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1.
J Anim Ecol ; 92(1): 44-65, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36443916

RESUMEN

Traits are key for understanding the environmental responses and ecological roles of organisms. Trait approaches to functional ecology are well established for plants, whereas consistent frameworks for animal groups are less developed. Here we suggest a framework for the study of the functional ecology of animals from a trait-based response-effect approach, using dung beetles as model system. Dung beetles are a key group of decomposers that are important for many ecosystem processes. The lack of a trait-based framework tailored to this group has limited the use of traits in dung beetle functional ecology. We review which dung beetle traits respond to the environment and affect ecosystem processes, covering the wide range of spatial, temporal and biological scales at which they are involved. Dung beetles show trait-based responses to variation in temperature, water, soil properties, trophic resources, light, vegetation structure, competition, predation and parasitism. Dung beetles' influence on ecosystem processes includes trait-mediated effects on nutrient cycling, bioturbation, plant growth, seed dispersal, other dung-based organisms and parasite transmission, as well as some cases of pollination and predation. We identify 66 dung beetle traits that are either response or effect traits, or both, pertaining to six main categories: morphology, feeding, reproduction, physiology, activity and movement. Several traits pertain to more than one category, in particular dung relocation behaviour during nesting or feeding. We also identify 136 trait-response and 77 trait-effect relationships in dung beetles. No response to environmental stressors nor effect over ecological processes were related with traits of a single category. This highlights the interrelationship between the traits shaping body-plans, the multi-functionality of traits, and their role linking responses to the environment and effects on the ecosystem. Despite current developments in dung beetle functional ecology, many knowledge gaps remain, and there are biases towards certain traits, functions, taxonomic groups and regions. Our framework provides the foundations for the thorough development of trait-based dung beetle ecology. It also serves as an example framework for other taxa.


Asunto(s)
Escarabajos , Ecosistema , Animales , Escarabajos/fisiología , Suelo/química , Plantas , Semillas , Biodiversidad , Ecología
2.
Ecol Lett ; 24(11): 2521-2523, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34510685

RESUMEN

Biddick & Burns (2021) proposed a null/neutral model that reproduces the island rule as a product of random drift. We agree that it is unnecessary to assume adaptive processes driving island dwarfing or gigantism, but several flaws make their approach unrealistic and thus unsuitable as a stochastic model for evolutionary size changes.


Asunto(s)
Evolución Biológica , Flujo Genético
3.
New Phytol ; 232(4): 1849-1862, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34455590

RESUMEN

The functioning of present ecosystems reflects deep evolutionary history of locally cooccurring species if their functional traits show high phylogenetic signal (PS). However, we do not understand what drives local PS. We hypothesize that local PS is high in undisturbed and stressful habitats, either due to ongoing local assembly of species that maintained ancestral traits, or to past evolutionary maintenance of ancestral traits within habitat species-pools, or to both. We quantified PS and diversity of 10 traits within 6704 local plant communities across 38 Dutch habitat types differing in disturbance or stress. Mean local PS varied 50-fold among habitat types, often independently of phylogenetic or trait diversity. Mean local PS decreased with disturbance but showed no consistent relationship to stress. Mean local PS exceeded species-pool PS, reflecting nonrandom subsampling from the pool. Disturbance or stress related more strongly to mean local than to species-pool PS. Disturbed habitats harbour species with evolutionary divergent trait values, probably driven by ongoing, local assembly of species: environmental fluctuations might maintain different trait values within lineages through an evolutionary storage effect. If functional traits do not reflect phylogeny, ecosystem functioning might not be contingent on the presence of particular lineages, and lineages might establish evolutionarily novel interactions.


