For all researches, please visit our "Peer-reviewed publications" page.
Kennedy M, Lang P, Grimaldo J, Martins S, Bruce A, Moore I et al. (2017)
Niche-breadth of freshwater macrophytes occurring in tropical southern African rivers predicts species global latitudinal range
Aquatic Botany 136 21-30.
The study tested the hypothesis that measurement, using multivariate Principal Components Analysis (PCA), of the niche-breadth of river macrophyte species in southern tropical Africa, may predict their larger-scale biogeographical range. Two measures of niche-breadth were calculated for 44 riverine macrophyte species, from 20 families commonly occurring in Zambia, using an approach based on PCA ordination with 16 bio-physico-chemical input variables. These included altitude, stream order, stream flow, pH, conductivity and soluble reactive phosphate concentration (SRP). In the absence of additional chemical water quality data for Zambian rivers, invertebrate-based measures of general water quality were also used. These were benthic macroinvertebrate Average Score per Taxon (ASPT), and individual abundance of nine macroinvertebrate families with differing water quality tolerance, indicated by their Sensitivity Weightings within the Zambian Invertebrate Scoring System (ZISS). Macrophyte large-scale latitudinal range was derived from world geopositional records held by online databases, and additional records held by the authors. The two niche-breadth metrics divided the species into narrow-niche and intermediate/broad-niche categories, showing significant variation (from one or both of correlation and ANOVA test outcomes) in altitude, stream flow, conductivity, SRP, pH and ASPT, but not stream order. Macrophyte alpha-diversity (as a measure of number of individual niches co-existing per habitat) showed no significant relationship with individual species niche-breadth. Narrow-niche species included a higher proportion of Afrotropical endemics than did species with broader niche size. There were significant predictive relationships between macrophyte niche-breadth and latitudinal range of the target species at global and Afrotropical scales, but not for the Neotropics.
Keywords: Africa, Aquatic plants, Benthic macroinvertebrates, Freshwater ecology, Latitudinal distribution, Niche analysis, Rivers
Aguiar L, Bernard E, Ribeiro V, Machado R, Jones G (2016)
Global Ecology and Conservation 5 22-33.
Most extant species are survivors of the last climate change event 20,000 years ago. While past events took place over thousands of years, current climate change is occurring much faster, over a few decades. We modelled the potential distribution area of bat species in the Brazilian Cerrado, a Neotropical savannah, and assessed the potential impacts of climate change up to 2050 in two scenarios. First we evaluated what the impact on the distributions of bat species would be if they were unable to move to areas where climate conditions might be similar to current ones. The novelty of our paper is that, based on least-cost-path analyses, we identified potential corridors that could be managed now to mitigate potential impacts of climate change. Our results indicate that on average, in the future bat species would find similar climate conditions 281 km southeast from current regions. If bat species were not able to move to new suitable areas and were unable to adapt, then 36 species (31.6%) could lose >80% of their current distribution area, and five species will lose more than 98% of their distribution area in the Brazilian Cerrado. In contrast, if bat species are able to reach such areas, then the number of highly impacted species will be reduced to nine, with none of them likely to disappear from the Cerrado. We present measures that could be implemented immediately to mitigate future climate change impacts.
Keywords: Brazil, Brazilian Cerrado, Chiroptera, Conservation, Ecological niche models
Alexander N, Massei G, Wint W (2016)
The European Distribution of Sus Scrofa. Model Outputs from the Project Described within the Poster – Where are All the Boars? An Attempt to Gain a Continental Perspective
Open Health Data 4(1).
Wild boar is a host of a number of arthropod-vectored diseases and its numbers are on the rise in mainland Europe. The species potentially impacts ecosystems, humans and farming practices and so its distribution is of interest to policy makers in a number of fields beyond that of the primarily epidemiological goal of this study. Three statistical model outputs describing the distribution and abundance of the species Sus scrofa (Wild boar) are included in this data package. The extent of this dataset covers continental Europe. These data were presented as a poster  at the conference Genes, Ecosystems and Risk of Infection (GERI 2015). The first of the three models provide a European map presenting the probability of presence of Sus scrofa, which can be used to describe the likely geographical distribution of the species. The second and third models provide indices to help describe the likely abundance across the continent. The two indices include “the proportion of suitable habitat where presence is estimated” and a simple classification of boar abundance across Europe using quantiles of existing abundance data and proxies.
