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

Methods in Ecology and Evolution, Journal Year: 2024, Volume and Issue: 15(4), P. 594 - 611

Published: Feb. 28, 2024

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 predictions. We surveyed published 15 years discovered high degree variation level rigour adherence 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, generalisability rigorous assessment than currently trend.

Language: Английский

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Integrating eco‐evolutionary dynamics and modern coexistence theory

Ecology Letters, Journal Year: 2022, Volume and Issue: 25(10), P. 2091 - 2106

Published: Aug. 12, 2022

Community ecology typically assumes that competitive exclusion and species coexistence are unaffected by evolution on the time scale of ecological dynamics. However, recent studies suggest rapid operating concurrently with competition may enable coexistence. Such findings necessitate general theory incorporates contributions eco-evolutionary processes in parallel purely mechanisms provides metrics for quantifying role shaping outcomes both modelling empirical contexts. To foster development such theory, here we extend interpretation two principal modern theory-niche ability differences-to systems where competitors evolve. We define versions these considering how invading resident adapt to conspecific heterospecific competitors. show niche differences sums evolutionary processes, they accurately predict potential stable previous theoretical Finally, this frames assessments effects coexistence, work dynamics can be further integrated.

Language: Английский

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Accounting for demographic uncertainty increases predictions for species coexistence: A case study with annual plants

Ecology Letters, Journal Year: 2022, Volume and Issue: 25(7), P. 1618 - 1628

Published: May 28, 2022

Abstract Natural systems contain more complexity than is accounted for in models of modern coexistence theory. Coexistence modelling often disregards variation arising from stochasticity biological processes, heterogeneity among individuals and plasticity trait values. However, these unaccounted‐for sources uncertainty are likely to be ecologically important have the potential impact estimates coexistence. We applied a Bayesian framework data an annual plant community Western Australia propagate outcomes using invasion criterion ratio niche fitness differences. found accounting this altered predictions versus competitive exclusion 3 out 14 species pairs yielded probability priority effects additional pair. The propagation improves our ability predict accurately natural systems.

Language: Английский

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Does deterministic coexistence theory matter in a finite world?

Ecology, Journal Year: 2022, Volume and Issue: 104(1)

Published: Aug. 8, 2022

Abstract Contemporary studies of species coexistence are underpinned by deterministic models that assume competing have continuous (i.e., noninteger) 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 species’ 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. In this study, we tested efficacy on a world. We introduce new computational methods estimate times stochastic counterparts classic competition. Importantly, parameterized model using experimental field data for 90 pairwise combinations 18 annual plants, allowing us derive biologically informed estimates natural system. Strikingly, found expected deterministically coexist, community sizes containing only 10 had predicted more than 1000 years. also explained 60% variation intrinsic times, reinforcing their general usefulness However, integrating information both species' equilibrium population could most (>99%) explained. This integration was achieved with demographically uncoupled single‐species 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 use understanding while highlighting need incorporate addition rates.

Language: Английский

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Mechanisms of individual variation in large herbivore diets: Roles of spatial heterogeneity and state‐dependent foraging

Ecology, Journal Year: 2022, Volume and Issue: 104(2)

Published: Nov. 23, 2022

Abstract Many populations of consumers consist relatively specialized individuals that eat only a subset the foods consumed by population at large. Although ecological significance individual‐level diet variation is recognized, such difficult to document, and its underlying mechanisms are poorly understood. Optimal foraging theory provides useful framework for predicting how might select different diets, positing animals balance “opportunity cost” stopping an available food item against cost searching something more nutritious; composition should be contingent on distribution food, individual foragers selective when they have greater energy reserves invest in high‐quality foods. We tested these predicted niche differentiation quantifying environmental (resource heterogeneity) organismal (nutritional condition) determinants widespread browsing antelope (bushbuck, Tragelaphus sylvaticus ) African floodplain‐savanna ecosystem. quantified individuals' realized dietary niches (taxonomic richness composition) using DNA metabarcoding fecal samples collected repeatedly from 15 GPS‐collared (range 6–14 per individual, median 12). Bushbuck diets were structured spatial heterogeneity constrained condition. observed significant partitioning plants bushbuck both within between two adjacent habitat types (floodplain woodland). Individuals with home ranges closer together and/or had similar vegetation structure (measured LiDAR) ate supporting prediction heterogeneous resource promotes differentiation. good nutritional condition significantly narrower (fewer plant taxa), searched their intensively (intensity‐of‐use index), higher‐quality (percent digestible protein) than those poor condition, endogenous because can time nutritious Our results support predictions optimal about energetic basis provide potentially generalizable understanding width governed animal behavior physiology landscapes.

