Genetic diversity in old populations of sessile oak from Calabria assessed by nuclear and chloroplast SSR     

Antonio LUPINI  Meriem Miyassa ACI  Antonio MAUCERI  Giuseppe LUZZI  Silvio BAGNATO  Giuliano MENGUZZATO  Francesco MERCATI  Francesco SUNSERI 《山地科学学报》2019,(5)

In the framework of forest resources conservation, this study aims to understand the dynamic and the genetic structure of sessile oak forests in Calabria, Italy. Two old populations of sessile oak(Quercus petraea(Mattuschka) Liebl.) from two areas of Sila and Aspromonte massifs in Calabria were analyzed for genetic diversity and population structure based on 6 nuclear simple sequence repeat(nSSR) and 4 chloroplastic SSR(cpSSR) loci. The populations displayed high amount of genetic diversity, which was toughly structured according to their geographical origins. Number of alleles at SSR loci ranged from 11 to 20 with an average of 13.5 per locus. Gene diversity(expected heterozygosity, He) estimates ranged from 0.575 to 0.834 with a mean of 0.749. The observed heterozygosity(Ho) was on average 0.458 ranging from 0.150 to 0.682. Polymorphism information content(PIC) values ranged from 0.625 to 0.865 with an average of 0.787. The analysis of molecular variance(AMOVA) highlighted a significant higher estimated variance within populations compared to among populations. Finally, the analysis of haplotypes by using cpSSR suggested a higher diversification in the population from Sila. Hierarchical clustering analysis grouped the genotypes into two major clusters, which agreed with the geographic origin of populations, and was confirmed by the Discriminant Analysis of Principal Components(DAPC). The first cluster included plants/population from Sila massif, while the second encompassed mostly plants/population sampled in Aspromonte massif. Finally, model-based clustering by STRUCTURE analysis also supported the presence of clear genetic structuring in the collection with two major populations(K=2) supported to PCoA analysis as well. Finally, our data indicated the Aspromonte population as a marginal forest with fragmented distribution suggesting different strategies of preservation than in Sila massif.  相似文献   

Sources and distribution of organic matter in northern Patagonia fjords,Chile (∼44–47°S): A multi-tracer approach for carbon cycling assessment     

Julio Sepúlveda  Silvio Pantoja  Konrad A. Hughen 《Continental Shelf Research》2011,31(3-4):315-329

We investigated the provenance of organic matter in the inner fjord area of northern Patagonia, Chile (～44–47°S), by studying the elemental (organic carbon, total nitrogen), isotopic (δ¹³C, δ¹⁵N), and biomarker (n-alkanoic acids from vascular plant waxes) composition of surface sediments as well as local marine and terrestrial organic matter. Average end-member values of N/C, δ¹³C, and δ¹⁵N from organic matter were 0.127±0.010, ?19.8±0.3‰, and 9.9±0.5‰ for autochthonous (marine) sources and 0.040±0.018, ?29.3±2.1‰, and 0.2±3.0‰ for allochthonous (terrestrial) sources. Using a mixing equation based on these two end-members, we calculated the relative contribution of marine and terrestrial organic carbon from the open ocean to the heads of fjords close to river outlets. The input of marine-derived organic carbon varied widely and accounted for 13–96% (average 61%) of the organic carbon pool of surface sediments. Integrated regional calculations for the inner fjord system of northern Patagonia covered in this study, which encompasses an area of ～4280 km², suggest that carbon accumulation may account for between 2.3 and 7.8×10⁴ ton C yr^?1. This represents a storage capacity of marine-derived carbon between 1.8 and 6.2×10⁴ ton yr^?1, which corresponds to an assimilation rate of CO₂ by marine photosynthesis between 0.06 and 0.23×10⁶ ton yr^?1. This rate suggests that the entire fjord system of Patagonia, which covers an area of ～240,000 km², may represent a potentially important region for the global burial of marine organic matter and the sequestration of atmospheric CO₂.  相似文献   

Benchmarking sustainability in cities: The role of indicators and future scenarios     

