Effects of species’ traits and data characteristics on distribution models of threatened invertebrates

Efectos de las características ecológicas y de los datos sobre los modelos de distribución de invertebrados protegidos La escasez de información sobre la distribución de las especies amenazadas impide el desarrollo de estrategias para su conservación, un problema particularmente importante en el caso de los invertebrados. En este trabajo se evalúan los efectos que las características ecológicas y de los datos ejercen sobre la precisión de los modelos de distribución de 20 especies ibéricas de invertebrados amenazados. Se encontró que la precisión en los modelos predictivos se ve afectada mayoritariamente por las características de los datos. Las especies que obtienen modelos de distribución más precisos son aquellas con mayor tamaño de muestra o menor área de ocurrencia relativa (ROA). Además, las especies relacionadas con hábitats difíciles de detectar mediante SIG, como las especies riparias, tienden a ser más difíciles de predecir. Palabras clave: Características ecológicas, Modelos de distribución de especies, Península ibérica, Precisión del modelo, Rango de distribución geográfica, Tamaño de muestra.The lack of information about the distribution of threatened species inhibits the development of strategies for their conservation. This is a particularly important problem when considering invertebrates. Here we evaluate the effects of species’ traits and data characteristics on the accuracy of species distribution models (SDM) of 20 threatened Iberian invertebrates. We found that the accuracy of the predictions was mostly affected by the characteristics of the data. Species whose distributions were most accurately modelled were those with a greater sample size or smaller relative occurrence area (ROA). Species in habitats that were difficult to detect using GIS data, such as riparian species, tended to be more difficult to predict. Key words: Ecological traits, Geographical distribution range, Iberian peninsula, Predictive accuracy, Sample size, Species distribution modelling.Efectos de las características ecológicas y de los datos sobre los modelos de distribución de invertebrados protegidos La escasez de información sobre la distribución de las especies amenazadas impide el desarrollo de estrategias para su conservación, un problema particularmente importante en el caso de los invertebrados. En este trabajo se evalúan los efectos que las características ecológicas y de los datos ejercen sobre la precisión de los modelos de distribución de 20 especies ibéricas de invertebrados amenazados. Se encontró que la precisión en los modelos predictivos se ve afectada mayoritariamente por las características de los datos. Las especies que obtienen modelos de distribución más precisos son aquellas con mayor tamaño de muestra o menor área de ocurrencia relativa (ROA). Además, las especies relacionadas con hábitats difíciles de detectar mediante SIG, como las especies riparias, tienden a ser más difíciles de predecir. Palabras clave: Características ecológicas, Modelos de distribución de especies, Península ibérica, Precisión del modelo, Rango de distribución geográfica, Tamaño de muestra

Assessing the functional relationship between dung beetle traits and dung removal, burial, and seedling emergence

The relationship between biodiversity and ecosystem functioning is often assessed through trait diversity. However, the relationship between traits and functions is typically assumed but seldom tested. We analyze the relationship between dung beetle traits and three ecological functions: dung removal, dung burial, and seedling emergence. We set up a laboratory experiment using nine Scarabaeidae species (three endocoprids, four paracoprids, and two telecoprids). We placed a sexual pair of beetles in each experimental unit, together with a mixture of dung and seeds, and measured the amount of dung removed and buried, burial depth, and the number of emerged seedlings. Sixteen morphological traits related to dung removal and burial were measured in each individual. Results indicate that these traits were related to dung beetle performance in dung removal and burial. Most traits were positively related to dung removal, indicating the existence of a general trait syndrome associated with dung manipulation and digging capability. Dung exploitation strategies did not provide further explanatory power. Seedling emergence showed a negative but weak relationship with dung burial amount and depth and species identity. This implies that specific differences in dung–soil interface activity may be important in secondary seed dispersal by dung beetles.info:eu-repo/semantics/publishedVersio

The Macaronesian province: patterns of species richness and endemism of arthropods

"[…]. The Macaronesian arthropod fauna displays a number of characteristics typical of oceanic islands, including a high degree of endemism, ranging from 19% for the Azores (Borges et al., 2005a), to 28% for Madeira (Borges et al., 2008a), 30% for Cape Verde (Arechavaleta etal., 2005) and 45% for the Canary Islands (Izquierdo et al., 2004; see Table I). The preponderance of endemic species has made the Macaronesian islands an outstanding area for studies of evolution and speciation, and arthropods from these islands have been the focus of particularly intensive investigation in the last ten years. Numerous biogeographic analyses of Macaronesian arthropod groups have provided valuable insights into the processes regulating species richness as well as the relationships among the region's endemics (e.g. Juan et al.,1996; Arnedo & Ribera, 1999; Borges & Brown, 1999; Emerson et al., 1999, 2006; Emerson & Oromí, 2005; Dimitrov et al., 2008; Borges & Hortal, 2009; Hochkirch & Görzig, 2009). Here we investigate the factors shaping arthropod species richness and patterns of endemism in the Macaronesian archipelagos, considering two levels of analysis: a) individual archipelagos of the Macaronesian region (except Madeira and Salvages due to their limited number of islands), and b) all the islands of the region altogether. We do this following the recently published works of Whittaker et al. (2008) and Borges & Hortal (2009), examining data sets for several taxa from the Macaronesian archipelagos. […]." (da Introdução)Fundação para a Ciência e a Tecnologia, Portugal

The ability of a host plant to associate with different symbiotic partners affects ectomycorrhizal functioning

