Extracted from the Mendeley GBIF Public Library.
Alsos I, Ware C, Elven R (2015)
Increased human activity and climate change are expected to increase the numbers and impact of alien species in the Arctic, but knowledge of alien species is poor in most Arctic regions. Through field investigations over the last 10 years, and review of alien vascular plant records for the high Arctic Archipelago Svalbard over the past 130 years, we explored long term trends in persistence and phenology. In total, 448 observations of 105 taxa have been recorded from 28 sites. Recent surveys at 18 of these sites revealed that alien species had disappeared at half of them. Investigations at a further 49 sites characterised by former human activity and/or current tourist landing sites did not reveal any alien species. Patterns of alien species distribution suggest that greater alien species richness is more likely to be aligned with ongoing human inhabitation than sites of transient use. The probability of an alien species being in a more advanced phenological stage increased with higher mean July temperatures. As higher mean July temperatures are positively correlated with more recent year, the latter finding suggests a clear warming effect on the increased reproductive potential of alien plants, and thus an increased potential for spread in Svalbard. Given that both human activity and temperatures are expected to increase in the future, there is need to respond in policy and action to reduce the potential for further alien species introduction and spread in the Arctic.
Keywords: Alien Arctic, Climate change, Management, Non-native species, Phenology
Flø D, Krokene P, Økland B (2015)
Invasion potential of Agrilus planipennis and other Agrilus beetles in Europe: import pathways of deciduous wood chips and MaxEnt analyses of potential distribution areas
EPPO Bulletin 45(2) 259-268.
Bark- and wood-boring beetles in the genus Agrilus (Coleoptera: Buprestidae) can survive wood-chipping, and Agrilus planipennis has established in North America and European Russia with devastating impacts on forest ecosystems. The work presented in this paper combined import statistics of deciduous wood chips, Maximum entropy modelling (MaxEnt) of climatic similarities, and the distribution of potential tree hosts to predict the likelihood of four selected North American Agrilus species to become introduced and established in Europe. In agreement with the EU's energy-policy target of increased use of wood chips, there was a linear or exponential increase in European imports of deciduous wood chips during the past 10 years from countries harbouring potentially harmful Agrilus species. MaxEnt showed high environmental suitability in Europe for the four selected Agrilus species, particularly in Eastern Europe and European Russia for A. anxius, A. bilineatus and A. planipennis and in southern Europe for A. politus. Documented susceptible host trees are widely distributed in the predicted areas of Agrilus distribution in Europe, and these areas receive large quantities of deciduous wood chips from countries where these and other Agrilus species are present. Thus, it was concluded that the fundamental conditions for introduction and establishment of Agrilus species in Europe are in place. Potentiel d'invasion d'Agrilus planipennis et d'autres Agrilus en Europe: filières d'importation de copeaux de bois de feuillus et analyses MaxEnt des zones de répartition potentielles Les coléoptères de l'écorce et du bois du genre Agrilus (Coleoptera: Buprestidae) peuvent survivre aux processus de fabrication des copeaux de bois, et Agrilus planipennis s'est établi en Amérique du Nord et dans la partie européenne de la Russie avec des impacts dévastateurs sur les écosystèmes forestiers. Le travail présenté dans cet article combine des statistiques sur l'importation des copeaux de bois de feuillus, la modélisation du maximum d'entropie (MaxEnt) des similitudes climatiques, et la répartition des arbres-hôtes potentiels pour prévoir la probabilité d'introduction et d'établissement en Europe de quatre espèces d'Agrilus d'Amérique du Nord. L'objectif de la politique énergétique de l'UE d'accroissement de l'utilisation des copeaux de bois s'est accompagné d'une augmentation linéaire ou exponentielle des importations européennes de copeaux de bois de feuillus au cours des 10 dernières années en provenance de pays dans lesquels des espèces d'Agrilus potentiellement nuisibles sont présentes. La modélisation MaxEnt a montré que les conditions environnementales en Europe sont très favorables aux quatre espèces d'Agrilus étudiées, notamment en Europe de l'Est et dans la partie européenne de la Russie pour A. anxius, A. bilineatus et A. planipennis, et dans le sud de l'Europe pour A. politus. Les arbres-hôtes sensibles connus sont largement répandus dans les zones de répartition potentielle de ces Agrilus en Europe, et ces zones reçoivent de grandes quantités de copeaux de bois de feuillus provenant de pays où ces espèces et d'autres espèces d'Agrilus sont présentes. Ainsi, il est conclu que les conditions fondamentales de l'introduction et de l'établissement d'espèces d'Agrilus en Europe sont réunies.
