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1.
By means of columnar and thin-layer chromatography the presence of carotenoids in Ostrea edulis L. (Bivalvia: Ostreacea) from the Lagoon Venice (Italy), was studied.The following carotenoids were founds: -, -, -carotene, -carotene epoxide, lutein (free and epoxide from), zeaxanthin, diatoxanthin, mutatoxanthin and astaxanthin. The dominating carotenoids were lutein.The total contents varied within the range of 5.4–8.1 µg/g wet weight.  相似文献   

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Forested urban areas provide many important ecosystem services and their preservation is considered of paramount importance. Although urban forest are known to host a high diversity of saproxylic beetles (i.e. those associated with dead wood), contributions dealing with the role of urban green spaces for their conservation are lacking. We investigated the importance of urban green spaces for saproxylic and non-saproxylic tenebrionid beetles in urban Rome. Based on species vulnerability scores we calculated two indices of area prioritisation, the Biodiversity Conservation Concern (BCC) and the Biodiversity Conservation Weight (BCW) for saproxylic and non-saproxylic species. Site area and forest surface correlated positively with saproxylic richness, whereas site isolation correlated negatively with non-saproxylic richness. BCC and BCW values for saproxylic species were positively correlated with distance from the city centre. For non-saproxylic species, BCW values were negatively correlated with distance from adjacent areas. These results suggest that saproxylic beetles require large areas covered by forest, but are not strongly influenced by isolation, which is important for non-saproxylic species. Non-saproxylic tenebrionids have limited dispersal capabilities, which explains their sensitivity to isolation, but are generally eurytopic species frequently found even in the city centre. By contrast, most saproxylic species are able to fly, but are mainly found in peripheral areas with large and relatively well preserved forest fragments. Maintaining and possibly enhancing connectivity among green spaces is important for the conservation of non-saproxylic species, whereas preserving large forest surfaces, especially in peripheral areas, is needed for the conservation of saproxylic species.  相似文献   

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Summer bioclimatic discomfort is a significant public health problem. Bioclimatic characterisations of populations living in urban areas are usually very poor, although the risks are relatively higher in cities because of the phenomenon known as the “urban heat island”. We compared airport, rural, and urban bioclimatic conditions in terms of apparent temperature, Thom index, and temperature alone in several sites within a radius of approximately 25 km from the city of Bologna (Italy). The comparison between meteorological monitoring stations within and near the urban area showed the large impact of the urban heat island effect. Nighttime data showed the largest differences among the investigated sites. Minimum apparent temperatures at rural stations were about 3.5°C lower than the urban 30 m reference station, and 6°C lower than the 2 m urban site. The 2 m apparent temperature values within the urban area were several degrees higher (typically 2°C) than those taken above the roof, both for minimum and maximum values. Temporal trends in the different sites were highly correlated (generally above 0.90), but regression residuals were sometimes quite large. Finally, epidemiological implications are briefly addressed.  相似文献   

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Curiel  D.  Guidetti  P.  Bellemo  G.  Scattolin  M.  Marzocchi  M. 《Hydrobiologia》2002,477(1-3):209-219
Since its appearance in 1992 in the lagoon of Venice, the brown algae Undaria pinnatifida (kelp) has gradually expanded along the banks of canals both at Chioggia and Venice, becoming the dominant species in the local algal community chiefly from February to July. In Chioggia Island, where another brown seaweed (Sargassum muticum) is present since 1992, the spreading of Undaria reaches a plateau. In Venice Island, instead, the colonisation process is still in progress. During 1999, the kelp has colonised the main canals (e.g. The Grand Canal) and, subsequently, the small inner ones. In order to evaluate the dynamics of substrate re-colonisation by Undaria, two mechanical eradications were carried out during (March) and after the fertile period (July) of the algae. Such experimental manipulations provided evidence of the fast re-colonisation potential of the algae mainly attributable to its efficient reproductive system. Eradication made during the fertile period, in fact, permitted the kelp development during the following year, while re-colonisation has started 2 years later where eradication was performed after the reproductive period. A significant decrease in the surface covered by other species has been observed both in shallow (Ulva rigida, Enteromorpha spp., Antithamnion pectinatum, Chondracanthus acicularis) and deeper areas (Rhodymenia ardissonei) during the period of maximum development of U. pinnatifida. On the basis of the results of this study, the following conclusions can be drawn: (1) the alga U. pinnatifida is continuously expanding in lagoon environments of Venice; (2) in order to limit its spreading, mechanical eradications would be done on a large spatial scale and before the zoospores release; (3) there is suggestive evidence of competition between Undaria and the remaining indigenous algae.  相似文献   