Keywords: Abundance, Distribution, Europe, Random Forest, Statistical modelling, Sus scrofa
Aliabadian M, Alaei-Kakhki N, Mirshamsi O, Nijman V, Roulin A (2016)
Biological Journal of the Linnean Society.
The existence of substantial morphological variation has resulted in the description of numerous subspecies of the cosmopolitan barn owl, Tyto alba. However, preliminary studies have revealed a high degree of genetic variation between Old and New World barn owls, suggesting that the T. alba complex may consist of several species. We present a comprehensive study of its taxonomy and propose a spatiotemporal framework to explain the origin and patterns of dispersal and diversification within these cosmopolitan owls. We used a Bayesian relaxed molecular clock approach to assess the timing of diversification. To evaluate the biogeographical pattern, we considered dispersal in addition to temporal connectivity between areas. Finally, we used ecological niche modelling to evaluate their ecological niches. Our phylogenetic analyses suggest that barn owls of the Old and New World show a high degree of genetic divergence, and the barn owls of South and South-east Asia (Tyto alba stertens and Tyto alba javanica) cluster with the Australian barn owl Tyto delicatula. We propose to treat the T. alba complex as three species: T. alba (Africa, Europe), Tyto furcata (New World), and Tyto javanica (Australasia). The dating analyses indicate that the early divergence among the species of the T. alba complex took place in the Middle Miocene and we hypothesize that a common ancestor of the T. alba complex lived in Africa. A potential scenario suggests that T. alba dispersed to Europe and south-western Asia during the interglacial periods of the Miocene/Pliocene, and dispersed into the New World either via an eastern Asian route or a western north Atlantic one.
Keywords: Abundance, Distribution, Europe, Random Forest, Statistical modelling, Sus scrofa
Araújo R, Assis J, Aguillar R, Airoldi L, Bárbara I, Bartsch I et al. (2016)
Biodiversity and Conservation 25(7) 1319-1348.
A comprehensive expert consultation was conducted in order to assess the status, trends and the most important drivers of change in the abundance and geographical distribution of kelp forests in European waters. This consultation included an on-line questionnaire, results from a workshop and data provided by a selected group of experts working on kelp forest mapping and eco-evolutionary research. Differences in status and trends according to geographical areas, species identity and small-scale variations within the same habitat where shown by assembling and mapping kelp distribution and trend data. Significant data gaps for some geographical regions, like the Mediterranean and the southern Iberian Peninsula, were also identified. The data used for this study confirmed a general trend with decreasing abundance of some native kelp species at their southern distributional range limits and increasing abundance in other parts of their distribution (Saccharina latissima and Saccorhiza polyschides). The expansion of the introduced species Undaria pinnatifida was also registered. Drivers of observed changes in kelp forests distribution and abundance were assessed using experts’ opinions. Multiple possible drivers were identified, including global warming, sea urchin grazing, harvesting, pollution and fishing pressure, and their impact varied between geographical areas. Overall, the results highlight major threats for these ecosystems but also opportunities for conservation. Major requirements to ensure adequate protection of coastal kelp ecosystems along European coastlines are discussed, based on the local to regional gaps detected in the study.
Keyword: Kelp forests Expert consultation Status and tempor
Bacon C, Look S, Gutiérrez-Pinto N, Antonelli A, Tan H, Kumar P et al. (2016)
Botanical Journal of the Linnean Society.
Four species are recognized in the understorey palm genus Johannesteijsmannia (Arecaceae), all of which occur in close geographical proximity in the Malay Peninsula. We hypothesize that overlapping distributions are maintained by a lack of gene flow among species and that segregation along morphological trait or environmental axes confers ecological divergence and, hence, defines species limits. Although some species have sympatric distributions, differentiation was detected among species in morphological and genetic data, corroborating current species delimitation. Differences in niche breadth were not found to explain the overlapping distribution and co-existence of Johannesteijsmannia spp. Four species formed over the last 3 Mya, showing that diversity accumulated within a short time frame and wide range expansion has not occurred, potentially due to a lack of time for dispersal or the evolution of traits to facilitate movement. An assessment of genetic diversity is presented and, as expected, the widest distribution in the genus harbours the highest genetic diversity.