Keywords: Alien Arctic, Climate change, Management, Non-native species, Phenology
Wasof S, Lenoir J, Aarrestad P, Alsos I, Armbruster W, Austrheim G et al. (2015)
Global Ecology and Biogeography.
Aim Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been separated for thousands of years. Location European Alps and Fennoscandia. Methods Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly disjunct populations and 358 species having either a contiguous or a patchy distribution with distant populations. First, we used species distribution modelling to test for a region effect on each species' climatic niche. Second, we quantified niche overlap and shifts in niche width (i.e. ecological amplitude) and position (i.e. ecological optimum) within a bi-dimensional climatic space. Results Only one species (3%) of the 31 species with strictly disjunct populations and 58 species (16%) of the 358 species with distant populations showed a region effect on their climatic niche. Niche overlap was higher for species with strictly disjunct populations than for species with distant populations and highest for arctic–alpine species. Climatic niches were, on average, wider and located towards warmer and wetter conditions in the Alps. Main conclusion Climatic niches seem to be generally conserved between populations that are separated between the Alps and Fennoscandia and have probably been so for 10,000–15,000 years. Therefore, the basic assumption of species distribution models that a species' climatic niche is constant in space and time – at least on time scales 104 years or less – seems to be largely valid for arctic–alpine plants.
Keywords: Alpine plants, arctic plants, climatic niche, disjunct distribution, distant populations, niche conservatism, niche optimum, niche overlap, niche width, species distribution modelling
Willis K, Seddon A, Long P, Jeffers E, Caithness N, Thurston M et al. (2015)
Remote assessment of locally important ecological features across landscapes: how representative of reality?
Ecological Applications 25(5) 1290-1302.
The local ecological footprinting tool (LEFT) uses globally available databases, modeling, and algorithms to remotely assess locally important ecological features across landscapes based on five criteria: biodiversity (beta-diversity), vulnerability (threatened species), fragmentation, connectivity, and resilience. This approach can be applied to terrestrial landscapes at a 300-m resolution within a given target area. Input is minimal (latitude and longitude) and output is a computer-generated report and series of maps that both individually and synthetically depict the relative value of each ecological criteria. A key question for any such tool, however, is how representative is the remotely obtained output compared to what is on the ground. Here, we present the results from comparing remotely- vs. field-generated outputs from the LEFT tool on two distinct study areas for beta-diversity and distribution of threatened species (vulnerability), the two fields computed by LEFT for which such an approach is f...
Keywords: beta-diversity, biodiversity evaluation, ecological footprint, ecological risk, field forecast verification, local ecological footprinting tool, local field data, threatened species, vulnerability, web-based landscape planning tool
Bendiksby M, Mazzoni S, Jørgensen M, Halvorsen R, Holien H (2014)
Combining genetic analyses of archived specimens with distribution modelling to explain the anomalous distribution of the rare lichen Staurolemma omphalarioides : long-distance dispersal or vicariance?
Journal of Biogeography.
Aim: The rare lichen species Staurolemma omphalarioides is known mainly from the lowlands and coastal areas of the Mediterranean region but has also been found in coastal parts of central Norway. Despite extensive search efforts by experts for more than half a century, the species has been found nowhere in the gap. Our aim is to identify the most plausible explanation for this anomalous distribution by combining genetic analysis of archived specimens with distribution modelling. Location: Europe, western Middle East and North Africa (but mainly the Mediterranean and Atlantic floristic regions). Methods: We used multi-locus DNA sequencing of archived specimens and phylogenetic and network analyses to reveal potential genetic lineages within S. omphalarioides. We used georeferenced specimens and bioclimatic variables to model the distributions of the species and two genetic lineages, and to find the main environmental correlates of the distributions. Results: Our phylogeographical results show that S. omphalarioides contains genetic variation that correlates with geographical distance, although with a few shared haplotypes across disjunct ranges. Distributions of the species as well as the two genetic lineages are non-random. Distribution models predict occurrences of the species as well as one of its genetic lineages outside the current range of the species. Main conclusions: Our results indicate that neither the species nor its component genetic lineages have reached their potential distributions. Shared haplotypes across disjunct distributions, and absence from regions with suitable refugial habitats along the Atlantic coast of Western Europe, support long- distance dispersal, rather than vicariance, as the primary cause for the current distribution of the species.