Christopher T. Boyko  Mark R. Gaterell  Austin R.G. Barber  Julie Brown  John R. Bryson  David Butler  Silvio Caputo  Maria Caserio  Richard Coles  Rachel Cooper  Gemma Davies  Raziyeh Farmani  James Hale  A. Chantal Hales  C. Nicholas Hewitt  Dexter V.L. Hunt  Lubo Jankovic  Ian Jefferson  Joanne M. Leach  D. Rachel Lombardi  Christopher D.F. Rogers 《Global Environmental Change》2012,22(1):245-254

Scenarios are a useful tool to help think about and visualise the future and, as such, are utilised by many policymakers and practitioners. Future scenarios have not been used to explore the urban context in much depth, yet have the potential to provide valuable insights into the robustness of decisions being made today in the name of sustainability. As part of a major research project entitled Urban Futures, a toolkit has been developed in the UK to facilitate the use of scenarios in any urban context and at any scale relevant to that context. The toolkit comprises two key components, namely, (i) a series of indicators comprising both generic and topic area-specific indicators (e.g., air quality, biodiversity, density, water) that measure sustainability performance and (ii) a list of characteristics (i.e., 1–2-sentence statements about a feature, issue or small set of issues) that describe four future scenarios. In combination, these two components enable us to measure the performance of any given sustainability indicator, and establish the relative sensitivity or vulnerability of that indicator to the different future scenarios. An important aspect of the methodology underpinning the toolkit is that it is flexible enough to incorporate new scenarios, characteristics and indicators, thereby allowing the long-term performance of our urban environments to be considered in the broadest possible sense.  相似文献   

Late Holocene marine productivity changes in Northern Patagonia-Chile inferred from a multi-proxy analysis of Jacaf channel sediments     

Lorena Rebolledo  Julio Sepúlveda  Carina B. Lange  Silvio Pantoja  Sébastien Bertrand  Konrad Hughen  Dante Figueroa 《Estuarine, Coastal and Shelf Science》2008

A multi-proxy approach based on organic (organic carbon, alkenones, and C/N) and inorganic geochemical proxies (biogenic opal, inorganic carbon, Fe, Ti, and Ca) preserved in the sediments of the Jacaf channel (CF7-PC33; 44°21′S, 72°58′W, 510 m water depth), Chilean fjords, yields evidence of major past productivity fluctuations in accordance with climatic changes over the last ∼1800 years. The downcore record clearly shows two productivity/climate modes. The first period, prior to 900 cal yr BP, is characterized by decreased marine productivity and a reduced continental signal, pointing to diminished precipitation and runoff. In contrast, the second period between ∼750 cal yr BP and the late 1800s (top of core) is illustrated by elevated productivity and an increased continental signal, suggesting higher precipitation and runoff. Both time intervals are separated by a relatively abrupt transition of ∼150 years which roughly coincides with the beginning of the Little Ice Age. The increased content of freshwater diatoms and Chrysophyte cysts that characterize the last 200 years of the latter mode coincides with a significant decrease in the carbonate content of the sediment; together they further indicate increased terrigenous contributions and decreased marine carbonate productivity at the end of the Little Ice Age. The correspondence between our record and other paleoclimate studies carried out in South America and Antarctica demonstrates that the Chilean fjord area of Northern Patagonia is not just sensitive to local climatic variability but also to regional and possibly global variability.  相似文献   

The role of pre-existing faults in the structural evolution of thrust systems: Insights from the Ligurian Alps (Italy)     

Lorenzo Bonini  Giorgio Dallagiovanna  Silvio Seno 《Tectonophysics》2010,480(1-4):73-87

