The mossy north: An inverse latitudinal diversity gradient in European bryophytes

Rubén G. Mateo [et al.]It remains hotly debated whether latitudinal diversity gradients are common across taxonomic groups and whether a single mechanism can explain such gradients. Investigating species richness (SR) patterns of European land plants, we determine whether SR increases with decreasing latitude, as predicted by theory, and whether the assembly mechanisms differ among taxonomic groups. SR increases towards the south in spermatophytes, but towards the north in ferns and bryophytes. SR patterns in spermatophytes are consistent with their patterns of beta diversity, with high levels of nestedness and turnover in the north and in the south, respectively, indicating species exclusion towards the north and increased opportunities for speciation in the south. Liverworts exhibit the highest levels of nestedness, suggesting that they represent the most sensitive group to the impact of past climate change. Nevertheless, although the extent of liverwort species turnover in the south is substantially and significantly lower than in spermatophytes, liverworts share with the latter a higher nestedness in the north and a higher turn-over in the south, in contrast to mosses and ferns. The extent to which the similarity in the patterns displayed by spermatophytes and liverworts reflects a similar assembly mechanism remains, however, to be demonstrated.Peer reviewe

Algunas plantas de interés corológico para la comarca de la Sierra de San Vicente (Toledo, España)

Presentamos un total de 19 taxones nuevos o pocos representados en la flora vascular de la provincia de Toledo, que han sido recolectados en la comarca de la Sierra de San Vicente. De ellos 11 son primeras citas provinciales y 9 son segundas citas. Los plMateo, R. G. & Pajarón, S. 2004. Some plants of chorologyc interest in the Sierra de San Vicente area (Toledo, Spain). Bot. Complut. 28: 79-83. We present 19 taxa of vascular plants collected in the mountain region of San Vicente, in Toledo province. Among them, 11 are first provincial records and 9 of them are second provincial records. The specimens are kept in the herbarium MACB (Facultad de Ciencias Biológicas, Universidad Complutense, Madrid)

Simethis mattiazzi (Vandelli) Saccardo [(= S. planifolia (G.) Gren.], redescubierta para la flora de Castilla-La Mancha (España)

Durante los trabajos de seguimiento de la regeneración natural en la zona del Rodenal de Guadalajara afectada por las llamas en el verano de 2005, se localizó una numerosa población de Simethis mattiazzi (Vandelli) Saccardo

Population Genetic Structure and Demographic History of Primula fasciculata in Southwest China

Understanding the factors that drive the genetic structure of a species and its responses to past climatic changes is an important first step in modern population management. The response to the last glacial maximum (LGM) has been well studied, however, the effect of previous glaciation periods on plant demographic history is still not well studied. Here we investigated the population structure and demographic history of Primula fasciculata that widely occurs in the Hengduan Mountains and Qinghai-Tibetan Plateau. We obtained genomic data for 234 samples of the species using restriction site-associated DNA (RAD) sequencing and combined approximate Bayesian computation (ABC) and species distribution modeling (SDM) to evaluate the effects of multiple glaciation periods by testing several population divergence models and demographic scenarios. The analyses of population structure showed that P. fasciculata displays a striking population structure with six groups that could be identified genetically. Our ABC modeling suggested that the current groups diverged from ancestral populations located in the eastern Hengduan Mountains after the largest glaciation occurred in the region (~ 0.8-0.5 million years ago), which is consistent with the result of SDMs. Each current group has survived in different glacial refugia during the LGM and experienced expansions and/or bottlenecks since their divergence during or across the following Quaternary glacial cycles. Our study demonstrates the usefulness of population genomics for evaluating the effects of past climatic changes in alpine plant species with shallow population structure

Macroecology and ecoinformatics: evaluating the accuracy of the ecological niche models calibrated with species occurrence data with biases and/or errors

Hoy en día es común estudiar los patrones globales de biodiversidad a partir de las predicciones generadas por diferentes modelos de nicho ecológico. Habitualmente, estos modelos se calibran con datos procedentes de bases de datos de libre acceso (e.g. GBIF). Sin embargo, a pesar de la facilidad de descarga y de la accesibilidad de los datos, la información almacenada sobre las localidades donde están presentes las especies suele tener sesgos y errores. Estos problemas en los datos de calibración pueden modificar drásticamente las predicciones de los modelos y con ello pueden enmascarar los patrones macroecológicos reales. El objetivo de este trabajo es investigar qué métodos producen resultados más precisos cuando los datos de calibración incluyen sesgos y cuáles producen mejores resultados cuando los datos de calibración tienen, además de sesgos, errores. Para ello creado una especie virtual, hemos proyectado su distribución en la península ibérica, hemos muestreado su distribución de manera sesgada y hemos calibrado dos tipos de modelos de distribución (Bioclim y Maxent) con muestras de distintos tamaños. Nuestros resultados indican que cuando los datos sólo están sesgados, los resultados de Bioclim son mejores que los de Maxent. Sin embargo, Bioclim es extremadamente sensible a la presencia de errores en los datos de calibración. En estas situaciones, el comportamiento de Maxent es mucho más robusto y las predicciones que proporciona son más ajustadas.In spite of the biases and errors of the open access biodiversity databases we need to take advantage of the occurrences stored in those databases for analyzing the global patterns of biodiversity. Here, we aimed to test which modelling method produces better predictions when calibrated with data samples that have biases and errors. We tested two different methods, a complex one, Maxent, and a simple one, Bioclim. We created a virtual species, sampled its distribution with both, bias and errors, and calibrated the models with those samples. Results indicated that Bioclim produces better predictions than Maxent when calibrated with biased data sets. Bioclim did not overestimate the species’ range and it was able to produce accurate predictions even when calibrated with small and biased data samples (25-50 points). However, when wrong occurrences were included in the calibration samples, Bioclim over-predicted the species’ range. Our experiments indicated that in that case, Maxent predictions remained robust and provided accurate maps. Thus, if the calibration data samples have just biases, Bioclim provided better maps than Maxent. However, when samples have both, biases and wrong occurrences, Maxent model provided better results than Bioclim.Este trabajo se enmarca dentro de los proyectos: “Support of establishment, development and mobility of quality research teams at the Charles University” CZ.1.07/2.3.00/30.0022, financiado por la European Science Foundation y la República Checa (S.Varela); y “Potential effects of climate change on Natura 2000 conservation targets in Castilla-La Mancha (CLICHE)” (Ref. no.: POIC10-0311-0585), financiado por el gobierno de Castilla La-Mancha, España (S. Varela, R. G. Mateos, R. García-Valdés, and F. Fernández-González)