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Long-term studies of the ground beetle fauna of Southeastern Altai (SEA) revealed 33 genera and 185 species; 3 and 15 species are reported for the first time from Russia and SEA, respectively. The following genera are the most diverse: Bembidion (47 species), Amara and Harpalus (21 each), Pterostichus (14), and Nebria (13). The subarid (35%) and boreal (32%) species prevail in the arealogical spectrum, while the mountain endemics comprise 13% of the fauna. The carabid fauna of SEA is heterogeneous in composition and differs significantly from that of the Western and Central Altai. The boreal mountain component mostly comprises tundra species with circum-boreal or circum-arctic ranges, while the subarid component (typical Mongolian together with Ancient Mediterranean species) forms more than one-half of the species diversity in the mountain basins. The species diversity increases from the nival mountain belt (15 species, predominantly Altai-Sayan endemics) to moss-lichen tundras (40, mostly boreal, species). The variety of habitats and constant hydrothermal regimes in the intrazonal valley communities determine high taxonomic diversity of Carabidae, including both tundra or meadow-steppe species typical of the region and some forest ones. Under the condition of moisture deficiency, many steppe species also concentrate in river floodplains.  相似文献   

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The Azores archipelago (Portugal) is formed by nine islands whose relative positions define them as three geographical groups: Eastern (S. Miguel and Sta. Maria), Central (Terceira, Faial, Pico, Graciosa and S. Jorge) and Western (Flores and Corvo). Using the father's surname of 187,398 individuals living on the nine Azorean Islands, a population analysis based on inter-island relationship and hierarchical organization was conducted. The relation between islands was investigated using summary statistics, analysis of molecular variance (AMOVA) as well as graphical methods. When the values of heteronymy were contrasted with values of gene diversity based on haplogroup frequencies of the Y chromosome, it was possible to verify that Graciosa and Sta. Maria appeared to have the least diverse populations, and that Flores, despite its smaller population size and geographical isolation, has considerably higher levels of diversity. As for inter-island relationships, the difficulty of directly interpreting summary statistics values was evidenced. The AMOVA revealed that only 0.77% of the variation in surnames can be attributed to among-island variation, a value that, although small, can be considered significant. Application of Malécot's model revealed that geographic distance has an important impact in the genetic structure of the archipelago. Monmonier's maximum-difference algorithm demonstrated that the most isolated island of the archipelago appears to be Graciosa, followed by the islands of the Western group and by Sta. Maria. After integrating values of summary statistics with results from AMOVA and graphical methods, a more accurate genetic profile of the Azores, highly supported by genetic data, has emerged.  相似文献   

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During 2002–2009, we surveyed butterflies at 73 bogs, 20 adjacent lowland roadsides, and 5 nearby upland roadsides in northern Wisconsin and three bogs in central Wisconsin, with additional observations from 1986 to 2001. Especially in northern Wisconsin, bogs are relatively unaffected by humans, but naturally comprise <1% of the landscape. Bog specialist species composition varied by bog type (muskeg, kettlehole, coastal peatland). Specialist abundance also varied significantly both among bog types and within type among sites. A number of bog specialists frequently occurred in numerous examples of bogs, including all three types. But virtually no specialist individuals occurred in nearby upland roadsides. Northern Wisconsin bogs had similar specialist species richness compared to large barrens and heaths in the same region. Specialist species comprised a small proportion (10%) of all butterfly species recorded in bogs, similar to proportions reported for specialists in tallgrass prairie and barrens. However, specialists accounted for nearly half the total individuals recorded in bogs, comparable to proportions of specialists found in less fragmented vegetation (barrens) and larger patches of favorably managed prairie, but far exceeding proportions observed in other highly fragmented prairie patches. A fundamental lesson may be that aiming to conserve typical ecosystems, even if native, and their average processes, leads to average (generalist) butterflies. Bogs have different vegetation types superimposed on each other, including bog, heath, forest, sedge meadow, and wet meadow associates in the same spots. Conservation management needs to avoid simplifying the vegetation to one layer, reducing specialist fauna. Long-term vegetative consistency, as in bogs, is advised for conservation management of specialist butterflies in other fragmented vegetations.  相似文献   

