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Mairal M, Sanmartín I, Pellissier L (2017)
Journal of Biogeography.
Aim The disjunct distribution patterns of sister taxa can arise when previously continuous distribution ranges are fragmented by environmental changes such as major climatic events. Populations become isolated on either side of the newly established environmental barrier, and absence of gene flow promotes allopatric speciation, in a process that is known as ecological vicariance. If climate change altered the ancestral range gradually, such as along temporal temperature or moisture gradients, the age of divergence of disjunct species should be related to the lineage tolerance to climatic conditions. Here, we investigate this hypothesis using as a study model the African Rand Flora, a continental-scale floristic pattern that relates sister taxa distributed on either side of the Saharan Desert. Location Africa, Macaronesia, Mediterranean Basin and the Middle East. Methods We estimated the extant climatic tolerances of 14 Rand Flora lineages based on present occurrence data, and correlated the phylogenetic age of divergence between vicariant clades. We tested whether the tempo of the vicariance in the Rand Flora lineages was associated with the average values of their climatic niches in agreement with niche-driven divergence. We hindcasted species ranges using species distribution models combined with palaeoclimate simulations to infer the potential distribution of each lineage's ancestors. Results We found a positive relationship between the lineage temperature niche and the age of the Rand Flora disjunction: lineages with subtropical affinities diverged first, whereas those with a higher tolerance to drier conditions (temperate or sub-xeric adaptations) exhibited younger disjunctions. The range reconstructions showed the existence of climatic corridors south of the Sahara in the wetter Late Miocene, which became interrupted during the mid-Pliocene warming event. Main conclusions Our results suggest that climate change leading to the formation of the Sahara Desert drove Rand Flora lineages divergences along a temporal sequence that matched the climatic niche of species.
Keywords: Rand Flora, continental disjunctions, extinction, niche conservatism, refuges, vicariance
Pertierra L, Aragón P, Shaw J, Bergstrom D, Terauds A, Olalla-Tárraga M (2017)
Global Change Biology.
The two non-native grasses that have established long-term populations in Antarctica (Poa pratensis and Poa annua) were studied from a global multidimensional thermal niche perspective to address the biological invasion risk to Antarctica. These two species exhibit contrasting introduction histories and reproductive strategies and represent two referential case studies of biological invasion processes. We used a multistep process with a range of species distribution modelling techniques (ecological niche factor analysis, multidimensional envelopes, distance/entropy algorithms) together with a suite of thermoclimatic variables, to characterize the potential ranges of these species. Their native bioclimatic thermal envelopes in Eurasia, together with the different naturalized populations across continents, were compared next. The potential niche of P. pratensis was wider at the cold extremes; however, P. annua life history attributes enable it to be a more successful colonizer. We observe that particularly cold summers are a key aspect of the unique Antarctic environment. In consequence, ruderals such as P. annua can quickly expand under such harsh conditions, whereas the more stress-tolerant P. pratensis endures and persist through steady growth. Compiled data on human pressure at the Antarctic Peninsula allowed us to provide site-specific biosecurity risk indicators. We conclude that several areas across the region are vulnerable to invasions from these and other similar species. This can only be visualized in species distribution models (SDMs) when accounting for founder populations that reveal nonanalogous conditions. Results reinforce the need for strict management practices to minimize introductions. Furthermore, our novel set of temperature-based bioclimatic GIS layers for ice-free terrestrial Antarctica provide a mechanism for regional and global species distribution models to be built for other potentially invasive species.
Keywords: Poaceae, biosecurity protocols, non-native species management, nonanalogous climate, species distribution models
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
Bosch J, Iglesias I, Muñoz M, de la Torre A (2016)
A Cartographic Tool for Managing African Swine Fever in Eurasia: Mapping Wild Boar Distribution Based on the Quality of Available Habitats
Transboundary and Emerging Diseases.