Some plants that associate with ectomycorrhizal (ECM) fungi are also able to simultaneously establish symbiosis with other types of partners. The presence of alternative partners that may provide similar benefits may affect ECM functioning. Here we compared potential leucine-aminopeptidase (LA) and acid phosphatase (AP) enzyme activity (involved in N and P cycling, respectively) in ECM fungi of three hosts planted under the same conditions but differing in the type of partners: Pinus (ECM fungi only), Eucalyptus (ECM and arbuscular mycorrhizal -AM- fungi) and Acacia (ECM, AM fungi and rhizobial bacteria). We found that the ECM community on Acacia and Eucalyptus had higher potential AP activity than the Pinus community. The ECM community in Acacia also showed increased potential LA activity compared to Pinus. Morphotypes present in more than one host showed higher potential AP and LA activity when colonizing Acacia than when colonizing another host. Our results suggest that competition with AM fungi and rhizobial bacteria could promote increased ECM activity in Eucalyptus and Acacia. Alternatively, other host-related differences such as ECM community composition could also play a role. We found evidence for ECM physiological plasticity when colonizing different hosts, which might be key for adaptation to future climate scenarios.info:eu-repo/semantics/acceptedVersio

Species pool structure determines the level of generalism of island parasitoid faunas

Copyright © 2011 Blackwell Publishing Ltd.AIM To examine whether island parasitoid faunas are biased towards generalists when compared with the mainland and their species pool, and to evaluate the effects of climate, island characteristics and regional factors on the relative proportions of idiobionts (i.e. generalists) and koinobionts (i.e. specialists) of two parasitic wasp families, Braconidae and Ichneumonidae. LOCATION Seventy-three archipelagos distributed world-wide. METHODS We used data on the distribution and biology obtained from a digital catalogue and several literature sources. We related level of generalism, measured as the ratio between the number of idiobiont and koinobiont species, to climatic, physiographic and regional factors using generalized linear models. We compared models by means of Akaike weighting, and evaluated the spatial structure of their residuals. We used partial regressions to determine whether the final models account for all latitudinal structure in the level of generalism. RESULTS Islands host comparatively more idiobionts than continental areas. Although there is a latitudinal gradient in the level of generalism of island faunas correlating with both environmental factors and island characteristics, the most important determinant of island community structure is their source pool. This effect is stronger for ichneumonids, where generalism is higher in the Indomalayan region, arguably due to the higher diversity of endophytic hosts in its large rain forests. MAIN CONCLUSIONS The level of generalism of island parasitoid faunas is largely constrained by regional factors, namely by the structure of the species pool, which emphasizes the importance of including regional processes in our understanding of the functioning of ecological communities. The fact that generalist species are more predominant in islands with a large cover of rain forests pinpoints the importance of the indirect effects of ecological requirements on community structure, highlighting the complex nature of geographical gradients of diversity

Una estrategia para obtener regionalizaciones bióticas fiables a partir de datos incompletos: el caso de los escarabeidos (Coleoptera, Scarabaeinae) ibérico-baleares

A method to obtain regionalizations based in the organisms from incomplete distributional data is presented, using Iberian scarabaeine (Col., Scarabaeinae) as an example. A first ordination analysis was carried out using the well-sampled territorial units, where four faunistic axes were identified. Then, the scores of these axes were extrapolated to the whole Iberian territory by means of General Linear Modelling. A faunistic distance matrix was developed using the predicted values for the four axes. Using this matrix and the geographic distances among territorial units, a new matrix, reflecting both the compositional and geographic distances was obtained. This matrix was used to carry out the final classification of all the territory, where eight different faunistic regions were obtained. Finally, the results are briefly discussed, and their composition and local and regional richness are described.Se presenta un método para obtener regionalizaciones basadas en los organismos a partir de datos corológicos incompletos, utilizando como ejemplo los escarabeidos ibéricos (Col., Scarabaeinae). A partir de las unidades territoriales bien muestreadas, realizamos en primer lugar un análisis de ordenación, en el que se identificaron cuatro ejes faunísticos. Posteriormente, los valores de estos ejes se extrapolaron a todo el territorio ibérico mediante Modelos Lineales Generalizados. Con los valores predichos para estos ejes se desarrolló una matriz de distancias faunísticas. A partir de ella, y de las distancias geográficas entre unidades territoriales, se obtuvo una nueva matriz de distancias faunístico-geográficas. Esta matriz fue utilizada para realizar la clasificación final de todo el territorio, obteniéndose ocho regiones faunísticas diferentes. Finalmente, se comentan los resultados obtenidos, identificando las diferencias en su composición y riqueza regional y local

Distribución y patrones de diversidad de los Afódidos en la Comunidad de Madrid (Coleoptera, Scarabaeoidea, Aphodiidae, Aphodiinae y Psammodiinae)

In this work we present an updated checklist of the Aphodiidae (Coleoptera, Scarabaeoidea) from Comunidad de Madrid (Spain). In addition, the observed and potential distributions of the 70 species found in Madrid are mapped. The potential spatial distributions of species richness, rarity and endemism in this region are also mapped. Finally, we discuss briefly the origin of the observed patterns.En este trabajo se presenta un inventario actualizado de los Aphodiidae (Coleoptera, Scarabaeoidea) de la Comunidad de Madrid. Además, se presentan mapas de la distribución observada y potencial de las 70 especies encontradas en Madrid, así como de la distribución espacial de la riqueza, rareza, y endemicidad potencial en la región. Finalmente, se discute brevemente el origen de los patrones observados

Frontiers of Biogeography:Taking its place as a journal of choice for the publication of high quality biogeographical research articles

Through this editorial we seek your support and engagement as authors, readers and reviewers as we take the next steps in developing Frontiers of Biogeography as a leading international journal of biogeography and related subdisciplines. Here we make the case for submitting your next contribution to this journal: affordable, gold libre, open access, with the support of a disciplinarily-informed editorial and review team, which returns benefits to the biogeography community.Peer Reviewe

Adaptive colonization across a parasitism–mutualism gradient

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