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We present the EU LIFE PonDerat project, which is aimed at restoring the natural ecosystems of the Pontine Archipelago, a group of islands located off the western coast of Italy. The spread of invasive species is a major environmental threat on these islands, which are rich in rare habitats and endemic species and are important sites for the conservation of Mediterranean biodiversity. The project focuses on the conservation of species and habitats that are protected by EU laws but are currently threatened by introduced plants and animals. The main targets of the control measures are black rats, feral goats, mouflons and invasive plants of the genus Carpobrotus. Conservation measures focus on the shearwaters Puffinus yelkouan and Calonectris diomedea, which are endemic to the Mediterranean and are listed in Annex I of the European Bird Directive. Conservation measures also focus on island habitats of great biogeographical value, which are listed in Annex I of the European Habitats Directive and are seriously threatened by introduced herbivores and by invasive plants. The main outcome expected from this project is that the restoration of ecosystem functions will enhance the breeding success and population size of shearwaters and lead to the recovery of target habitats.  相似文献   

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Interpreting data on distribution or population trends may be difficult unless detection probability is accounted for. We wished to determine the detectability of the rare and patchily distributed cobblestone tiger beetle (Cicindela marginipennis) along the upper Genesee River in western New York for development of a monitoring strategy. We used occupancy surveys and distance sampling to examine two types of detectability. The first type was site-level detectability: the probability of detecting a single cobblestone tiger beetle on an occupied cobble bar, calculated using program PRESENCE. The second type was individual-level detectability: the probability of detecting an individual cobblestone tiger beetle in a population on a single cobble bar, calculated using program DISTANCE. Our occupancy surveys consisted of collecting presence and absence data on cobble bars along the Genesee River; these showed a relatively narrow range of site-level detection probabilities (0.60?C0.68) for cobblestone tiger beetles in 2008 and 2009. Three visits were necessary to detect cobblestone tiger beetles on 90% of occupied cobble bars. Individual cobblestone tiger beetles were detectable one-half of the time (0.50) in our surveys. It is important for ecologists to distinguish between the two kinds of detectability, as monitoring implications could differ substantially depending on which is calculated. Our monitoring recommendations include (1) continuing occupancy surveys with at least three visits to each cobble bar; (2) conducting occupancy surveys between 10:00 and 17:00 on warm sunny days in mid-July and mid-August; and (3) conducting surveys at three- to five-year intervals depending on the study objective.  相似文献   

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Assessing the scale of ecological changes that have occurred since the onset of the Anthropocene is challenging. One major problem is that of shifting baselines, whereby the norms we set for judging the state of species, populations, or ecosystems change over time due to incomplete information. Here we show how data mining can be used to fill some of the information gaps fueling shifting baselines. We used as example an elusive species, the wolverine (Gulo gulo), given that information gaps are so prevailing for such species. We applied the concept of data mining to search documents hosted on publicly accessible online repositories and found information about the historical occurrence of wolverines that allowed us to revise their historical range in eastern North America. We found 12 historical accounts attesting the presence of wolverines in various parts of the Maritime Provinces of Canada, of which 11 were new to contemporary science. According to our results, the eastern limit of the historical range of the wolverine should be extended to include the current jurisdictions of New Brunswick and Nova Scotia. Biological change is the central paradigm of species status assessments. We show that online repositories of public domain literature can now be critical sources of information to assess biological change, including in the case of elusive species. Data mining constitutes a productive tool to uncover useful knowledge hidden in a sea of digitized historical information, and should thus allow researchers and conservationists to more effectively mitigate the problem of shifting baselines.  相似文献   

