Shortfalls in our understanding of the causes and consequences of functional and phylogenetic variation of freshwater communities across continents

[EN] Freshwater ecosystems harbour a disproportionately high biodiversity relative to their area, being also one of the most threatened ecosystem types worldwide. However, our capacity to design evidence-based conservation plans for this realm is restricted by all biodiversity shortfalls that have been recognized so far. In this context, the paucity of comparable field data and information on traits and phylogenies of freshwater organisms should be emphasized. Here, we highlight how increased knowledge could be gained and where we should aim at in research on the functional and phylogenetic features of freshwater communities. First, attempts to combine datasets from different sources should pay careful attention to data harmonization. Second, more effort should be focused on natural history observations on species habitats and life histories, providing the backbone of information for multi-trait databases. Third, fully resolved phylogenies would be required for deciphering the evolutionary relationships of freshwater organisms. Provided that these three hurdles can be overcome, conducting studies of local freshwater communities across continental spatial extents would pave the way for mapping functionally important ecosystems and evolutionarily valuable areas for the conservation of freshwater organisms and their habitatsS

Acoustically coupled volumes in the cathedrals of Murcia and Seville

Cathedrals are complex monuments built through the repetition of volumes separated by arches, vaults, and columns, in addition to a great variety of lateral chapels. In the so-called "Spanish mode" the choir is situated in the centre of the main nave and generally constitutes a more absorbent volume connected by an acoustically transparent opening with the rest of the cathedral. This space, together with the lateral chapels, can present the phenomenon of acoustic coupling. In this work, as a manifestation of this coupling, an analysis is performed, by means of standardised parameters and through the application of Bayesian methods, on the non-linearity of the energy decay curves of the impulse responses registered in situ in the Vélez Chapel of the Cathedral of Murcia, the Royal Chapel of the Cathedral of Seville, and in their respective choirsLas catedrales son monumentos complejos construidos mediante la repetición de volúmenes separados por arcos, bóvedas, columnas..., así como gran variedad de capillas laterales. En el denominado “modo español” el coro se sitúa en el centro de la nave principal y constituye generalmente un volumen más absorbente conectado mediante una apertura acústicamente transparente con el resto de la catedral. Este espacio, así como las capillas laterales, pueden presentar el fenómeno de acoplamiento acústico. En este trabajo, como manifestación de este acoplamiento, se analiza la no linealidad de las curvas de decaimiento energético mediante parámetros estandarizados y utilizando métodos bayesianos, de las respuestas al impulso registradas in situ en la Capilla de los Vélez de la Catedral de Murcia, la Capilla Real de la Catedral de Sevilla y en sus respectivos coro

Historical contingency via priority effects counteracts environmental change on metacommunity dynamics across decades

Community ecology has had a strong focus on single snapshots of species compositional variation in time. However, environmental change often occurs slowly at relatively broad spatio-temporal scales, which requires historically explicit assessments of long-term metacommunity dynamics, such as the order of species arrival during community assembly (i.e., priority effects), a theme that merits further empirical quantification. In this study, we applied the Bayesian inference scheme of Hierarchical Modeling of Species Communities together with information on functional traits and evolutionary dependencies to efficiently explore the question of how ecological communities are organized in space and time. To do this, we used a comprehensive time-series dataset from boreal lake plants and adopted the perspective that more sound conclusions on metacommunity dynamics can be gained from studies that consider a historically integrative approach over long timeframes. Our findings revealed that historical contingency via priority effects can profoundly shape community assembly under the influence of environmental change across decades (here, from the 1940s to the 2010s). Similarly, our results supported the existence of both positive and negative species-to-species associations in lake plants, suggesting that functional divergence can switch the inhibition–facilitation balance at the metacommunity level. Perhaps more importantly, this proof-of-concept study supports the notion that community ecology should include a historical perspective and suggests that ignoring priority effects may risk our ability to identify the true magnitude of change in present-day biotic communitiesS