Keywords: Malesia, Palmae, niche, phylogenetics, speciation
Ballesteros-Mejia L, Kitching I, Jetz W, Beck J (2016)
Putting insects on the map: Near-global variation in sphingid moth richness along spatial and environmental gradients
Despite their vast diversity and vital ecological role, insects are notoriously underrepresented in biogeography and conservation, and key broad-scale ecological hypotheses about them remain untested – largely due to generally incomplete and very coarse spatial distribution knowledge. Integrating records from publications, field work and natural history collections, we used a mixture of species distribution models and expert estimates to provide geographic distributions and emergent richness patterns for all ca. 1,000 sphingid moth species found outside the Americas in high spatial detail. Total sphingid moth richness, the first for a higher insect group to be documented at this scale, shows distinct maxima in the wet tropics of Africa and the Oriental with notable decay toward Australasia. Using multivariate models controlling for spatial autocorrelation, we found that primary productivity is the dominant environmental variable associated with moth richness, while temperature, contrary to our predictions, is an unexpectedly weak predictor. This is in stark contrast to the importance we identify for temperature as a niche variable of individual species. Despite divergent life histories, both main sub-groups of moths exhibit these relationships. Tribal-level deconstruction of richness and climatic niche patterns indicate idiosyncratic effects of biogeographic history for some of the less species-rich tribes, which in some cases exhibit distinct richness peaks away from the tropics. The study confirms, for a diverse insect group, overall richness associations of remarkable similarity to those documented for vertebrates and highlights the significant within-taxon structure that underpins emergent macroecological patterns. Results do not, however, meet predictions from vertebrate-derived hypotheses on how thermoregulation affects the strength of temperature-richness effects. Our study thus broadens the taxonomic focus in this data-deficient discourse. Our procedures of processing incomplete, scattered distribution data are a template for application to other taxa and regions.
Keywords: Distribution modelling, Lepidoptera, Productivity, Spatial scale, Sphingidae, Tropics
Bellard C, Leroy B, Thuiller W, Rysman J, Courchamp F (2016)
In this paper, we investigate how climate, land use, habitat characteristics, and socioeconomic activities contribute to predict the current potential distributions of the “100 among the world's worst invasive alien species”. We calculated the predictive power of each of the 41 variables for the 95 species including a large number of plants, vertebrates and invertebrates. We then calibrated the species distribution models with a set of appropriate variables for each invasive alien species to predict the potential distribution of these species and identify the major regions of origin of the invasive alien species. We found that climate variables were primarily predictors of the distribution of the global invaders studied. In addition, the habitat characteristics were also important predictors following by the socioeconomic variables such as the nearest distance to airports, seaports and human population density. We show that the potential areas at the highest risk of invasions from these species are located in Western Europe, Eastern United States, Central America, the eastern coast of Australia, and some Indonesian islands. We argue that these potential hotspots of invasions should be monitored in priority to prevent new invasions from these species. This study provides evidence of the importance of considering both habitat characteristics, socioeconomic and climate change factors for the current and future predictions of biological invasions.
Keywords: invasive species, socioeconomic, spatial risk
Benedict J, Smith S, Specht C, Collinson M, Leong-Škorničková J, Parkinson D et al. (2016)
Species diversity driven by morphological and ecological disparity: a case study of seeds of Zingiberales (bananas, gingers, and relatives).
AoB PLANTS plw063.
Phenotypic variation can be attributed to genetic heritability as well as biotic and abiotic factors. Across Zingiberales, there is a high variation in the number of species per clade and in phenotypic diversity. Factors contributing to this phenotypic variation have never been studied in a phylogenetic or ecological context. Seeds of 166 species from all eight families in Zingiberales were analyzed for 51 characters using synchrotron based 3D X-ray tomographic microscopy to determine phylogenetically informative characters and to understand the distribution of morphological disparity within the order. All families are distinguishable based on seed characters. Non-metric multidimensional scaling analyses show Zingiberaceae occupy the largest seed morphospace relative to the other families, and environmental analyses demonstrate that Zingiberaceae inhabit both temperate and tropical regions, while other Zingiberales are almost exclusively tropical. Temperate species do not cluster in morphospace nor do they share a common suite of character states. This suggests that the diversity seen is not driven by adaptation to temperate niches; rather, the morphological disparity seen likely reflects an underlying genetic plasticity that allowed Zingiberaceae to repeatedly colonize temperate environments. The notable morphoanatomical variety in Zingiberaceae seeds may account for their extraordinary ecological success and high species diversity as compared to other Zingiberales.