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Summary Genetic variability and similarity were examined in eight populations of the Kentucky cave beetle Neaphaenops tellkampfii (Coleoptera: Carabidae) using the technique of polyacrylamide gel electrophoresis. Results indicate that N. tellkampfii has high genetic variation within and high genetic similarity among local populations. These results are in sharp contrast to the patterns of low variability and similarity reported for other cave dwelling species in the same region. It is concluded that the differences in genetical population structure among cave species in the Central Kentucky Karst are related to ecological differences among the species.  相似文献   

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In order to emphasize the importance of vegetation mapping for nature conservation purposes a case study in Terceira island (Azores) is presented, in which the importance of the natural vegetation of the eastern slope of Santa Bárbara volcano (which is part of the Site of Community Importance of Santa Bárbara–Pico Alto) is evaluated through the elaboration of its vegetation map. Fourteen (14) different natural vegetation types were identified: grasslands (1 type), peat bogs (2 types), scrubs (2), forests (5), successional vegetation (3) and vegetation of rocky slopes (1). All communities are protected under the Habitat and Species Directive (EC/92/43) and most of them are endemic to the Azores Islands. This fact, together with the significant number of Azorean endemic taxa (18), Macaronesian endemic taxa (5) and species protected under the Habitat and Species Directive (7), gives this area an important conservation value that justifies future protection actions. Vegetation mapping is an important tool for the characterization, evaluation and implementation of managing plans of natural areas of the Azores islands. The use of a floristic-based classification, supported by multivariate analysis and structural data, is an efficient methodology for the construction of these maps. The data collected comprise an important set of information about the distribution and abundance of natural vegetation types and endemic and rare species. This information was not available until now and is indispensable for the elaboration of management plans of Special Zones for Conservation that will be part of the NATURA 2000 network.  相似文献   

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Orangutans are the only great apes found outside of Africa. At present, they occur only on the two large Sunda‐shelf islands of Sumatra and Borneo. Most researchers recognize two separate subspecies, Pongo pygmaeus abelii in Sumatra and P.p. pygmaeus in Borneo.1,2 Relative to other primates, they have a variety of unusual features. These large‐bodied frugivores are among the most solitary of anthropoid primates.3–5 They are also highly dimorphic, with the average body mass (78 kg) of males being more than twice that of females (36 kg).6 Despite its large body size the red ape has more specialized morphological adaptations for arboreality than do the African great apes. Researchers generally recognize sexually mature male orangutans with two physically distinct morphs, a phenomenon described as bimaturism. Males of the relatively smaller morph are known for forcing copulations with adult females.5,7–9.  相似文献   

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Wastewater discharges associated with urbanisations, farming activities and industry may dramatically reduce the ecological health of river ecosystems. During the reconstruction of the Friuli Venezia Giulia region following the 1976 earthquake, a lot of resources were used to build large numbers of wastewater treatment plants to minimize the impact of human activities on lotic ecosystems. Their efficiency is usually assessed through monitoring of the physical and chemical environment near the discharge point. However, discontinuous monitoring of the abiotic environment may fail to detect periodic malfunctioning and do not recognize indirect effects on the ecosystem. We assessed the potential of an alternative approach to assess the impact of wastewater discharges, based on the monitoring of ostracod density, richness and community composition. We repeatedly measured physical, chemical and microbial parameters and collected ostracod samples at stations up- and downstream from wastewater discharge points scattered over a 21-km stretch of the Ledra River (NE Italy). The results indicate that monitoring ostracods is a potentially valuable approach, for two reasons. Communities appeared to be well differentiated even in the small spatial area of this study, indicating that they can provide sufficient resolution to pick up even minor impacts. Secondly, despite the seasonal succession in species composition, spatial differentiation was consistent over time, suggesting that ostracods provide a time-integrated picture of the water quality. The traditional approach failed to detect any consistent impact of wastewater discharges, apart from an ambiguous increase in nutrient levels. The density and/or richness of the ostracod communities was altered by some wastewater discharges, but not by others. We identified a general trend for wastewater discharges to systematically replace regionally rare ostracod species with common species. In particular, the species Ilyocypris inermis was very sensitive to discharges, and may be used as an indicator species for good ecosystem health.  相似文献   

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