 2018

Abstract Contemporary studies of species coexistence are underpinned by deterministic models that assume competing have continuous (i.e. non-integer) densities, live in infinitely large landscapes, and coexist over infinite time horizons. By contrast, nature composed discrete individuals subject to demographic stochasticity, occur habitats finite size where extinctions time. One consequence these discrepancies is metrics derived from theory may be unreliable predictors the duration nature. These include invasion growth rates niche fitness differences, which now commonly applied theoretical empirical coexistence. Here we test efficacy on a world. We introduce new computational methods estimate times stochastic counterparts classic competition. Importantly, parameterized this model using experimental field data for 90 pairwise combinations 18 annual plants, allowing us derive biologically-informed estimates natural system. Strikingly, find expected deterministically coexist, habitat sizes containing only tens predicted greater than 1, 000 years. also explain 60% variation intrinsic times, reinforcing their general usefulness However, integrating information both species’ equilibrium population could most (> 99%) explained. This integration achieved with demographically uncoupled single solely determined sizes. Moreover, because complex relationship between overlap/fitness differences sizes, increasing overlap did not always result decreasing as would predict. Nevertheless, our results tend support informed use understanding coexistence, while highlighting need incorporate addition rates.

Language: Английский

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Maintenance of Intraspecific Diversity in Response to Species Competition and Nutrient Fluctuations

Microorganisms, Journal Year: 2022, Volume and Issue: 10(1), P. 113 - 113

Published: Jan. 6, 2022

Intraspecific diversity is a substantial part of biodiversity, yet little known about its maintenance. Understanding mechanisms intraspecific shifts provides realistic detail how phytoplankton communities evolve to new environmental conditions, process especially important in times climate change. Here, we aimed identify factors that maintain genotype and link the observed change measured morpho-functional traits Vmax cell size species genotypes. In an experimental setup, two Emiliania huxleyi Chaetoceros affinis, each consisting nine genotypes, were cultivated separately together under different fluctuation nutrient regimes. Their composition was assessed after 49 91 days, Shannon’s index calculated on level. We found higher can be maintained presence competitor, provided it has proportion total biovolume. Both regime showed species-specific effects structured sorting C. affinis. While could relate with traits, only partly explained. The context dependency maintenance suggests evolutionary potential better understood, if studied more natural settings including fluctuations competition.

Language: Английский

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Complexity vs linearity: relations between functional traits in a heterotrophic protist

BMC Ecology and Evolution, Journal Year: 2023, Volume and Issue: 23(1)

Published: Jan. 11, 2023

Abstract Background Functional traits are phenotypic that affect an organism’s performance and shape ecosystem-level processes. The main challenge when using functional to quantify biodiversity is choose which ones measure since effort money limited. As one way of dealing with this, Hodgson et al. (Oikos 85:282, 1999) introduced the idea two types traits, soft easy quick quantify, hard directly linked ecosystem functioning but difficult measure. If a link exists between then could use as proxy for meaningful assessment biodiversity. However, this framework based on assumptions: (1) must be tightly connected allow reliable prediction other; (2) relationship monotonic linear detected by most common statistical techniques (e.g. model, PCA). Results Here we addressed those assumptions focusing six protist species Tetrahymena thermophila , vary both in their measurement difficulty meaningfulness. They were classified as: (morphological traits), intermediate (movement traits) (oxygen consumption population growth rate). We high number (> 60%) non-linear relations can explain low significant found models PCA analysis. Overall, these analyses did not detect any strong enough predict trait another, does imply there none. Conclusions Our results highlighted need critically assess among used proxies they aim reflect. A thorough whether such exist across communities necessary next step evaluate it possible take shortcut quantifying diversity collecting data easily measurable traits.

Language: Английский

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Wood density and leaf size jointly predict woody plant growth rates across (but not within) species along a steep precipitation gradient

Journal of Ecology, Journal Year: 2023, Volume and Issue: 112(2), P. 374 - 388

Published: Dec. 18, 2023

Abstract Functional traits have been proposed to define key dimensions of plant ecological strategies, but we lack consensus on whether can accurately predict demography. Despite theoretical expectations, it has challenging find consistent relationships between functional and growth. In this study, quantified inter‐ intraspecific trait variation (ITV) individual growth rates woody plants across a steep moisture gradient that varies 10‐fold in annual precipitation (350–3700 mm) southern Chile used hierarchical Bayesian model as function values. We show large‐leaved species with lower stem tissue density exhibited the fastest rates, these two highest proportion interspecific variation. Predictions improved considerably ( R 2 best increased from 0.28 0.49) when species‐level multiple their interactions were considered. The inclusion ITV, however, did not improve models rate. found trait–growth rate always levels biological organization; observed at level necessarily hold level. wood or leaf size direction gradient, economics weak site‐specific. Synthesis . Although using more than one predictions, successfully predicted (not within) species, which is whole‐plant carbon economy. assert are intimately linked ultimately describe continuum architecture economy covers syndromes.

Language: Английский

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Biogeographic patterns of micro-eukaryotic generalists and specialists and their effects on regional α-diversity at inter-oceanic scale

Marine Environmental Research, Journal Year: 2023, Volume and Issue: 193, P. 106261 - 106261

Published: Nov. 15, 2023

Language: Английский

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Top-down effects of intraspecific predator behavioral variation

Authorea (Authorea), Journal Year: 2023, Volume and Issue: unknown

Published: April 28, 2023

Among-individual variation in predator traits is ubiquitous nature. However, the role of intraspecific trait trophic dynamics has been seldom considered community ecology. This left unexplored a) to what degree does among-individual regulate prey populations and b) do these effects vary spatially. We address questions by examining how functional shapes communities across habitats varying structural complexity, field conditions for first time. manipulated Chinese mantis (Tenodera sinensis) density variability experimental patches old fields with habitat complexity quantified impacts on lower levels, specifically plant biomass. Our groups thus contrasted (six or twelve individuals) levels a key behavioral trait, activity level (movement an open field). metric was material. In complex at high densities, behaviorally variable decreased biomass 35.1%, while low arthropod 27.1%. Behavioral also changed composition. results are among demonstrate that can shape species-rich communities. Further, depend both complexity. Incorporating this important facet ecological diversity revealed normally unnoticed structure function food webs.

Language: Английский

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

Peer Community Journal, Journal Year: 2024, Volume and Issue: 4

Published: March 11, 2024

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

Language: Английский

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