Biotic interactions hold the key to understanding metacommunity organisation

Published by John Wiley & Sons Ltd on behalf of Nordic Society Oikos[EN] Biotic interactions are fundamental drivers governing biodiversity locally, yet their effects on geographical variation in community composition (i.e. incidence-based) and community structure (i.e. abundance-based) at regional scales remain controversial. Ecologists have only recently started to integrate different types of biotic interactions into community assembly in a spatial context, a theme that merits further empirical quantification. Here, we applied partial correlation networks to infer the strength of spatial dependencies between pairs of organismal groups and mapped the imprints of biotic interactions on the assembly of pond metacommunities. To do this, we used a comprehensive empirical dataset from Mediterranean landscapes and adopted the perspective that community assembly is best represented as a network of interacting organismal groups. Our results revealed that the co-variation among the beta diversities of multiple organismal groups is primarily driven by biotic interactions and, to a lesser extent, by the abiotic environment. These results suggest that ignoring biotic interactions may undermine our understanding of assembly mechanisms in spatially extensive areas and decrease the accuracy and performance of predictive models. We further found strong spatial dependencies in our analyses which can be interpreted as functional relationships among several pairs of organismal groups (e.g. macrophytes–macroinvertebrates, fish–zooplankton). Perhaps more importantly, our results support the notion that biotic interactions make crucial contributions to the species sorting paradigm of metacommunity theory and raise the question of whether these biologically-driven signals have been equally underappreciated in other aquatic and terrestrial ecosystems. Although more research is still required to empirically capture the importance of biotic interactions across ecosystems and at different spatial resolutions and extents, our findings may allow decision makers to better foresee the main consequences of human-driven impacts on inland waters, particularly those associated with the addition or removal of key speciesSIThis study was funded by the Univ. of León (LIMNO 417, Univ. of León, grant BB262). JGG, FGC and CFA appreciate financial support from the Spanish Ministry of Economy and Industry (project METAPONDS, grant CGL2017-84176R), the Junta of Castilla y León (grant LE004G18) and from the Fundación Biodiversidad (Spanish Ministry for Ecological Transition and Demographic Challenge). JA is supported (in part) by the Academy of Finland (grant 322652

Bridging population genetics and the metacommunity perspective to unravel the biogeographic processes shaping genetic differentiation of Myriophyllum alterniflorum DC.

[EN] The degree to which dispersal limitation interacts with environmental filtering has intrigued metacommunity ecologists and molecular biogeographers since the beginning of both research disciplines. Since genetic methods are superior to coarse proxies of dispersal, understanding how environmental and geographic factors influence population genetic structure is becoming a fundamental issue for population genetics and also one of the most challenging avenues for metacommunity ecology. In this study of the aquatic macrophyte Myriophyllum alterniflorum DC., we explored the spatial genetic variation of eleven populations from the Iberian Plateau by means of microsatellite loci, and examined if the results obtained through genetic methods match modern perspectives of metacommunity theory. To do this, we applied a combination of robust statistical routines including network analysis, causal modelling and multiple matrix regression with randomization. Our findings revealed that macrophyte populations clustered into genetic groups that mirrored their geographic distributions. Importantly, we found a significant correlation between genetic variation and geographic distance at the regional scale. By using effective (genetic) dispersal estimates, our results are broadly in line with recent findings from metacommunity theory and re-emphasize the need to go beyond the historically predominant paradigm of understanding environmental heterogeneity as the main force driving macrophyte diversity patternsSIWe thank all the members of the limnology group at the University of Leon for their assistance in field work. This research was funded by the Spanish Ministry of Science and Technology (project CL2017-84176R) and by the Junta of Castilla y León (project LE004G18

Palaeontology meets metacommunity ecology: The Maastrichtian dinosaur fossil record of North America as a case study.

