Influence of seasonality on cetacean diversity,abundance, distribution and habitat use in the western Mediterranean Sea: Implications for conservation          下载免费PDF全文

Antonella Arcangeli  Ilaria Campana  Marco A. Bologna 《水产资源保护:海洋与淡水生态系统》2017,27(5):995-1010

Ecological niche partitioning between Anopheles gambiae molecular forms in Cameroon: the ecological side of speciation     

Frédéric Simard  Diego Ayala  Guy Colince Kamdem  Marco Pombi  Joachim Etouna  Kenji Ose  Jean-Marie Fotsing  Didier Fontenille  Nora J Besansky  Carlo Costantini 《BMC ecology》2009,9(1):17-24

Background  

Speciation among members of the Anopheles gambiae complex is thought to be promoted by disruptive selection and ecological divergence acting on sets of adaptation genes protected from recombination by polymorphic paracentric chromosomal inversions. However, shared chromosomal polymorphisms between the M and S molecular forms of An. gambiae and insufficient information about their relationship with ecological divergence challenge this view. We used Geographic Information Systems, Ecological Niche Factor Analysis, and Bayesian multilocus genetic clustering to explore the nature and extent of ecological and chromosomal differentiation of M and S across all the biogeographic domains of Cameroon in Central Africa, in order to understand the role of chromosomal arrangements in ecological specialisation within and among molecular forms.  相似文献   

Living at the edge: biogeographic patterns of habitat segregation conform to speciation by niche expansion in Anopheles gambiae     

Carlo Costantini  Diego Ayala  Wamdaogo M Guelbeogo  Marco Pombi  Corentin Y Some  Imael HN Bassole  Kenji Ose  Jean-Marie Fotsing  N'Falé Sagnon  Didier Fontenille  Nora J Besansky  Frédéric Simard 《BMC ecology》2009,9(1):1-27

Background

Ongoing lineage splitting within the African malaria mosquito Anopheles gambiae is compatible with ecological speciation, the evolution of reproductive isolation by divergent natural selection acting on two populations exploiting alternative resources. Divergence between two molecular forms (M and S) identified by fixed differences in rDNA, and characterized by marked, although incomplete, reproductive isolation is occurring in West and Central Africa. To elucidate the role that ecology and geography play in speciation, we carried out a countrywide analysis of An. gambiae M and S habitat requirements, and that of their chromosomal variants, across Burkina Faso.

Results

Maps of relative abundance by geostatistical interpolators produced a distinct pattern of distribution: the M-form dominated in the northernmost arid zones, the S-form in the more humid southern regions. Maps of habitat suitability, quantified by Ecological Niche Factor Analysis based on 15 eco-geographical variables revealed less contrast among forms. M was peculiar as it occurred proportionally more in habitat of marginal quality. Measures of ecological niche breadth and overlap confirmed the mismatch between the fundamental and realized patterns of habitat occupation: forms segregated more than expected from the extent of divergence of their environmental envelope – a signature of niche expansion. Classification of chromosomal arm 2R karyotypes by multilocus genetic clustering identified two clusters loosely corresponding to molecular forms, with 'mismatches' representing admixed individuals due to shared ancestral polymorphism and/or residual hybridization. In multivariate ordination space, these karyotypes plotted in habitat of more marginal quality compared to non-admixed, 'typical', karyotypes. The distribution of 'typical' karyotypes along the main eco-climatic gradient followed a consistent pattern within and between forms, indicating an adaptive role of inversions at this geographical scale.