The current African swine fever (ASF) epidemic in Eurasia represents a risk for the swine industry with devastating socio-economic and political consequences. Wild boar appears to be a key factor in maintaining the disease in endemic areas (mainly the Russian Federation) and spreading the disease across borders, including within the European Union. To help predict and interpret the dynamics of ASF infection, we developed a standardized distribution map based on global land cover vegetation (GLOBCOVER) that quantifies the quality of available habitats (QAH) for wild boar across Eurasia as an indirect index for quantifying numbers of wild boar. QAHs were estimated using a seven-level scale based on expert opinion and found to correlate closely with georeferenced presence of wild boar (n = 22 362): the highest wild boar densities (74.47%) were found in areas at the two highest QAH levels, while the lowest densities (5.66%) were found in areas at the lowest QAH levels. Mapping notifications from 2007 to 2016 onto the QAH map showed that in endemic areas, 60% of ASF notifications occurred in domestic pigs, mostly in agricultural landscapes (QAHs 1.75 and 1) containing low-biosecurity domestic pig farms. In the EU, in contrast, 95% of ASF notifications occurred in wild boar, within natural landscapes (QAH 2). These results suggest that the QAH map can be a useful epi-tool for defining risk scenarios and identifying potential travel corridors for ASF. This tool will help inform resource allocation decisions and improve prevention, control and surveillance of ASF and potentially of other diseases affecting swine and wild boar in Eurasia.
Keywords: African swine fever, habitat, land coverage, surveillance, wild boar distribution
Calderón L, Campagna L, Wilke T, Lormee H, Eraud C, Dunn J et al. (2016)
Genomic evidence of demographic fluctuations and lack of genetic structure across flyways in a long distance migrant, the European turtle dove
BMC Evolutionary Biology 16(1) 237.
Understanding how past climatic oscillations have affected organismic evolution will help predict the impact that current climate change has on living organisms. The European turtle dove, Streptopelia turtur, is a warm-temperature adapted species and a long distance migrant that uses multiple flyways to move between Europe and Africa. Despite being abundant, it is categorized as vulnerable because of a long-term demographic decline. We studied the demographic history and population genetic structure of the European turtle dove using genomic data and mitochondrial DNA sequences from individuals sampled across Europe, and performing paleoclimatic niche modelling simulations. Overall our data suggest that this species is panmictic across Europe, and is not genetically structured across flyways. We found the genetic signatures of demographic fluctuations, inferring an effective population size (Ne) expansion that occurred between the late Pleistocene and early Holocene, followed by a decrease in the Ne that started between the mid Holocene and the present. Our niche modelling analyses suggest that the variations in the Ne are coincident with recent changes in the availability of suitable habitat. We argue that the European turtle dove is prone to undergo demographic fluctuations, a trait that makes it sensitive to anthropogenic impacts, especially when its numbers are decreasing. Also, considering the lack of genetic structure, we suggest all populations across Europe are equally relevant for conservation.
Keywords: Climate change, Conservation, Demography, Genomics, Migratory birds, Paleoclimatic, Population genetic structure, niche modelling
Calleja J, Mingorance L, Lara F (2016)
Epiphytic Bryophyte Communities of Prunus lusitanica Iberian Forests: Biogeographic Islands Shaped by Regional Climates
Cryptogamie, Bryologie 37(1) 53-85.
Epiphytic communities of Iberian forests remain partly unknown and most studies have focused on the dominant oak forests. We provide a comprehensive analysis and interpretation of the epiphytic bryophyte communities of forests dominated by the Tertiary relict evergreen cherry Prunus lusitanica. This type of forest, scattered in the western and northern half of the Iberian Peninsula, harbours a noticeable richness of epiphytic bryophytes, including an outstanding number of liverwort species. Their floristic composition varies markedly across the Peninsula yet is driven by the main climate patterns prevailing in the area. Multivariate analyses (TWINSPAN, CCA) render two main groups of epiphytic communities with their respective indicator species. Both groups share a high proportion of non-Mediterranean species, a circumstance that is most remarkable in the forests that fall within the Mediterranean Region, which could be considered as ecological refuges or biogeographic islands.
Keywords: Bryoflora, Iberian Peninsula, biodiversity, biogeographic elements, distribution, epiphytes, liverworts, mosses, species richness
Cardador L, Carrete M, Gallardo B, Tella J (2016)
Combining trade data and niche modelling improves predictions of the origin and distribution of non-native European populations of a globally invasive species
Journal of Biogeography.