Asunto(s)
Evolución Biológica , Ecosistema , Biodiversidad , Fenotipo , Filogenia , Plantas/genética
4.
Oecologia ; 195(3): 719-736, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33569745

RESUMEN

Species diversity varies in space and time. Temporal changes in the structure and dynamics of communities can occur at different scales. We investigated the temporal changes of dung beetle assemblages in the Amazonian region along seasons, years, and successional stages. We evaluated if assemblage structure changes between temporal scales and whether such changes affect the functional structure of communities. To achieve these goals, we sampled dung beetles using linear transects of baited pitfall traps during the dry and rainy seasons at two natural reserves in the Amazon region, each representing different time scales: one covering successional variations (80, 30, 5, and 1 years of recovery from logging) and the other one encompassing three consecutive years at two successional stages (20 and 10 years from logging). We used Generalized Linear Models to analyze interannual and successional changes in diversity, described assemblage structure with a NMDS, and examined compositional variation by partitioning beta diversity into its nestedness and turnover components. Abundance and richness decrease from the rainy to the dry season and towards earlier successional stages but do not differ between years. Assemblage diversity changes differently in interannual and successional scales. During succession, dung beetle assemblages change drastically, following a nested structure due to the appearance of species and functional groups in later successional stages. In contrast, functional group composition does not show consistent changes between years, displaying a turnover structure. This pattern supports non-deterministic changes in dung beetle assemblage structure along forest succession.


Asunto(s)
Escarabajos , Animales , Biodiversidad , Heces , Bosques , Estaciones del Año
5.
6.
Epidemiol Infect ; 148: e282, 2020 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-33183397

RESUMEN

One of the largest nationwide bursts of the first COVID-19 outbreak occurred in Spain, where infection expanded in densely populated areas through March 2020. We analyse the cumulative growth curves of reported cases and deaths in all Spain and two highly populated regions, Madrid and Catalonia, identifying changes and sudden shifts in their exponential growth rate through segmented Poisson regressions. We associate these breakpoints with a timeline of key events and containment measures, and data on policy stringency and citizen mobility. Results were largely consistent for infections and deaths in all territories, showing four major shifts involving 19-71% reductions in growth rates originating from infections before 3 March and on 5-8, 10-12 and 14-18 March, but no identifiable effect of the strengthened lockdown of 29-30 March. Changes in stringency and mobility were only associated to the latter two shifts, evidencing an early deceleration in COVID-19 spread associated to personal hygiene and social distancing recommendations, followed by a stronger decrease when lockdown was enforced, leading to the contention of the outbreak by mid-April. This highlights the importance of combining public health communication strategies and hard confinement measures to contain epidemics.


Asunto(s)
COVID-19/epidemiología , COVID-19/prevención & control , Distanciamiento Físico , Cuarentena/métodos , COVID-19/mortalidad , Humanos , Pandemias/prevención & control , Política Pública , SARS-CoV-2 , España/epidemiología
7.
Proc Biol Sci ; 286(1905): 20190291, 2019 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-31213189

RESUMEN

Although the description of bioregions dates back to the origin of biogeography, the processes originating their associated species pools have been seldom studied. Ancient historical events are thought to play a fundamental role in configuring bioregions, but the effects of more recent events on these regional biotas are largely unknown. We used a network approach to identify regional and sub-regional faunas of European Carabus beetles and developed a method to explore the relative contribution of dispersal barriers, niche similarities and phylogenetic history on their configuration. We identify a transition zone matching the limit of the ice sheets at the Last Glacial Maximum. While southern species pools are mostly separated by dispersal barriers, in the north species are mainly sorted by their environmental niches. Strikingly, most phylogenetic structuration of Carabus faunas occurred during the Pleistocene. Our results show how extreme recent historical events-such as Pleistocene climate cooling, rather than just deep-time evolutionary processes-can profoundly modify the composition and structure of geographical species pools.


Asunto(s)
Cambio Climático , Filogeografía , Animales , Biodiversidad , Evolución Biológica , Biota , Escarabajos , Ecosistema , Variación Genética , Cubierta de Hielo , Filogenia
8.
Biol Lett ; 15(10): 20190481, 2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31594495

RESUMEN

According to the island rule, small-bodied vertebrates will tend to evolve larger body size on islands, whereas the opposite happens to large-bodied species. This controversial pattern has been studied at the macroecological and biogeographical scales, but new developments in quantitative evolutionary genetics now allow studying the island rule from a mechanistic perspective. Here, we develop a simulation approach based on an individual-based model to model body size change on islands as a progressive adaptation to a moving optimum, determined by density-dependent population dynamics. We applied the model to evaluate body size differentiation in the pigmy extinct hominin Homo floresiensis, showing that dwarfing may have occurred in only about 360 generations (95% CI ranging from 150 to 675 generations). This result agrees with reports suggesting rapid dwarfing of large mammals on islands, as well as with the recent discovery that small-sized hominins lived in Flores as early as 700 kyr ago. Our simulations illustrate the power of analysing ecological and evolutionary patterns from an explicit quantitative genetics perspective.