Conclusion

Ecological segregation between M and S is consistent with niche expansion into marginal habitats by chromosomal inversion variants during early lineage divergence; presumably, this process is promoted by inter-karyotype competition in the higher-quality core habitat. We propose that the appearance of favourable allelic combinations in other regions of suppressed recombination (e.g. pericentromeric portions defining speciation islands in An. gambiae) fosters development of reproductive isolation to protect linkage between separate chromosomal regions.  相似文献   

Forest structure and woody plant species composition along a fire chronosequence in mixed pine–oak forest in the Sierra Madre Oriental, Northeast Mexico     

Marco Aurelio Gonzlez-Tagle  Luitgard Schwendenmann  Javier Jimnez Prez  Rainer Schulz 《Forest Ecology and Management》2008,256(1-2):161-167

Although wildfires are occurring frequently in the pine–oak forests in the Sierra Madre Oriental (northeastern Mexico), data on post-fire succession and forest structure are still rare. Our objectives were to (1) assess the changes in woody plant species composition after fire and to (2) to relate successional patterns to environmental variability. Based on their fire history 23 plots were selected in the Parque Ecológico Chipinque (PECH). Changes in forest structure across the chronosequence of burned stands were deduced from density, height and diameter measurements of trees and shrubs (>5 cm in diameter) in all plots of 1000 m². Differences in woody plant species composition among the plots were evaluated using Shannon evenness measure and the Whittaker's measure and by Hierarchical cluster analysis and Detrended Correspondence Analysis. Hierarchical cluster analysis showed a high similarity among all recently burned plots, independed of the aspect. Multivariate analysis showed that local environmental factors, including time since fire, continue to structure species composition. Oak species (mainly Quercus rysophylla) resprouted successfully after fire and dominated young post-fire stands. Pine species (Pinus pseudotrobus and Pinus teocote) only appeared 18 years after fire and were the dominating species in mature stands (62 years after fire). In contrast, woody plant species composition in older stands tended also to be influenced by factors such as aspect and by the potential solar radiation (PSR) during the growing season. The results demonstrate that in the PECH, natural regeneration is sufficient and woody plant species composition will be similar to pre-fire conditions after 60 years of succession. We conclude that the park managers should consider incorporating natural disturbance regimes into their management practices.  相似文献   

Automatic recognition and measurement of single trees based on data from airborne laser scanning over the richly structured natural forests of the Bavarian Forest National Park     

Marco Heurich 《Forest Ecology and Management》2008

The purpose of this study was to test a method for delineating individual tree crowns based on a fully automated recognition methodology. The study material included small-footprint time-of-flight laser scanner data acquired in the spring and summer of 2002. The data were collected with a Toposys II airborne laser system flown over the Norway spruce (Picea abies) and European beech (Fagus sylvatica) dominated forests of the Bavarian Forest National Park, Germany. The applied algorithm, which earlier had been validated for Swedish forest conditions, is a watershed algorithm that is based on the use of laser scanning data. 2584 trees in a total of 28 representative reference stands, each 0.1–0.25 ha in area, were included in the investigation. With the algorithm, 76.9% of the trees in the upper layer could be recognised. This corresponds to 85.2% of the timber volume determined by ground measurements. The results for conifers were more accurate in this respect than for deciduous trees. A negative aspect was the number of falsely identified trees, the percentage of which was 5.4%.  相似文献   

Comparison of different culture media on the mycelial growth, sporangia and oospore production ofPhytophthora infestans     

Marco V. Medina  H. W. Platt 《American Journal of Potato Research》1999,76(3):121-125

The purpose of this study was to evaluate various culture media, with or without β-sitosterol, on mycelial growth, sporangia and oospore production by isolates ofPhytophthora infestans. Nine media were compared to rye agar (RA) which is frequently used to cultureP. infestans. Poor fungal growth across most isolates was observed on soybean agar, carrot agar and carrot agar with sterols relative to RA. Only clarified V8 juice containing β-sitosterol (CLV8S) resulted in significantly more sporangia production compared to RA. All other media performed similar to the RA. No significant differences were found in the sizes (length and width) of sporangia produced among the isolates tested on various media. Oospore production was greatest whenP. infestans was cultured on carrot agar with β-sitosterol (CAS) or CLV8S when compared to RA. Responses of isolate matings varied somewhat with an A2 isolate from Nova Scotia consistently producing fewer oospores in matings with A1 isolates compared to the other A1/A2 mating combinations. Rye agar and oat meal agar with or without β-sitosterol as well as clarified V8 juice agar with β-sitosterol are useful forin vitro growth of mycelium.  相似文献   

