Estimating how inflated or obscured effects of climate affect forecasted species distribution

Climate is one of the main drivers of species distribution. However, as different environmental factors tend to co-vary, the effect of climate cannot be taken at face value, as it may be either inflated or obscured by other correlated factors. We used the favourability models of four species (Alytes dickhilleni, Vipera latasti, Aquila fasciata and Capra pyrenaica) inhabiting Spanish mountains as case studies to evaluate the relative contribution of climate in their forecasted favourability by using variation partitioning and weighting the effect of climate in relation to non-climatic factors. By calculating the pure effect of the climatic factor, the pure effects of non-climatic factors, the shared climatic effect and the proportion of the pure effect of the climatic factor in relation to its apparent effect (r), we assessed the apparent effect and the pure independent effect of climate. We then projected both types of effects when modelling the future favourability for each species and combination of AOGCM-SRES (two Atmosphere-Ocean General Circulation Models: CGCM2 and ECHAM4, and two Special Reports on Emission Scenarios (SRES): A2 and B2). The results show that the apparent effect of climate can be either inflated (overrated) or obscured (underrated) by other correlated factors. These differences were species-specific; the sum of favourable areas forecasted according to the pure climatic effect differed from that forecasted according to the apparent climatic effect by about 61% on average for one of the species analyzed, and by about 20% on average for each of the other species. The pure effect of future climate on species distributions can only be estimated by combining climate with other factors. Transferring the pure climatic effect and the apparent climatic effect to the future delimits the maximum and minimum favourable areas forecasted for each species in each climate change scenario.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS). D. Romero is a PhD student at the University of Malaga with a grant of the Ministerio de Educacio´n y Ciencia (AP 2007-03633

Genes left behind: Climate change threatens cryptic genetic diversity in the canopy-forming seaweed bifurcaria bifurcata

The global redistribution of biodiversity will intensify in the coming decades of climate change, making projections of species range shifts and of associated genetic losses important components of conservation planning. Highly-structured marine species, notably brown seaweeds, often harbor unique genetic variation at warmer low-latitude rear edges and thus are of particular concern. Here, a combination of Ecological Niche Models (ENMs) and molecular data is used to forecast the potential near-future impacts of climate change for a warm-temperate, canopy forming seaweed, Bifurcaria bifurcata. ENMs for B. bifurcata were developed using marine and terrestrial climatic variables, and its range projected for 2040-50 and 2090-2100 under two greenhouse emission scenarios. Geographical patterns of genetic diversity were assessed by screening 18 populations spawning the entire distribution for two organelle genes and 6 microsatellite markers. The southern limit of B. bifurcata was predicted to shift northwards to central Morocco by the mid-century. By 2090-2100, depending on the emission scenario, it could either retreat further north to western Iberia or be relocated back to Western Sahara. At the opposing margin, B. bifurcata was predicted to expand its range to Scotland or even Norway. Microsatellite diversity and endemism were highest in Morocco, where a unique and very restricted lineage was also identified. Our results imply that B. bifurcata will maintain a relatively broad latitudinal distribution. Although its persistence is not threatened, the predicted extirpation of a unique southern lineage or even the entire Moroccan diversity hotspot will erase a rich evolutionary legacy and shrink global diversity to current (low) European levels. NW Africa and similarly understudied southern regions should receive added attention if expected range changes and diversity loss of warm-temperate species is not to occur unnoticed.Portuguese FCT (Fundacao para a Ciencia e a Tecnologia) [PTDC/AAC-CLI/109108/2008, EXPL/BIA-BIC/1471/2012, EXCL/AAG-GLO/0661/2012]; [SFRH/BPD/88935/2012]info:eu-repo/semantics/publishedVersio

Contrasting and congruent patterns of genetic structuring in two Microtus vole species using museum specimens