Language: Английский

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Inverse relationship between species competitiveness and intraspecific trait variability may enable species coexistence in experimental seedling communities

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 3, 2024

Abstract Theory suggests that intraspecific trait variability may promote species coexistence when competitively inferior have higher than their superior competitors. Here, we provide empirical evidence for this phenomenon in tree seedlings. We evaluated and plastic response of ten traits 6750 seedlings a three-year greenhouse experiment. While observed no relationship between competitiveness competition-free homogeneous environments, an inverse emerged under interspecific competition spatially heterogeneous environments. showed is driven by the species: Compared to counterparts, they exhibited greater increase variability, particularly fine-root traits, competition, environmental heterogeneity combination. Our findings contribute understanding how together structure plant communities.

Language: Английский

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How individual variation shapes ecological niches in two Pipistrellus bat species

Communications Biology, Journal Year: 2025, Volume and Issue: 8(1)

Published: March 27, 2025

Niche partitioning is a crucial mechanism explaining species coexistence and biodiversity; however, the role of individual variation less understood. As global changes reshuffle communities, understanding mechanisms vital. In this study, we use two co-occurring, morphologically similar bat species, Nathusius' pipistrelle (Pipistrellus nathusii) range-expanding Kuhl's (P. kuhlii), as models. We examine their niche across habitats time, considering variations by analysing spatio-temporal habitat selection 58 radio-tracked individuals. For resource assessment, metabarcoding guano samples. Our results show that in both exceeded species-level differences. exhibits greater between-individual variation, while shows stronger within-individual probably facilitating its expansion. This study emphasises significance investigating animal partitioning. It suggests contribution range expansion reshaping communities under change. A comprehensive analysis between reveals weak differences, but strong within

Language: Английский

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Quantifying the effects of intraspecific trait variation and interspecific trait correlations on interacting populations - a nonlinear averaging approach

Journal of Theoretical Biology, Journal Year: 2025, Volume and Issue: unknown, P. 112134 - 112134

Published: May 1, 2025

Interactions between two species, e.g. a predator species and prey can often be described as the sum of many individual-by-individual interactions whose outcomes depend on traits interacting individuals. These vary substantially among individuals in each do not always interact randomly, due to plastic responses shared environmental factor heterogeneous landscape. Here we investigate impact intraspecific trait variation (ITV) such interspecific correlations via nonlinear averaging. Building past models that integrate over an interaction kernel obtain impacts ITV, develop modeling framework allowing arbitrary interactions, with novel feature. Based key ingredients, joint distribution two-dimensional function, average parameters (e.g. predation rate) quantified numerically, approximated using insightful Taylor approximation, compared cases without ITV. We highlight applications our framework. First, study quantitative qualitative effects ITV simple predator-prey model show even absence evolution, make or break coexistence species. Second, use simulated field data for system how ecological estimated from empirical data.

Language: Английский

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Reexamining the storage effect: Why temporal variation in abiotic factors seems unlikely to cause coexistence

Ecological Monographs, Journal Year: 2023, Volume and Issue: 93(4)

Published: June 3, 2023

Abstract The temporal storage effect—that species coexist by partitioning abiotic niches that vary in time—is thought to be an important explanation for how coexist. However, empirical studies measure multiple mechanisms often find the effect is weak. We believe this mismatch because of a shortcoming theoretical models used study effect: while described as having just three requirements (partitioning variation, buffered population growth, and covariance between environment density‐dependence), make four assumptions, which are mathematically subtle but biologically important. In paper, we examine those assumptions. First, assume environmental variation leads rapid impact on density‐dependence. delays density‐dependence (including caused competition cohorts) weaken effect. Second, intraspecific almost identical interspecific competition. unless resource or predator virtually absent, then variation‐independent will overshadow benefits Third, even though there vast environment, equally adapted average (i.e., zero fitness‐differences). show fitness differences particularly problematic specializing temporally rare far less effective than other types niches. Finally, stochastic extinctions can ignored, invader growth determine coexistence. effects tend reduce mean persistence times, if rates positive. These results suggest assumptions needed strict: first second assumption relaxed, it greatly stabilizing mechanism; third fourth create diversity‐destroying may undermine real‐world communities—annual plants, tropical forests, iguanid lizards—and all communities violate This suggests probably not diversity most systems.

Language: Английский

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Local buffer mechanisms for population persistence

Trends in Ecology & Evolution, Journal Year: 2023, Volume and Issue: 38(11), P. 1051 - 1059

Published: Aug. 8, 2023

Language: Английский

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