Documenting the patterns and potential associated processes of ancient biotas has always been a central challenge in palaeontology. Over the last decades, intense debate has focused on the organisation of dinosaur–dominated communities, yet no general consensus has been reached on how these communities were organised in a spatial context and if primarily affected by abiotic or biotic agents. Here, we used analytical routines typically applied in metacommunity ecology to provide novel insights into dinosaurian distributions across the latest Cretaceous of North America. To do this, we combined fossil occurrences with functional, phylogenetic and palaeoenvironmental modelling, and adopted the perspective that more reasonable conclusions on palaeoecological reconstructions can be gained from studies that consider the organisation of biotas along ecological gradients at multiple spatial scales. Our results showed that dinosaurs were restricted in range to different parts of the Hell Creek Formation, prompting the recognition of discrete and compartmentalised faunal areas during the Maastrichtian at fine-grained scales, whereas taxa ranges formed quasi–nested groups when combining data from various geological formations across the Western Interior of North America. Although groups of dinosaurs had coincident range boundaries, their communities responded to multiple ecologically–important gradients when compensating for differences in sampling effort. Metacommunity structures of both ornithischians and theropods were correlated with climatic barriers and potential trophic relationships between herbivores and carnivores, thereby suggesting that dinosaurian faunas were shaped by physiological constraints and a combination of bottom-up and top-down forces across multiple spatial grains and extents.Additional Supporting files include the following Appendices: Appendix S1. Body mass distributions based on product partition models with Markov sampling computations. Appendix S2. Functional and phylogenetic features for each spatial scale and study clade. Appendix S3. R packages and statistical routines. Appendix S4. Elements of metacommunity structure for the conservative fixed–fixed null model. Appendix S5. Results for the forward selection of explanatory variables. Appendix S6. Results for ordinary least squares (OLS) regression models. Appendix S7. Results for commonality analysis (CA) for each spatial scale and study clade. Appendix S8. Measuring the spatial autocorrelation of OLS model residuals. The Excel file includes occurrence data, palaeoenvironmental reconstructions, and functional features: Sheets 1 and 2 contain raw information on each study site for the Hell Creek and other North American geological formations, respectively. Sheet 1 includes palaeoenvironmental information for the Hell Creek Formation (i.e. lithofacies -C, channel; FP, floodplain- and palaeotopography -m.a.s.l. after log-transformation). Raw PalaeoDEM data (Scotese and Wright, 2018) are also available here: https://www.earthbyte.org/paleodem-resource-scotese-and-wright-2018/ Sheet 2 contains raw information on the log-transformed palaeoenvironmental reconstructions for the Maastrichtian of North America (Palaeotopography -m.a.s.l., TempMean and TempSDann in K; Prec and PrecSDann in kgm-2). Raw palaeoclimate GCMs (Valdés et al., 2017) can also be obtained here: https://www.paleo.bristol.ac.uk/ummodel/scripts/papers/ Sheet 3 includes a taxon-specific classification into several functional guilds (see the main text for details): These files may be opened and edited in Excel. For details or further queries, please contact Jorge García-Girón ([email protected]). Funding provided by: University of León*Crossref Funder Registry ID: Award Number: 2017Funding provided by: Spanish Ministry of Economy and Industry*Crossref Funder Registry ID: Award Number: CGL2017–84176RFunding provided by: Junta de Castilla y LeónCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100014180Award Number: LE004G18Funding provided by: Academy of FinlandCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100002341Award Number: 331957Funding provided by: Academy of FinlandCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100002341Award Number: 322652Funding provided by: European Research Council Starting Grant*Crossref Funder Registry ID: Award Number: ERC StG 2017, 756226, PalMFunding provided by: University of LeónCrossref Funder Registry ID: Award Number: 2017Funding provided by: Spanish Ministry of Economy and IndustryCrossref Funder Registry ID: Award Number: CGL2017–84176RFunding provided by: European Research Council Starting GrantCrossref Funder Registry ID: Award Number: ERC StG 2017, 756226, PalMDinosaur occurrences for the Maastrichtian of North America were retrieved from the Palaeobiology Database on May 2020, using the taxon name 'Dinosauria' and a time span of 72.1 – 66.0 Ma. Critically, although studies on modern community associations are limited to relatively brief periods of sampling time, fossil assemblages are windows on the faunas of ancient worlds occurring within particular chronostratigraphic units (Benson et al. 2018). Although this coarse temporal resolution will undoubtedly confound the data (which is addressed in detail below), it would be problematic to subdivide the time bins further, not least because only a handful of fossil assemblages are sufficiently informative to provide confident community-level estimates so far (Vavrek & Larsson 2010). Additionally, due to an insufficient amount of comparative data within high–resolution time bins (Dean et al. 2020) and the inherent errors in radiometric dating (Gates et al. 2010), the creation of a more tightly constrained correlative window is presently impractical. Here, we only retained occurrences belonging to Ornithischia and Theropoda since these two clades were the most diverse and abundant non–avian dinosaur groups in the latest Cretaceous of North America (Brusatte et al. 2015). Generic–level identifications were used in our study, and all avian taxa were excluded when delineating community types to keep our data more comparable to previous works (e.g. Vavrek & Larsson 2010; Dean et al. 2020). While birds are phylogenetically part of the dinosaurian clade, the different habits and habitats of latest Cretaceous Avialae (either diving or volant taxa) separates these faunas enough from ground-dwelling dinosaurs to justify their functional distinction in the context of the communities modelled here (see Heino et al. 2015b for an example on present-day biotas). Although the value of generic taxonomic ranks in community analyses has been debated, palaeontologists have used generic–level clades to investigate distributional patterns and variation in community composition of fossil taxa (e.g. Vavrek & Larsson 2010; Chiarenza et al. 2019; Dean et al. 2020). Indeed, generic–level identifications are preferred over species taxonomic ranks in dinosaur