New structural and stratigraphic data for a selected area of the Ligurian Alps are combined in order to assess and discuss the role played by extensional structures in the southernmost segment of the Western Alps during thrusting. Restored cross-sections and field data suggest that the structural style in the external sector of the chain may depend upon the presence of pre-orogenic normal faults ascribed to three extensional events linked to different geodynamic contexts: (i) Permian post-Variscan plate reorganisation, (ii) Mesozoic rifting–drifting phases leading to the opening of the Alpine Tethys, and (iii) Eocenic development of the European foreland basins. During positive inversion in Eocene times, a thin-skinned thrust system developed in this area, followed by a thick-skinned phase. In both situations the inherited extensional structures played fundamental roles: during the thin-skinned phase they conditioned the thrusting sequence, also producing large-scale buckle folds and partial reactivations; during the thick-skinned phase the strain was compartmentalized and partitioned by pre-existing faults.The kinematic model of the external sectors of the Ligurian chain also allows the re-assessment of the Alpine evolution of the front-foreland transition, including: (i) indirect confirmation that in the Eocene the Ligurian Briançonnais and Dauphinois domains were not separated by the Valais-Pyrenean oceanic basin; (ii) that the thin-skinned phase progressively changed into thick-skinned; (iii) the assertion that there were no significant deformations from the Oligocene to the present-day, and the Corsica–Sardinia block rotation only produced a change in orientation of previously formed structures and normal fault system development.  相似文献   

Simulations of the Madden–Julian oscillation in four pairs of coupled and uncoupled global models     

Chidong Zhang  Min Dong  Silvio Gualdi  Harry H. Hendon  Eric D. Maloney  Andrew Marshall  Kenneth R. Sperber  Wanqiu Wang 《Climate Dynamics》2006,27(6):573-592

The status of the numerical reproduction of the Madden–Julian Oscillation (MJO) by current global models was assessed through diagnoses of four pairs of coupled and uncoupled simulations. Slow eastward propagation of the MJO, especially in low-level zonal wind, is realistic in all these simulations. However, the simulated MJO suffers from several common problems. The MJO signal in precipitation is generally too weak and often eroded by an unrealistic split of an equatorial maximum of precipitation into a double ITCZ structure over the western Pacific. The MJO signal in low-level zonal wind, on the other hand, is sometimes too strong over the eastern Pacific but too weak over the Indian Ocean. The observed phase relationship between precipitation and low-level zonal wind associated with the MJO in the western Pacific and their coherence in general are not reproduced by the models. The seasonal migration in latitude of MJO activity is missing in most simulations. Air–sea coupling generally strengthens the simulated eastward propagating signal, but its effects on the phase relationship and coherence between precipitation and low-level zonal wind, and on their geographic distributions, seasonal cycles, and interannual variability are inconsistent among the simulations. Such inconsistency cautions generalization of results from MJO simulations using a single model. In comparison to observations, biases in the simulated MJO appear to be related to biases in the background state of mean precipitation, low-level zonal wind, and boundary-layer moisture convergence. This study concludes that, while the realistic simulations of the eastward propagation of the MJO are encouraging, reproducing other fundamental features of the MJO by current global models remains an unmet challenge.

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Chidong ZhangEmail:

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The effects of climate change on potential groundwater recharge in Great Britain     

M. Herrera‐Pantoja  K. M. Hiscock 《水文研究》2008,22(1):73-86

The predicted increase in mean global temperature due to climate change is expected to affect water availability and, in turn, cause both environmental and societal impacts. To understand the potential impact of climate change on future sustainable water resources, this paper outlines a methodology to quantify the effects of climate change on potential groundwater recharge (or hydrological excess water) for three locations in the north and south of Great Britain. Using results from a stochastic weather generator, actual evapotranspiration and potential groundwater recharge time‐series for the historic baseline 1961–1990 and for a future ‘high’ greenhouse gas emissions scenario for the 2020s, 2050s and 2080s time periods were simulated for Coltishall in East Anglia, Gatwick in southeast England and Paisley in west Scotland. Under the ‘high’ gas emissions scenario, results showed a decrease of 20% in potential groundwater recharge for Coltishall, 40% for Gatwick and 7% for Paisley by the end of this century. The persistence of dry periods is shown to increase for the three sites during the 2050s and 2080s. Gatwick presents the driest conditions, Coltishall the largest variability of wet and dry periods and Paisley little variability. For Paisley, the main effect of climate change is evident during the dry season (April–September), when the potential amount of hydrological excess water decreases by 88% during the 2080s. Overall, it is concluded that future climate may present a decrease in potential groundwater recharge that will increase stress on local and regional groundwater resources that are already under ecosystem and water supply pressures. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Methane in shallow cold seeps at Mocha Island off central Chile     