Asunto(s)
Hominidae , Animales , Evolución Biológica , Tamaño Corporal , Fósiles , Indonesia , Islas , Mamíferos
9.
Proc Natl Acad Sci U S A ; 113(35): 9840-5, 2016 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-27535932

RESUMEN

The evolution of resource use in herbivores has been conceptualized as an analog of the theory of island biogeography, assuming that plant species are islands separated by phylogenetic distances. Despite its usefulness, this analogy has paradoxically led to neglecting real biogeographical processes in the study of macroevolutionary patterns of herbivore-plant interactions. Here we show that host use is mostly determined by the geographical cooccurrence of hosts and parasites in spider mites (Tetranychidae), a globally distributed group of plant parasites. Strikingly, geography accounts for most of the phylogenetic signal in host use by these parasites. Beyond geography, only evolutionary transitions among major plant lineages (i.e., gymnosperms, commelinids, and eudicots) shape resource use patterns in these herbivores. Still, even these barriers have been repeatedly overcome in evolutionary time, resulting in phylogenetically diverse parasite communities feeding on similar hosts. Therefore, our results imply that patterns of apparent evolutionary conservatism may largely be a byproduct of the geographic cooccurrence of hosts and parasites.


Asunto(s)
Coevolución Biológica , Interacciones Huésped-Parásitos , Modelos Genéticos , Plantas/clasificación , Tetranychidae/clasificación , Distribución Animal/fisiología , Animales , Geografía , Herbivoria/fisiología , Filogenia , Dispersión de las Plantas/fisiología , Plantas/genética , Plantas/parasitología , Tetranychidae/genética
10.
Oecologia ; 186(3): 805-816, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29349719

RESUMEN

Species richness is influenced by a nested set of environmental factors, but how do these factors interact across several scales? Our main aim is to disentangle the relative importance of environmental filters and the species pool on the richness of epiphytic bryophytes across spatial scales. To do so, we sampled epiphytic bryophytes in 43 oak forests across the northwest of the Iberian Peninsula. As predictors we used climate, descriptors of forest structure and micro-environment. We applied structural equation modeling to relate these variables with richness and cover at three scales: locality (forest), stand (three stands per forest), and sample (a quadrate in a tree). We assumed top-down relationships, so that large-scale variables influenced lower scale variables, and in which cover directly influenced richness. Richness at the next larger scale (locality to stand and stand to sample) is considered a surrogate of the species pool and included as a predictor of richness at the next smaller scale. Environmental variables explain locality richness, but as we decrease the spatial scale, its importance decreases and the dependence on species pool increases. In addition, we found unexpected bottom-up relationships (between micro-scale environment to locality richness). Our results point to the scale dependence of niche vs. neutral processes: niche processes are important at the locality (forest) scale, while neutral processes are significant at the small (sample) scale. We propose a modified conceptualization of the factors influencing biodiversity at different spatial scales by adding links across different scales (between micro-environment and locality-scale richness in our study).


Asunto(s)
Briófitas , Ecosistema , Biodiversidad , Europa (Continente) , Árboles
11.
Ann Bot ; 119(7): 1157-1167, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28334085

RESUMEN

Background and Aims: The geographical distributions of species are constrained by their ecological requirements. The aim of this work was to analyse the effects of environmental conditions, historical events and biogeographical constraints on the diversification of the three species of the western Mediterranean shrub genus Stauracanthus , which have a parapatric distribution in the Iberian Peninsula. Methods: Ecological niche factor analysis and generalized linear models were used to measure the response of all Stauracanthus species to the environmental gradients and map their potential distributions in the Iberian Peninsula. The bioclimatic niche overlap between the three species was determined by using Schoener's index. The genetic differentiation of the Iberian and northern African populations of Stauracanthus species was characterized with GenalEx. The effects on genetic distances of the most important environmental drivers were assessed through Mantel tests and non-metric multidimensional scaling. Key Results: The three Stauracanthus species show remarkably similar responses to climatic conditions. This supports the idea that all members of this recently diversified clade retain common adaptations to climate and consequently high levels of climatic niche overlap. This contrasts with the diverse edaphic requirements of Stauracanthus species. The populations of the S. genistoides-spectabilis clade grow on Miocene and Pliocene fine-textured sedimentary soils, whereas S. boivinii , the more genetically distant species, occurs on older and more coarse-textured sedimentary substrates. These patterns of diversification are largely consistent with a stochastic process of geographical range expansion and fragmentation coupled with niche evolution in the context of spatially complex environmental fluctuations. Conclusions: : The combined analysis of the distribution, realized environmental niche and phylogeographical relationships of parapatric species proposed in this work allows integration of the biogeographical, ecological and evolutionary processes driving the evolution of species adaptations and how they determine their current geographical ranges.