palaeobiology studies as most dinosaur genera (c. 87%) are easily diagnosed and monospecific (Weishampel et al. 2004; Mannion et al. 2012). Moreover, genus-level and species–level diversity patterns generally appear to track each other for Mesozoic tetrapods (Barrett et al. 2009), and genera are more taxonomically stable than species for many groups (Robeck et al. 2000). Here, however, taxa with unclear genus identification were discarded (i.e. we did not incorporate 'cryptic' diversity represented by taxonomically undiagnostic fossil remains that potentially represent distinct taxa, nor we did infer ghost lineages based on phylogenetic diversity estimates; Barrett et al. 2009; Mannion et al. 2011), and so were collections lacking formational assignment. If questionable ages appeared (e.g. ages notably deviating from ages of other collections from the same formation), they were either revised or excluded. These data are an up–to–date record of North American dinosaur faunas and therefore incorporate new Late Cretaceous fossils discovered over the past few years. Overall, our pruned dataset comprised 43 dinosaur genera, and consisted of 11 formations across the WIB of North America and 17 well–sampled locations across the Hell Creek landscape. Palaeoclimatic general circulation model. In this study, we used palaeoclimatic model outputs (here, near-surface [1.5 m] mean annual temperature (TempMean), near-surface [1.5 m] annual temperature standard deviation (TempSDann), annual average precipitation (PrecMean) and annual precipitation standard deviation (PrecSDann)) from the fully coupled atmosphere-ocean GCM HadCM3L v. 4.5 Atmospheric–Ocean General Circulation Model (Valdes et al. 2017). More specifically, we followed the nomenclature of Valdes et al. (2017) and applied the HadCM3BL–M2.1aE version of the model. The conditions of the model simulations for the Maastrichtian consist of an atmospheric CO2 concentration of 1120 ppmv, which is within the range of uncertainty provided by the recent proxy pCO2 reconstructions of Foster et al. (2017). The model simulations were run for a total of 1422 years, and the climate variables used in our analyses were an annual average of the last 30 years of these simulations. HadCM3L has contributed to the Coupled Mode Intercomparison Project experiments demonstrating skill when it comes to reproducing present-day climates (Collins et al. 2001; Valdes et al. 2017) and has also been used for an array of different palaeoclimate evaluations during the Eocene (Lunt et al. 2012), the Oligocene (Li et al. 2018) and the Miocene (Bradshaw et al. 2012). Detailed information on this palaeoclimatic model, including large–scale circulation (and associated energy and momentum fluxes) and temporal fluctuations, as well as the impacts of fine-scale orographic features on climate signals, are available elsewhere (e.g. Lunt et al. 2016; Chiarenza et al. 2019). Palaeogeographical digital elevation models (DEMs). The Maastrichtian palaeogeography for this study is that of Scotese & Wright (2018), which has been compiled as a palaeo-digital elevation model to facilitate grid-based analyses. In brief, these maps were created from publicly available stratigraphic literature, supplemented by fieldwork, including lithology, palaeoenvironmental information and broad-scale facies identification. For large–scale analyses, these palaeogeographies were upscaled to the palaeoclimatic model resolution (3.75° x 2.5°). This means that topographic and bathymetric information was broadly conserved, as it was resolved at a lower resolution (see Chiarenza et al. 2019 for a similar approach). Functional features. Each dinosaur taxon was classified into several functional guilds based on body mass (very small, small, medium, large and very large), locomotor mode (bipeds, facultative bipeds –capable of both quadrupedal and bipedal motion– and quadrupeds) and trophic habits (carnivores, omnivores and herbivores, and for the latter, low and high browsers). Body mass is perhaps the single most important and meaningful functional trait for animals, as it ultimately affects many aspects of their biology including metabolic rates, mechanical constraints, ecological performance and lifestyle strategies related to feeding, locomotion and reproduction (Loeuille & Loreau 2006; Iossa et al. 2008). Here, we used body mass estimates (very small ≤ 10 kg; 10 kg 10000 kg; Noto & Grossman 2010) based on adult representatives from the comprehensive dataset of Benson et al. (2014), which provides a wide list of dinosaur taxa using the scaling relationship of limb bone robustness (stylopodial circumference; Campione & Evans 2012). To obtain a more comprehensive understanding of body mass distributions in our data, we further applied an inflection point criterion based on the Barry & Hartigan (1993) product partition model with Markov chain Monte Carlo (MCMC). More specifically, this algorithm used the posterior probability of changes over 10000 MCMC iterations, excluding the first 1000 as burn in, to distinguish among different body mass categories in the latest Cretaceous dinosaurs of North America. Interestingly, this Bayesian analysis roughly identified most of the original body mass categories used in our study, with each category broadly representing an order of magnitude (García–Girón et al. 2020b, appendix S1, fig. S1). Trophic habits refer to the food processing strategies and diet of an animal, and it generally includes three primary categories, i.e. carnivores, herbivores and omnivores. Further subdivisions depend on the biological knowledge of the morphology (e.g. teeth morphology and skull) and behaviour of the study organismal group. Here, we assigned herbivores to categories of browse height rather than plant type due to the virtually unknown nature of plant preferences in dinosaurs. More specifically, we roughly assigned a simple maximum browsing limit (low ≤ 2 m; high > 2 m) based on characters such as limb length and neck posture using Noto & Grossman (2010) and Mallon et al. (2013). We further divided locomotor mode into two major categories: quadrupeds and bipeds. For those taxa with intermediate axial and limb morphologies in proportions between those of bipeds and obligate quadrupeds (e.g. Hadrosauridae), we included an additional locomotor division, i.e. facultative bipeds (see Noto & Grossman, 2010 for a similar approach). For the following analyses, we applied the mixed–variables coefficient of distance (i.e. a generalisation of Gower's distance; Pavoine et al. 2009) to extract a functional distance matrix, which described the functional differences between all taxon pairs based on body mass, trophic habits and locomotor mode (e.g. Heino & Tolonen 2017). Thereafter, the pairwise output values for the functional distance matrix were synthesised into separate axes using principal coordinate analysis (PCO) and following Duarte et al. (2012). See the main text for References