Keywords: archived biological collection, comparative dna-sequence analysis, conserva-, distribution modelling, genetic lineages, long-distance dispersal, old, tion
Colombo M, Damerau M, Hanel R, Salzburger W, Matschiner M (2014)
Journal of evolutionary biology.
According to theory, adaptive radiation is triggered by ecological opportunity that can arise through the colonization of new habitats, the extinction of antagonists, or the origin of key innovations. In the course of an adaptive radiation, diversification and morphological evolution are expected to slow down after an initial phase of rapid adaptation to vacant ecological niches, followed by speciation. Such 'early bursts' of diversification are thought to occur because niche space becomes increasingly filled over time. The diversification of Antarctic notothenioid fishes into over 120 species has become one of the prime examples of adaptive radiation in the marine realm, and has likely been triggered by an evolutionary key innovation in the form of the emergence of antifreeze glycoproteins. Here, we test, using a novel time-calibrated phylogeny of 49 species and five traits that characterize notothenioid body size and shape as well as buoyancy adaptations and habitat preferences, whether the notothenioid adaptive radiation is compatible with an early burst scenario. Extensive Bayesian model comparison shows that phylogenetic age estimates are highly dependent on model choice, and that models with unlinked gene trees are generally better supported and result in younger age estimates. We find strong evidence for elevated diversification rates in Antarctic notothenioids compared to outgroups, yet no sign of rate heterogeneity in the course of the radiation, except that the notothenioid family Artedidraconidae appears to show secondarily elevated diversification rates. We further observe an early burst in trophic morphology, suggesting that the notothenioid radiation proceeds in stages similar to other prominent examples of adaptive radiation. This article is protected by copyright. All rights reserved.
Keywords: adaptive radiation, early burst, geometric morphometrics, incomplete lineage, sorting, species tree
Ekrem T, KEvan P, Woodcock T, Herbert P (2014)
The Canadian Field Naturalist 128 77-79.
A specimen of the Black Witch (Ascalapha odorata) was collected in August 2006 near Churchill, Manitoba, at 58.7652°N. This represents the most northerly record for this species. DNA barcode comparison of 93 specimens of A. odorata in the Barcode of Life Data Systems revealed low genetic divergence even though these specimens were collected from a large geographical area. The haplotype of the Churchill specimen was shared by only one other individual (collected in the Yucatán Peninsula of Mexico) in the Barcode of Life Data Systems. A definite assignment of the geographic origin of the Churchill specimen is not possible with current data, but more extensive analysis of Central American populations with additional genetic markers might resolve this uncertainty.
Keywords: 2008, 2014, a, america, ascalapha odorata, be limited to central, black witch, distribution, dna barcoding, figure 1, genetic divergence, manitoba, mariposa de la muerte, migration, migratory, odorata is thought to, of, the natural breeding range
Elmendorf S, Henry G, Hollister R, Fosaa A, Gould W, Hermanutz L et al. (2014)
Experiment, monitoring, and gradient methods used to infer climate change effects on plant communities yield consistent patterns
Proceedings of the National Academy of Sciences 112(2) 201410088.
SignificanceMethodological constraints can limit our ability to quantify potential impacts of climate warming. We assessed the consistency of three approaches in estimating warming effects on plant community composition: manipulative warming experiments, repeat sampling under ambient temperature change (monitoring), and space-for-time substitution. The three approaches showed agreement in the direction of change (an increase in the relative abundance of species with a warmer thermal niche), but differed in the magnitude of change estimated. Experimental and monitoring approaches were similar in magnitude, whereas space-for-time comparisons indicated a much stronger response. These results suggest that all three approaches are valid, but experimental warming and long-term monitoring are best suited for forecasting impacts over the coming decades. Inference about future climate change impacts typically relies on one of three approaches: manipulative experiments, historical comparisons (broadly defined to include monitoring the response to ambient climate fluctuations using repeat sampling of plots, dendroecology, and paleoecology techniques), and space-for-time substitutions derived from sampling along environmental gradients. Potential limitations of all three approaches are recognized. Here we address the congruence among these three main approaches by comparing the degree to which tundra plant community composition changes (i) in response to in situ experimental warming, (ii) with interannual variability in summer temperature within sites, and (iii) over spatial gradients in summer temperature. We analyzed changes in plant community composition from repeat sampling (85 plant communities in 28 regions) and experimental warming studies (28 experiments in 14 regions) throughout arctic and alpine North America and Europe. Increases in the relative abundance of species with a warmer thermal niche were observed in response to warmer summer temperatures using all three methods; however, effect sizes were greater over broad-scale spatial gradients relative to either temporal variability in summer temperature within a site or summer temperature increases induced by experimental warming. The effect sizes for change over time within a site and with experimental warming were nearly identical. These results support the view that inferences based on space-for-time substitution overestimate the magnitude of responses to contemporary climate warming, because spatial gradients reflect long-term processes. In contrast, in situ experimental warming and monitoring approaches yield consistent estimates of the magnitude of response of plant communities to climate warming.