Aim Although propagule pressure and environmental constraints are among the most important factors determining invasion success, studies considering both factors simultaneously are scarce. Moreover, while recent evidence suggests that the environmental requirements of individuals from different geographical ranges may be different, the role of propagule origin in invasions has been largely overlooked. Our aim was to disentangle the relative role of niche requirements, propagule origin and propagule pressure on the distribution of an invasive bird species. Location Europe, Asia and Africa. Methods We used species distribution models, niche and deviance partitioning analyses to investigate the relative roles of propagule pressure (international trade), origin of individuals (Asian or African), and environmental constraints in determining the distribution of invasive ring-necked parakeets across 25 European countries. Results Differences between niches of native Asian and African parakeets were found, with the Asian niche matching the European niche more closely. In the invasive European range, distribution of parakeets was mainly explained by the pure effect of year of first importation (as a proxy of time since first introduction), the pure effect of geographical origin of propagules and the joint effect of environmental suitability and year of first importation, but not by overall propagule pressure. Only when taking into account the fraction of individuals whose native niche fitted better the European conditions – Asian parakeets – was the role of propagule pressure highlighted by models. Main conclusions While environmental-based predictions calibrated on native ranges can constitute a useful first-screening tool, incorporating information about propagule pressure and especially about the variability in its geographical origin may result in a much more thorough assessment of invasion risk. Trade data reveal as a valuable proxy of propagule origin and pressure that can be combined with niche modelling for predicting the fate of trade-mediated invasions in a variety of organisms.
Keywords: Psittacula krameri, geographical origin, habitat suitability, international trade, invasive risks, propagule pressure, ring-necked parakeet
Chandler M, See L, Copas K, Bonde A, López B, Danielsen F et al. (2016)
To meet collective obligations towards biodiversity conservation and monitoring, it is essential that the world's governments and non-governmental organisations as well as the research community tap all possible sources of data and information, including new, fast-growing sources such as citizen science (CS), in which volunteers participate in some or all aspects of environmental assessments. Through compilation of a database on CS and community-based monitoring (CBM, a subset of CS) programs, we assess where contributions from CS and CBM are significant and where opportunities for growth exist. We use the Essential Biodiversity Variable framework to describe the range of biodiversity data needed to track progress towards global biodiversity targets, and we assess strengths and gaps in geographical and taxonomic coverage. Our results show that existing CS and CBM data particularly provide large-scale data on species distribution and population abundance, species traits such as phenology, and ecosystem function variables such as primary and secondary productivity. Only birds, Lepidoptera and plants are monitored at scale. Most CS schemes are found in Europe, North America, South Africa, India, and Australia. We then explore what can be learned from successful CS/CBM programs that would facilitate the scaling up of current efforts, how existing strengths in data coverage can be better exploited, and the strategies that could maximise the synergies between CS/CBM and other approaches for monitoring biodiversity, in particular from remote sensing. More and better targeted funding will be needed, if CS/CBM programs are to contribute further to international biodiversity monitoring.
Keywords: Citizen science, Community-based monitoring, Databases, Essential biodiversity variables (EBV), Global Biodiversity Information Facility (GBIF), Group on Earth Observations Biodiversity Observati
Delgado-Baquerizo M, Reich P, García-Palacios P, Milla R (2016)
We lack both a theoretical framework and solid empirical data to understand domestication impacts on plant chemistry. We hypothesised that domestication increased leaf N and P to support high plant production rates, but biogeographic and climate patterns further influenced the magnitude and direction of changes in specific aspects of chemistry and stoichiometry. To test these hypotheses, we used a data set of leaf C, N and P from 21 herbaceous crops and their wild progenitors. Domestication increased leaf N and/or P for 57% of the crops. Moreover, the latitude of the domestication sites (negatively related to temperature) modulated the domestication effects on P (+), C (-), N : P (-) and C : P (-) ratios. Further results from a litter decomposition assay showed that domestication effects on litter chemistry affected the availability of soil N and P. Our findings draw attention to evolutionary effects of domestication legacies on plant and soil stoichiometry and related ecosystem services (e.g. plant yield and soil fertility).
Keywords: T-physiology hypothesis, decomposition, growth rate hypothesis, nutrient cycling, rops, soil age hypothesis
Duan R, Kong X, Huang M, Varela S, Ji X (2016)
The potential effects of climate change on amphibian distribution, range fragmentation and turnover in China
Many studies predict that climate change will cause species movement and turnover, but few studies have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5) and two time periods (the 2050s and 2070s). Our results show that climate change will cause a major shift in the spatial patterns of amphibian diversity. Suitable habitats for over 90% of species will be located in the north of the current range, for over 95% of species in higher altitudes, and for over 75% of species in the west of the current range. The distributions of species predicted to move westwards, southwards and to higher altitudes will contract, while the ranges of the species not showing these trends will expand. Amphibians will lose 20% of their original ranges on average; the distribution outside current ranges will increase by 15%. Climate change will likely modify the spatial configuration of climatically suitable areas. Changes in area and fragmentation of climatically suitable patches are related, which means that species may be simultaneously affected by different stressors as a consequence of climate change.
Keywords: Amphibians, Climate impacts, Dispersal, Distribution, Fragmentation, MaxEnt, Range shifts, Turnover