The common vole (Microtus arvalis) and the field vole (Microtus agrestis) are morphologically similar species but are ecological distinctive and differ in the details of their evolutionary history as revealed by mitochondrial DNA (mtDNA). The aim of this study is to describe patterns of genetic variability using microsatellite markers in populations of the common and field vole in Poland using museum specimens, to assess the degree of congruence with mtDNA variation and thereby determine the factors that influence current patterns of gene flow. We genotyped 190 individuals of the common vole at 11 loci and 190 individuals of the field vole at 13 loci. Overall differentiation based on F ST was higher for the common vole than in the field vole. We detected a significant isolation by distance pattern for both species. Bayesian analysis in STRUCTURE identified Eastern and Western geographic groups in Poland based on microsatellites for both species. The location of river barriers is likely to be the main factor in these partitions. The eastern-western subdivision with microsatellites does not coincide with the distribution of mtDNA lineages for either species. Unlike previous studies in the common and field vole elsewhere in Europe, we found no evidence of reproductive isolation between the mtDNA lineages of these species at their contact zones in Poland. This study highlights the different roles of evolutionary history and landscape in shaping contemporary genetic structure in voles in Poland

Persistence of butterfly populations in fragmented habitats along urban density gradients: motility helps

In a simulation study of genotypes conducted over 100 generations for more than 1600 butterfly’s individuals, we evaluate how the increase of anthropogenic fragmentation and reduction of habitat size along urbanisation gradients (from 7% to 59% of impervious land cover) influences genetic diversity and population persistence in butterfly species. We show that in areas characterised by a high urbanisation rate (> 56% impervious land cover), a large decrease of both genetic diversity (loss of 60-80% of initial observed heterozygosity) and population size (loss of 70-90% of individuals) is observed over time. This is confirmed by empirical data available for the mobile butterfly species Pieris rapae in a sub-part of the study area. Comparing simulated data for P. rapae with its normal dispersal ability and with a reduced dispersal ability, we also show that a higher dispersal ability can be an advantage to survive in an urban or highly fragmented environment. The results obtained here suggest that it is of high importance to account for population persistence, and confirm that it is crucial to maintain habitat size and connectivity in the context of land-use planning

A description of the sedimentology and palaeontology of the Late Triassic–Early Jurassic Elliot Formation in Lesotho

Sedimentological studies of the Late Triassic to Early Jurassic Elliot Formation (Karoo Supergroup) in Lesotho have proved to be a fundamental element in our research into the development of the main Karoo Basin of southern Africa. Complementing previous research in SouthAfrica, studies of the architecture of the sedimentary units in the Elliot Formation reveal that there are two contrasting types of sandstone body geometries, each resulting from different fluvial depositional styles. In the lower part of the formation, the sandstones resemble multi-storey channel-fills, interpreted as deposits of perennial, moderately meandering fluvial systems. On the other hand, the upper part of the formation is characterized by mostly tabular, multi-storey sheet sandstones which resulted from ephemeral fluvial processes. Based mainly on changes in the fluvial style and palaeocurrent pattern within the formation, the regional lithostratigraphic subdivision applied to the Elliot Formation in South Africa is applicable in Lesotho as well. This study adds detail and therefore refines the stratigraphic subdivision documented for the South African succession, and as such forms an important framework for palaeontological, palaeoecological and biostratigraphic studies in Lesotho.Palaeo-anthropology Scientific Trust National Research Foundatio

Cloning and characterization of 29 tetranucleotide and two dinucleotide polymorphic microsatellite loci from the endangered marbled murrelet (Brachyramphus marmoratus)

We developed 31 novel, polymorphic microsatellite loci in the marbled murrelet (Brachyramphus marmoratus), a critically endangered seabird. Variability was tested on 15 individuals from the Santa Cruz, California population, with each locus characterized by two to 12 alleles. Observed levels of heterozygosity ranged from 0.13 to 0.93. These loci provide a valuable means of assessing the population structure and demographic parameters of this species, which may be critical to its conservation across a fragmented habitat