Asunto(s)
Clima , Ecosistema , Fabaceae/clasificación , Ecología , Fabaceae/fisiología , Filogenia , Filogeografía , España
12.
Am Nat ; 188(4): 398-410, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27622874

RESUMEN

Theory suggests that the structure of evolutionary history represented in a species community may affect its functioning, but phylogenetic diversity metrics do not allow for the identification of major differences in this structure. Here we propose a new metric, ELDERness (for Evolutionary Legacy of DivERsity) to estimate evolutionary branching patterns within communities by fitting a polynomial function to lineage-through-time (LTT) plots. We illustrate how real and simulated community branching patterns can be more correctly described by ELDERness and can successfully predict ecosystem functioning. In particular, the evolutionary history of branching patterns can be encapsulated by the parameters of third-order polynomial functions and further measured through only two parameters, the "ELDERness surfaces." These parameters captured variation in productivity of a grassland community better than existing phylogenetic diversity or diversification metrics and independent of species richness or presence of nitrogen fixers. Specifically, communities with small ELDERness surfaces (constant accumulation of lineages through time in LTT plots) were more productive, consistent with increased productivity resulting from complementary lineages combined with niche filling within lineages. Overall, while existing phylogenetic diversity metrics remain useful in many contexts, we suggest that our ELDERness approach better enables testing hypotheses that relate complex patterns of macroevolutionary history represented in local communities to ecosystem functioning.


Asunto(s)
Biodiversidad , Evolución Biológica , Ecosistema , Nitrógeno , Filogenia
13.
Glob Chang Biol ; 22(12): 3948-3959, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27002684

RESUMEN

Although it is generally recognized that global biodiversity is declining, few studies have examined long-term changes in multiple biodiversity dimensions simultaneously. In this study, we quantified and compared temporal changes in the abundance, taxonomic diversity, functional diversity, and phylogenetic diversity of bird assemblages, using roadside monitoring data of the North American Breeding Bird Survey from 1971 to 2010. We calculated 12 abundance and diversity metrics based on 5-year average abundances of 519 species for each of 768 monitoring routes. We did this for all bird species together as well as for four subgroups based on breeding habitat affinity (grassland, woodland, wetland, and shrubland breeders). The majority of the biodiversity metrics increased or remained constant over the study period, whereas the overall abundance of birds showed a pronounced decrease, primarily driven by declines of the most abundant species. These results highlight how stable or even increasing metrics of taxonomic, functional, or phylogenetic diversity may occur in parallel with substantial losses of individuals. We further found that patterns of change differed among the species subgroups, with both abundance and diversity increasing for woodland birds and decreasing for grassland breeders. The contrasting changes between abundance and diversity and among the breeding habitat groups underscore the relevance of a multifaceted approach to measuring biodiversity change. Our findings further stress the importance of monitoring the overall abundance of individuals in addition to metrics of taxonomic, functional, or phylogenetic diversity, thus confirming the importance of population abundance as an essential biodiversity variable.