DNA metabarcoding and morphological methods show complementary patterns in the metacommunity organization of lentic epiphytic diatoms

[EN] Diatoms are important organisms in freshwater ecosystems due to their position as primary producers and therefore, analyzing their assemblages provides relevant information on ecosystem functioning. Diatoms have historically been identified based on morphological traits, which is time-consuming and requires well-trained specialists. Nevertheless, DNA barcoding offers an alternative approach to overcome some limitations of the morphological method. Here, we assess if both approaches are comparable methods to study patterns and mechanisms (including environmental filtering and dispersal limitation) of epiphytic diatom metacommunities using a comprehensive dataset from 22 Mediterranean ponds at different taxonomic resolutions. We used a fragment of rbcL barcode gene combined with High-Throughput Sequencing to infer diatom community composition. The overall degree of correspondence between both approaches was assessed by Procrustean rotation analysis and Procrustean randomization tests, whereas the role of local environmental variables and geographical distances was studied using a comprehensive combination of BIOENV, Mantel tests and distance-based redundancy analysis. Our results showed a relatively poor correspondence in the compositional variation of diatom metacommunity between both approaches. We speculate that the incompleteness of the reference database and the bioinformatics processing are the biases most likely affecting the molecular approach, whereas the limited counting effort and the presence of cryptic species are presumably the major biases related with the morphological method. On the other hand, variation in diatom community composition detected with both approaches was strongly related to the environmental template, which may be related with the narrow community-environment relationships in diatoms. Nevertheless, we found no significant relationship between compositional variation and geographical distances. Overall, our work shows the complementary nature of both approaches and highlights the importance of DNA metabarcoding to address empirical research questions of community ecology in freshwaters, especially once the reference databases include most genotypes of occurring taxa and bioinformatics biases are overcomeSIThis study was supported by the project METAPONDS (CGL2017-84176R), grant by the Spanish Ministry of Economy and Industry, by the project BT-2019, grant by the Biodiversity Foundation and the Spanish Ministry for Ecological Transition and Demographic Challenge and by the project LE004G18, grant by the Junta of Castile and Leó

Human-induced loss of functional and phylogenetic diversity is mediated by concomitant deterministic processes in subtropical aquatic insect communities