The European Union can afford greater ambition in the conservation of its threatened plants

The importance of Natura 2000 network for the conservation of natural habitats, wild flora and fauna at European level is undeniable. However, it may not have reached its full potential since the loss of biodiversity continues to increase year on year. Further on, a third of the plant species listed in the Habitats Directive to guide the declaration of European Union Natura 2000 network of protected areas is not threatened and there is broad agreement on the need to review and update the species list. Here, the effectiveness of Natura 2000 in the conservation of Spanish bryophytes and vascular plants included in the Habitats Directive Annex II is analysed and compared with the one offered to the species included in the Spanish Red Lists. Results show a remarkable coverage of Natura 2000 over the distribution areas of threatened species, thus providing an umbrella effect on these taxa. It confirms that the number of plant species in the Habitats Directive could be significantly extended without altering the current configuration of the network. This would allow the incorporation of scientific advances produced since the Habitats Directive was approved almost 30 years ago, and will contribute to the goals of the new European Biodiversity Strategy for 2030, such as to consider impacts caused by alien species, land use or climate changesThe Spanish Ministry of Science, Innovation and Universities supported J.C.M.S. through the Bioregions 2.0 project (CGL2017-86926-P

Approximate Bayesian Computation Reveals the Crucial Role of Oceanic Islands for the Assembly of Continental Biodiversity

The perceived low levels of genetic diversity, poor interspecific competitive and defensive ability, and loss of dispersal capacities of insular lineages have driven the view that oceanic islands are evolutionary dead ends. Focusing on the Atlantic bryophyte flora distributed across the archipelagos of the Azores, Madeira, the Canary Islands, Western Europe, and northwestern Africa, we used an integrative approach with species distribution modeling and population genetic analyses based on approximate Bayesian computation to determine whether this view applies to organisms with inherent high dispersal capacities. Genetic diversity was found to be higher in island than in continental populations, contributing to mounting evidence that, contrary to theoretical expectations, island populations are not necessarily genetically depauperate. Patterns of genetic variation among island and continental populations consistently fitted those simulated under a scenario of de novo foundation of continental populations from insular ancestors better than those expected if islands would represent a sink or a refugium of continental biodiversity. We, suggest that the northeastern Atlantic archipelagos have played a key role as a stepping stone for transoceanic migrants. Our results challenge the traditional notion that oceanic islands are the end of the colonization road and illustrate the significant role of oceanic islands as reservoirs of novel biodiversity for the assembly of continental flora

Thermal decomposition reaction of cis-6-phenyl-5,6-(2-phenyl-propilydene)- 3,3-tetramethylene-1,2,4-trioxacyclohexane in different solvents

The kinetics of the thermal decomposition reaction of cis-6-phenyl-5,6-(2- phenyl-propilydene)-3,3-tetramethylene-1,2,4-trioxacyclohexane (I) was investigated in the temperature range of 100-130°C in selected solvents of different physicochemical properties to evaluate a solvent effect on the reaction.Facultad de Ciencias Exacta

Assessing the effects of complexity in cross-temporal transferability of species distribution modelling predictions using palaeobotanical data

Valoración de la transferencia temporal de los modelos de distribución de especies para su aplicación en nuestros días utilizando datos paleobotánicos Corilus avellana y Alnus glutinosa

Do Stacked Species Distribution Models Reflect Altitudinal Diversity Patterns?

The objective of this study was to evaluate the performance of stacked species distribution models in predicting the alpha and gamma species diversity patterns of two important plant clades along elevation in the Andes. We modelled the distribution of the species in the Anthurium genus (53 species) and the Bromeliaceae family (89 species) using six modelling techniques. We combined all of the predictions for the same species in ensemble models based on two different criteria: the average of the rescaled predictions by all techniques and the average of the best techniques. The rescaled predictions were then reclassified into binary predictions (presence/absence). By stacking either the original predictions or binary predictions for both ensemble procedures, we obtained four different species richness models per taxa. The gamma and alpha diversity per elevation band (500 m) was also computed. To evaluate the prediction abilities for the four predictions of species richness and gamma diversity, the models were compared with the real data along an elevation gradient that was independently compiled by specialists. Finally, we also tested whether our richness models performed better than a null model of altitudinal changes of diversity based on the literature. Stacking of the ensemble prediction of the individual species models generated richness models that proved to be well correlated with the observed alpha diversity richness patterns along elevation and with the gamma diversity derived from the literature. Overall, these models tend to overpredict species richness. The use of the ensemble predictions from the species models built with different techniques seems very promising for modelling of species assemblages. Stacking of the binary models reduced the over-prediction, although more research is needed. The randomisation test proved to be a promising method for testing the performance of the stacked models, but other implementations may still be developed