Keywords: climate change, space-for-time substitution, thermophilization, tundra, warming experiment
García-Gómez H, Garrido J, Vivanco M, Lassaletta L, Rábago I, Avila A et al. (2014)
Nitrogen deposition in Spain: Modeled patterns and threatened habitats within the Natura 2000 network
Science of the Total Environment 485-486C 450-460.
The Mediterranean Basin presents an extraordinary biological richness but very little information is available on the threat that air pollution, and in particular reactive nitrogen (N), can pose to biodiversity and ecosystem functioning. This study represents the first approach to assess the risk of N enrichment effects on Spanish ecosystems. The suitability of EMEP and CHIMERE air quality model systems as tools to identify those areas where effects of atmospheric N deposition could be occurring was tested. For this analysis, wet deposition of NO3(-) and NH4(+) estimated with EMEP and CHIMERE model systems were compared with measured data for the period 2005-2008 obtained from different monitoring networks in Spain. Wet N deposition was acceptably predicted by both models, showing better results for oxidized than for reduced nitrogen, particularly when using CHIMERE. Both models estimated higher wet deposition values in northern and northeastern Spain, and decreasing along a NE-SW axis. Total (wet+dry) nitrogen deposition in 2008 reached maxima values of 19.4 and 23.0kgNha(-1)year(-1) using EMEP and CHIMERE models respectively. Total N deposition was used to estimate the exceedance of N empirical critical loads in the Natura 2000 network. Grassland habitats proved to be the most threatened group, particularly in the northern alpine area, pointing out that biodiversity conservation in these protected areas could be endangered by N deposition. Other valuable mountain ecosystems can be also threatened, indicating the need to extend atmospheric deposition monitoring networks to higher altitudes in Spain.
Keywords: Air quality model, Alpine grasslands, Critical load exceedance, Monitoring network, Natura 2000 network, Nitrogen deposition
Halvorsen R, Mazzoni S, Bryn A, Bakkestuen V (2014)
Opportunities for improved distribution modelling practice via a strict maximum likelihood interpretation of MaxEnt
Maximum entropy (MaxEnt) modelling, as implemented in the Maxent software, has rapidly become one of the most popular methods for distribution modelling. Originally, MaxEnt was described as a machine-learning method. More recently, it has been explained from principles of Bayesian estimation. MaxEnt offers numerous options (variants of the method) and settings (tuning of parameters) to the users. A widespread practice of accepting the Maxent software’s default options and settings has been established, most likely because of ecologists’ lack of familiarity with machine-learning and Bayesian statistical concepts and the ease by which the default models are obtained in Maxent. However, these defaults have been shown, in many cases, to be suboptimal and exploration of alternatives has repeatedly been called for. In this paper, we derive MaxEnt from strict maximum likelihood principles, and point out parallels between MaxEnt and standard modelling tools like generalised linear models (GLM). Furthermore, we describe several new options opened by this new derivation of MaxEnt, which may improve MaxEnt practice. The most important of these is the option for selecting variables by subset selection methods instead of the ℓ1-regularisation method, which currently is the Maxent software default. Other new options include: incorporation of new transformations of explanatory variables and user control of the transformation process; improved variable contribution measures and options for variation partitioning; and improved output prediction formats. The new options are exemplified for a data set for the plant species Scorzonera humilis in SE Norway, which was analysed by the standard MaxEnt procedure in a previously published paper. We recommend that thorough comparisons between the proposed alternative options and default procedures and variants thereof be carried out. Distribution
Keywords: Air quality model, Alpine grasslands, Critical load exceedance, Monitoring network, Natura 2000 network, Nitrogen deposition