Gerdhard L. JessenSilvio Pantoja  Marcelo A. GutiérrezRenato A. Quiñones  Rodrigo R. GonzálezJavier Sellanes  Matthias Y. KellermannKai-Uwe Hinrichs 《Continental Shelf Research》2011,31(6):574-581

We studied for the first time the intertidal and subtidal gas seepage system in Mocha Island off Central Chile. Four main seepage sites were investigated (of which one site included about 150 bubbling points) that release from 150 to 240 tonnes CH₄ into the atmosphere per year. The total amount of methane emitted into the atmosphere is estimated in the order of 800 tonnes per year. The gases emanated from the seeps contain 70% methane, and the stable carbon isotopic composition of methane, δ¹³C-CH₄ averaged −44.4±1.4‰ which indicates a major contribution of thermogenic gas. Adjacent to one of the subtidal seeps, rocky substrates support a diverse community of microbial filaments, macroalgae, and benthic organisms. While stable carbon isotopic compositions of marine benthic organisms indicate a dominant photosynthesis-based food web, those of some hard-substrate invertebrates were in the range −48.8‰ to −36.8‰, suggesting assimilation of methane-derived carbon by some selected taxa. This work highlights the potential subsidy of the trophic web by CH₄-C, and that its emission to the atmosphere justifies the need of evaluating the use of methane to support the energy requirements of the local community.  相似文献   

VST OmegaCAM difference image analysis     

Fedor I. Getman  Silvio Leccia  Aniello Grado  Roberto Silvotti 《Experimental Astronomy》2013,35(1-2):319-327

We present a modified version of the difference image analysis software developed by the OGLE collaboration (DIAPL) and its implementation within AstroWISE environment. Python interface and parallel execution are described. Examples of graphical output on simulated data set are presented. The tool will be used in VST surveys for photometric variability search.  相似文献   

Teleconnection–extreme precipitation relationships over the Mediterranean region     

Simon O. Krichak  Joseph S. Breitgand  Silvio Gualdi  Steven B. Feldstein 《Theoretical and Applied Climatology》2014,117(3-4):679-692

The relationship between five teleconnection patterns (North Atlantic Oscillation (NAO), Arctic Oscillation (AO), East Atlantic/Western Russian (EAWR) pattern, Scandinavian (SCAND) pattern, and El Niño Southern Oscillation (ENSO)) and the frequency of occurrence of days (per month) with extreme precipitation in the Euro-Mediterranean region is investigated with National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis data. To quantify the teleconnection–precipitation relationships over the Euro-Mediterranean region, linear correlations are calculated between the monthly teleconnection indices for the five patterns and time series at each grid point of the monthly frequency of days with extreme precipitation, focusing on daily precipitation amounts that exceed a particular threshold value (a 90 % threshold is used). To evaluate dynamical processes, the teleconnection indices are also correlated with the frequencies of days with extreme values of dynamic tropopause pressure and precipitable water. The former quantity is used as a proxy for potential vorticity intrusions and the latter to identify regions of enhanced moisture. The results of this analysis indicates positive, statistically significant correlations between the NAO, AO, and SCAND indices and the frequency of extreme precipitation in the western Mediterranean; positive (negative) correlations between the EAWR index and the extreme precipitation frequency in the eastern (western) Mediterranean; and a positive correlation between the Niño3.4 index and the extreme precipitation frequency over the Iberian Peninsula and the Middle East. For all of the teleconnection patterns other than ENSO, the dynamic tropopause pressure correlation patterns resemble those for the precipitation. In contrast, similar precipitation and precipitable water correlation patterns are observed only for ENSO. These findings suggest that the teleconnections affect the interannual variation of the frequency of days with extreme precipitation over a large part of the Euro-Mediterranean region through their impact on the spatial distribution of regions with enhanced potential vorticity and air moisture.  相似文献