Application of Solid Phase Micro‐Extraction (SPME) to the analysis of pesticide residues in vegetables     

Marco Volante  Mirella Pontello  Laura Valoti  Manuela Cattaneo  Mascia Bianchi  Luisa Colzani 《Pest management science》2000,56(7):618-636

Solid Phase Micro‐Extraction (SPME) is a new analytical technique, based on capturing the analytes by adsorption onto an organic phase coating a glass fibre, and subsequent direct desorption into the injector of a gas chromatograph. This technique has been successfully applied in the analysis of organic contaminants in water, giving linear responses and, in some cases, high sensitivities. The present paper reports data about the application of SPME to the analysis of pesticide residues in a vegetable matrix, testing over nearly one hundred active compounds, with two types of adsorbent phase (polydimethylsiloxane and Carbowax/divinylbenzene). A vegetable matrix spiked with pesticides was analyzed by SPME and by a traditional multi‐residue method; recoveries were determined and compared for the two cases. The behaviour of the analytical response by SPME was studied in the range 0.01–1 mg kg⁻¹ by adding increasing amounts of given pesticide mixtures to the vegetable matrix. The procedure was further tested by analyzing real samples, and gave some difficulties in recovering the whole amount of some of the residues present (in comparison with the traditional method). The SPME method was then improved by pre‐extracting with acetone and sonicating before the extraction/adsorption step. The results obtained were satisfactory (some certified matrices were also tested) with good accordance between the two methods. Nevertheless some active compounds showed very low responses or remained undetectable by SPME in our experimental conditions. © 2000 Society of Chemical Industry  相似文献   

Assessing the influence of air speed and liquid flow rate on the droplet size and homogeneity in pneumatic spraying     

Paolo Balsari  Marco Grella  Paolo Marucco  Fabio Matta  Antonio Miranda‐Fuentes 《Pest management science》2019,75(2):366-379

  相似文献   

Impact of fungal and plant metabolites application on early development stages of pea powdery mildew     

Eleonora Barilli  María J Gonzlez‐Bernal  Alessio Cimmino  Francisco J Agudo‐Jurado  Marco Masi  Diego Rubiales  Antonio Evidente 《Pest management science》2019,75(9):2464-2473

  相似文献   

Integrated approach of multiple environmental datasets for the assessment of sediment contamination in marine areas affected by long-lasting industrial activity: the case study of Bagnoli (southern Italy)     

Sprovieri  Mario  Passaro  Salvatore  Ausili  Antonella  Bergamin  Luisa  Finoia  Maria Grazia  Gherardi  Serena  Molisso  Flavia  Quinci  Enza Maria  Sacchi  Marco  Sesta  Giulio  Trincardi  Fabio  Romano  Elena 《Journal of Soils and Sediments》2020,20(3):1692-1705

Purpose

The Bagnoli’s brownfield site (southern Italy) is an environmental priority for the Italian Government and is currently considered as a case study for the definition and application of innovative approaches to ecosystem recovery after a prolonged pollution history and eventual steel plant decommissioning.

Materials and methods

Here, we analyse high-quality datasets that constrain the distribution patterns and sources of contaminants in the coastal zone facing the site where the steel plant operated for almost one century. Innovative statistical approaches provide new insights into the temporal and spatial distribution of anthropogenic impacts, documented over the last 30 years, following lines of evidence emerging from investigations on grain size, TOC, heavy metals, PAHs, PCBs and high-resolution morpho-bathymetric information.

Results and discussion

The results derived from statistical analysis, referred also to the seafloor morphological variability, highlighted the presence of recent disposal of highly contaminated sediments and their potential pathways of dispersion to wider and deeper water zones.

Conclusions

The adopted multidisciplinary approach yields fundamental information towards an effective and proper ecosystem recovery of highly contaminated marine coastal areas and provides at the same time, a sound base for the refitting of decommissioned industrial plants.

  相似文献