Asunto(s)
Biodiversidad , Aves/clasificación , Filogenia , Animales , Ecosistema , América del Norte
14.
Evol Lett ; 8(3): 340-350, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38818421

RESUMEN

Adaptive colonization is a process wherein a colonizing population exhibits an adaptive change in response to a novel environment, which may be critical to its establishment. To date, theoretical models of adaptive colonization have been based on single-species introductions. However, given their pervasiveness, symbionts will frequently be co-introduced with their hosts to novel areas. We present an individual-based model to investigate adaptive colonization by hosts and their symbionts across a parasite-mutualist continuum. The host must adapt in order to establish itself in the novel habitat, and the symbiont must adapt to track evolutionary change in the host. First, we classify the qualitative shifts in the outcome that can potentially be driven by non-neutral effects of the symbiont-host interaction into three main types: parasite-driven co-extinction, parasite release, and mutualistic facilitation. Second, we provide a detailed description of a specific example for each type of shift. Third, we disentangle how the interplay between symbiont transmissibility, host migration, and selection strength determines: (a) which type of shift is more likely to occur and (b) the size of the interaction effects necessary to produce it. Overall, we demonstrate the crucial role of host and symbiont dispersal scales in shaping the impacts of parasitism and mutualism on adaptive colonization.

15.
Sci Rep ; 14(1): 24577, 2024 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-39426979

RESUMEN

Biological soil covers (BSCs) play a pivotal role in ecosystem functioning by enhancing soil stability, mediating nutrient cycling, and influencing soil hydrology. Recognized as ecosystem engineers, they can physically modify, maintain, or create habitats, facilitating plant community development. Through these intricate interactions, BSCs contribute significantly to ecological processes, highlighting their importance in the overall health and functionality of the ecosystems of the Iberian Peninsula. Here we present the results obtained from the contributions of the citizen scientists uploaded from November 2019 to January 2021 with eBryoSoil, an app that allows citizens to participate in mapping the BSC communities across the Iberian Peninsula. Here, we emphasize the importance of habitats and consequently, their interaction with climatic variables for the persistence of BSCs (lichens and bryophytes). Conservation efforts targeted at preserving diverse habitats are essential to ensure the continued presence of lichen and bryophyte communities. Despite challenges posed by the SARS-CoV-2 outbreak, this citizen science project demonstrated success in utilizing a specifically tailored app to gather valuable information on BSC communities, providing insights into their vulnerability to climate change. This program serves as an illustrative example of how citizen science can effectively identify and study vulnerable habitats, offering a blueprint for future studies focused on understudied organisms.


Asunto(s)
Ciencia Ciudadana , Cambio Climático , Ecosistema , Suelo , Suelo/química , Humanos , España , Briófitas/crecimiento & desarrollo , Líquenes/crecimiento & desarrollo , Conservación de los Recursos Naturales/métodos , Monitoreo del Ambiente/métodos , COVID-19/epidemiología
16.
Biodivers Data J ; 12: e106199, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38344169

RESUMEN

Background: Incomplete species inventories for Antarctica represent a key challenge for comprehensive ecological research and conservation in the region. Additionally, data required to understand population dynamics, rates of evolution, spatial ranges, functional traits, physiological tolerances and species interactions, all of which are fundamental to disentangle the different functional elements of Antarctic biodiversity, are mostly missing. However, much of the fauna, flora and microbiota in the emerged ice-free land of the continent have an uncertain presence and/or unresolved status, with entire biodiversity compendia of prokaryotic groups (e.g. bacteria) being missing. All the available biodiversity information requires consolidation, cross-validation, re-assessment and steady systematic inclusion in order to create a robust catalogue of biodiversity for the continent. New information: We compiled, completed and revised eukaryotic species inventories present in terrestrial and freshwater ecosystems in Antarctica in a new living database: terrANTALife (version 1.0). The database includes the first integration in a compendium for many groups of eukaryotic microorganisms. We also introduce a first catalogue of amplicon sequence variants (ASVs) of prokaryotic biodiversity. Available compendia and literature to date were searched for Antarctic terrestrial and freshwater species, integrated, taxonomically harmonised and curated by experts to create comprehensive checklists of Antarctic organisms. The final inventories comprises 470 animal species (including vertebrates, free-living invertebrates and parasites), 306 plants (including all Viridiplantae: embryophytes and green algae), 997 fungal species and 434 protists (sensu lato). We also provide a first account for many groups of microorganisms, including non-lichenised fungi and multiple groups of eukaryotic unicellular species (Stramenophila, Alveolata and Rhizaria (SAR), Chromists and Amoeba), jointly referred to as "protists". In addition, we identify 1753 bacterial (obtained from 348117 ASVs) and 34 archaeal genera (from 1848 ASVs), as well as, at least, 14 virus families. We formulate a basic tree of life in Antarctica with the main lineages listed in the region and their "known-accepted-species" numbers.