Keywords: Cannaceae, Costaceae, Heliconiaceae, Lowiaceae, Marantaceae, Musaceae, Strelitziaceae, Zingiberaceae
Branquart E, Brundu G, Buholzer S, Chapman D, Ehret P, Fried G et al. (2016)
A prioritization process for invasive alien plant species incorporating the requirements of EU Regulation no. 1143/2014
EPPO Bulletin 46(3) 603-617.
When faced with a large species pool of invasive or potentially invasive alien plants, prioritization is an essential prerequisite for focusing limited resources on species which inflict high impacts, have a high rate of spread and can be cost-effectively managed. The prioritization process as detailed within this paper is the first tool to assess species for priority for risk assessment (RA) in the European Union (EU) specifically designed to incorporate the requirements of EU Regulation no. 1143/2014. The prioritization process can be used for any plant species alien to the EU, whether currently present within the territory or absent. The purpose of the prioritization is to act as a preliminarily evaluation to determine which species have the highest priority for RA at the EU level and may eventually be proposed for inclusion in the list of invasive alien species of EU concern. The preliminary risk assessment stage (Stage 1), prioritizes species into one of four lists (EU List of Invasive Alien Plants, EU Observation List of Invasive Alien Plants, EU List of Minor Concern and the Residual List) based on their potential for spread coupled with impacts. The impacts on native species and ecosystem functions and related ecosystem services are emphasized in line with Article 4.3(c) of the Regulation. Only those species included in the EU List of Invasive Alien Plants proceed to Stage 2 where potential for further spread and establishment coupled with evaluating preventative and management actions is evaluated. The output of Stage 2 is to prioritize those species which have the highest priority for a RA at the EU level or should be considered under national measures which may involve a trade ban, cessation of cultivation, monitoring, control, containment or eradication. When considering alien plant species for the whole of the EPPO region, or for species under the Plant Health Regulation, the original EPPO prioritization process for invasive alien plants remains the optimum tool. Un processus de priorisation pour les plantes exotiques envahissantes, intégrant les exigences du Règlement UE No 1143/2014 Face à un grand nombre d'espèces de plantes exotiques envahissantes, ou potentiellement envahissantes, prioriser est un pré-requis afin de concentrer des ressources limitées sur les espèces à forts impacts, ayant un potentiel important de dissémination, et pouvant être gérées de façon efficace. Le processus de priorisation, tel que décrit dans le présent article, est le premier outil permettant d’évaluer le besoin de réaliser, en priorité, pour une espèce, une évaluation du risque pour l'Union Européenne (UE), et ce en cohérence avec les exigences du Règlement UE No 1143/2014. Ce processus de priorisation peut être appliqué à toute plante exotique au territoire de l’UE, qu'elle soit présente ou non sur ce territoire. L'objectif est de déterminer, lors d'une étape préliminaire, les espèces prioritaires pour lesquelles une évaluation du risque doit être conduite au niveau de l’UE, et qui pourraient éventuellement être proposées à l'inscription au sein de la liste des espèces exotiques envahissantes préoccupantes pour l’UE. L’évaluation du risque préliminaire (étape 1), classe les espèces au sein de l'une des quatre listes (liste des plantes exotiques envahissantes pour l’UE, liste d'observation des plantes exotiques envahissantes pour l’UE, liste d'importance réduite pour l’UE et liste résiduelle) sur la base de leur capacité de dissémination et de leurs impacts. Pour les impacts, l'accent est mis sur les espèces autochtones, sur les fonctions écosystémiques, ainsi que les services écosystémiques, en cohérence avec l'article 4.3(c) du Règlement UE. Seulement les espèces classées dans la liste des plantes exotiques envahissantes pour l’UE passent à la seconde étape. Au cours de cette étape sont analysés les risques de dissémination et d’établissement, ainsi que les mesures prophylactiques ou mesures de gestion possibles. L’étape 2 classe les espèces les plus prioritaires pour la réalisation d'une évaluation du risque au niveau de l’UE, ou qui devraient faire l'objet de mesures nationales telles que l'interdiction du commerce, l'arrêt de la culture, la surveillance, le contrôle, l'enrayement ou l’éradication. Le processus de priorisation OEPP d'origine reste néanmoins l'outil optimal lorsque le processus est à réaliser sur l'ensemble de la région OEPP, ou pour des espèces réglementées dans le cadre phytosanitaire.
Keywords: Cannaceae, Costaceae, Heliconiaceae, Lowiaceae, Marantaceae, Musaceae, Strelitziaceae, Zingiberaceae