[EN] Under a global change scenario, human-induced impacts alter multiple facets of river biodiversity (i.e., taxonomic, functional and phylogenetic). Hence, focusing on changes in community assembly and different diversity dimensions along anthropogenic impact gradients is of paramount importance for ecological research. Here, we classified stream sites into near-pristine (NP), moderately impacted (MI) and highly impacted (HI) categories based on a comprehensive anthropogenic impact score for the Hanjiang River Basin (China), and tested for differences in patterns of functional (FD) and phylogenetic diversity (PD). Our study suggests that NP sites showed higher FD and PD than impacted streams (MI and HI), with their communities being phylogenetically overdispersed and mostly shaped by random processes. Anthropogenically impacted sites mostly harbored closely related and functionally similar species, although the degree of clustering varied between NP, MI and HI streams, thereby confirming predictions that human activities contribute to the loss of evolutionary history and functional space in running waters. Importantly, we identified the influence of underlying deterministic mechanisms on the homogenization of both functional and phylogenetic facets of diversity. Similarly, NP sites exhibited the greatest proportion of evolutionarily distinct lineages, suggesting that anthropogenic impacts also threaten phylogenetically unique clades. Overall, this study contributed to a better understanding of multiple diversity patterns in aquatic insect communities by generating new empirical evidence of human-induced degradation of subtropical stream ecosystems in ChinaS

Una propuesta de tutorización dinámica en grupos a través del juego

[ES] En este dossier presentamos una experiencia docente gamificada con el objetivo de estimular la implicación y motivación de los alumnos hacia las tutorías grupales, en un contexto de consolidación generalizada de la evaluación continua en la Enseñanza Superior. Nuestra propuesta persigue invertir la dinámica de la tutorización por grupos para incorporar el juego como estrategia activa y así mejorar los indicadores de asistencia y participación en estas sesiones presenciales. Los estudiantes a los que se ha destinado esta acción educativa llevan mostrando una creciente desidia hacia las tutorías de la asignatura en cuestión, en un contexto curricular en el que otras materias con las que ésta se solapa en el tiempo adquieren mayor protagonismo por su dificultad intrínseca. Más concretamente, esta comunicación se centra en una asignatura obligatoria adscrita al Área de Ecología de la Universidad de León y su aplicación se circunscribe (aunque no estrictamente) al ámbito general de las ciencias biológicas y ambientales. En síntesis, utilizando diferentes dinámicas de juego basadas en concursos, nuestros resultados cuantitativos sugieren que incorporar el juego en las tutorías de grupo se configura como una herramienta notablemente eficiente a la hora de incrementar el rendimiento académico de los alumnos. Esta mejora en su desempeño vino acompañada por una disminución concomitante en la tasa de abandono de las sesiones de tutoría a lo largo del curso académico, sobre todo en estudiantes repetidores. Concluimos que la tutorización dinámica en grupos a través del juego hace que los alumnos participen con más entrega y dedicación en estas sesiones presenciales, facilitando la labor de seguimiento del docente en lo referido a la evolución de la curva de aprendizaje de sus pupilos

Little evidence of range size conservatism in freshwater plants across two continents

[EN] Aim: Range size conservatism suggests that closely-related species maintain geographic ranges of similar extent. However, consensus regarding this suggestion has not been reached. To shed more light on this phenomenon, we studied freshwater plant range size conservatism, range overlap and environmental niche conservatism using congeneric species comparison in two continents. In addition, we investigated whether a phylogenetic signal is found in the range sizes of aquatic plants. Location: Europe and North America. Taxon: Freshwater plants. Methods: Across spatial resolutions (50 km2, 100 km2 and 200 km2), we applied Spearman correlations among 347 and 730 pairs of congeneric species in Europe and North America, respectively, and 63 pairs shared between them. In addition, Spearman correlations were used to evaluate how the degree of spatial overlap influences range sizes and which environmental variables explain variation in range sizes. Brownian evolutionary model was used to assess the phylogenetic signal in species range sizes. Results: We found no evidence of range size conservatism across spatial resolutions for any species and species shared between the continents. In addition, range sizes of more closely related species did not overlap geographically more than those of distantly related ones and no support for environmental niche conservatism was evidenced. Main conclusions: We found that aquatic plants show no range size conservatism in the Northern Hemisphere. This means that it is challenging to define different range sizes of freshwater plants through species traits. Furthermore, we are unable to predict unknown distributions of extant aquatic plant species based on known distributional attributes of closely related species. However, our findings suggest that the interpretations of previous investigations on the range sizes of aquatic plants remain valid due to lack of range size conservatism. These practical implications encourage studying range size conservatism across realms and regions, especially for understudied organismal groupsS