17.
Mol Ecol ; 22(20): 5053-5, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24118115

RESUMEN

Body size is one of the main regulators of the ecological characteristics of living organisms, including their biogeography. The 'ubiquity hypothesis' for microorganisms states that they are widely distributed, if not cosmopolitan, due to their small size that allows passive dispersal, in contrast to large organisms that are limited by geographical barriers in their active dispersal. Such idea, summarized in the tenet 'Everything is everywhere, but the environment selects', has driven most of the research in biogeography for microscopic organisms in the last decades, spurring a debate on whether there are fundamental differences in the biogeography of small and large organisms or not (Fenchel & Finlay 2004; Foissner 2008; Hortal 2011). The strong focus on the ubiquity hypothesis may have been often abused to provide a rationale for otherwise descriptive work on the spatial distribution of microscopic organisms; nevertheless, such focus also provides a framework to understand the mechanisms originating and maintaining biodiversity in space. The reliability of the analyses on unknown and understudied organisms is improving, and Heger et al. (2013) is a splendid example on small unicellular eukaryotes of what should be done to overcome the major problems and ambiguities that heated the debate on the ubiquity hypothesis.


Asunto(s)
Amoeba/genética , Clima , Variación Genética , Filogenia
18.
Ecol Evol ; 13(12): e10786, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38053793

RESUMEN

Biodiversity data records contain inaccuracies and biases. To overcome this limitation and establish robust geographic patterns, ecologists often curate records keeping those that are most suitable for their analyses. Yet, this choice is not straightforward and the outcome of the analysis may vary due to a trade-off between data quality and volume. This problem is particularly recurrent for less-studied groups with patchy sampling effort. The latitudinal pattern of mosses richness remains inconsistent across studies and these may emerge purely from sampling artefacts. Our main objective here is to assess the effect of different curation criteria on this spatial pattern in the Temperate Northern Hemisphere (above 20° latitude). We contrasted the geographical distribution of moss species records and the latitude-species richness relation obtained under different data curation scenarios. These scenarios comprehend five sources of taxonomical standardisations and eight data cleaning filters. The analyses are based on the selection of well-surveyed cells at 100 km cell resolution. The application of some 'data curation scenarios' severely affects the number of records selected for analysis and substantially changes the proportion of richness per cell. The sensitivity to data curation becomes detectable at regional and at the cell scales showing a large shift in the latitudinal richness peak in Europe, from 60° N to 45° N latitude, when only preserved specimens are selected and duplicates based on date of collection and coordinates are excluded. Our results stress the importance of justifying the criteria used for filtering biodiversity data retrieved from biodiversity databases to avoid detecting misleading patterns. Curating records under particular criteria compromises the information in some areas displaying different spatial information of mosses. This problem can be ameliorated if data filtering is combined with identifying well-surveyed cells, render relatively constant results under different combinations of filtering even for less well-known groups such as mosses.

19.
Ecol Evol ; 13(2): e9828, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36818530

RESUMEN

Species' environmental requirements and large-scale spatial and evolutionary processes determine the structure and composition of local communities. However, ecological interactions also have major effects on community assembly at landscape and local scales. We evaluate whether two xerophytic shrub communities occurring in SW Portugal follow constrained ecological assembly dynamics throughout large geographical extents, or their composition is rather driven by species' individualistic responses to environmental and macroecological constraints. Inland dune xerophytic shrub communities were characterized in 95 plots. Then, we described the main gradients of vegetation composition and assessed the relevance of biotic interactions. We also characterized the habitat suitability of the dominant species, Stauracanthus genistoides, and Ulex australis, to map the potential distribution of the xerophytic shrub communities. Finally, we examined the relationships between the vegetation gradients and a broad set of explanatory variables to identify the relative importance of each factor driving changes in community composition. We found that xerophytic shrubs follow uniform successional patterns throughout the whole geographical area studied, but each community responds differently to the main environmental gradients in each region. Soil organic matter is the main determinant of community variations in the northern region, Setúbal Peninsula, whereas aridity is so in the South/South-Western region. In contrast, in the central region, Comporta, the variation between S. genistoides and U. australis communities is explained mainly by aridity and temperature seasonality, followed by the individualistic responses of the dominant species and soil organic matter. Overall, these results indicate that, the relative importance of the main factors causing community-level responses varies according to regional processes and the suitability of the environmental conditions for the dominant species in these communities. These responses are also determined by intrinsic community mechanisms that result in a high degree of similarity in the gradient-driven community stages in different regions.

20.
Ecol Evol ; 13(4): e9950, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37113519

RESUMEN

The conversion of forests into open areas has large effects on the diversity and structure of native communities. The intensity of these effects may vary between regions, depending on the existence of native species adapted to open habitats in the regional pool or the time since habitat change.We assess the differences in species richness and functional diversity of dung beetle communities (Coleoptera: Scarabaeinae) between native forests and novel pasturelands of the Atlantic Forest and the Cerrado, two biomes with contrasting histories of human occupation in Brazil. We conducted standardized surveys in seven forest fragments and adjacent pastures in each region and measured 14 traits in individuals collected in each type of habitat at each particular site. We calculated functional richness, functional evenness, functional divergence, and community-weighted mean of traits for each area, and analyzed individual variation through nested variance decomposition and Trait Statistics.Communities were richer and more numerous at the Cerrado. We did not find any consistent relationship between functional diversity and forest conversion beyond the changes in species diversity. Although landscape changes were more recent at the Cerrado, the colonization of the new habitat by native species already adapted to open habitats lessens the functional loss in this biome. This indicates that habitat change's effects on trait diversity depend on the regional species pool rather than on time since land conversion.Forest conversion effects were primarily due to internal filtering. The effects of external filtering only appear at the intraspecific variance level, with contrasting differences between the Cerrado, where traits related to relocation behavior and size are selected, and the Atlantic Forest, where selection operates for traits related to relocation behavior and flight. These results evidence the importance of considering individual variance to address the responses of dung beetle communities to forest conversion.


A conversão de florestas em áreas abertas tem grandes efeitos sobre a diversidade e estrutura das comunidades nativas. A intensidade desses efeitos pode variar entre regiões, dependendo da existência de espécies nativas adaptadas a habitats abertos no pool regional ou do tempo de mudança de habitat.Avaliamos as diferenças na riqueza de espécies e diversidade funcional de comunidades de rola­bosta (Coleoptera: Scarabaeinae) entre florestas nativas e pastagens da Mata Atlântica e do Cerrado, dois biomas com histórias contrastantes de ocupação humana no Brasil. As comunidades foram amostradas em sete fragmentos florestais e pastagens adjacentes de cada região. Medimos quatorze caracteres de indivíduos coletados em cada ponto amostral de cada habitat e região. Posteriormente, calculamos a riqueza funcional, a equidade funcional, a divergência funcional e a média dos caracteres ponderada pela comunidade (CWM) para cada ponto amostral e analisamos a variação individual por meio de decomposição de variância aninhada e estatística T.As comunidades do Cerrado foram mais ricas e numerosas. Não encontramos nenhuma relação consistente entre diversidade funcional e conversão florestal além das mudanças na diversidade de espécies. Surpreendentemente, embora as mudanças na paisagem tenham sido mais recentes no Cerrado, a colonização do novo habitat por espécies nativas já adaptadas a habitats abertos diminuiu a perda funcional nos novos habitats deste bioma em comparação com a Mata Atlântica, onde as pastagens foram colonizadas apenas por espécies florestais generalistas e invasores exóticos. Isso indica que os efeitos da mudança de habitat na diversidade de caracteres dependem do conjunto regional de espécies e não do tempo desde a conversão da paisagem.Além disso, os efeitos da conversão florestal foram principalmente devidos à efeitos de filtros internos. Os efeitos de filtros externos apareceram apenas no nível de variância intraespecífica, com diferenças contrastantes entre o Cerrado, onde são selecionados caracteres relacionados ao comportamento de realocação e tamanho (Comprimento da Metatíbia, Comprimento, Volume e Largura do Pronoto) e a Mata Atlântica, onde a seleção opera em caracteres relacionadas ao comportamento de realocação e voo (Metatibia Length e Wing Load). Esses resultados evidenciam a importância de se considerar a variância individual para abordar as respostas das comunidades de rola­bostas à conversão florestal.

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