Search results for "nature"
showing 10 items of 1564 documents
La vegetazione del litorale di Manfria, presso Gela (Sicilia), area soggetta a vincolo archeologico.
2000
The results of a phytosociological investigation about a coastal area of S. Sicily, close to Gela, are presented. The coexistence of several lithological substrata, as well as the particular climatic conditions of this area, gives rise to a noteworthy floristic and vegetational biodiversity. As matter of fact, a set of N. African species are here localized, taking part to peculiar vegetation types, sometimes exclusive of this sicilian coast-stretch. The observed plant communities are represented by psammophilous associations of Cakiletea maritimae, Ammophiletea and Malcolmietalia, salt-marsh vegetation of Sarcocornietea and Phragmito-Magnocericetea, halophilous rupicolous shrublands of Crit…
2015
Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…
Stopover strategies in birds: a review of methods for estimating stopover length
1999
This study categorizes and reviews methods used to estimate stopover length in migratory birds. Stopover length is an important variable in analysing migration strategies. The analysis of the stopover pattern of migratory birds typically attempts to investigate variability in the number of stopovers and in the length of time spent at stopover sites in relation to species, age, sex and body condition. Although the number of capture-recapture studies analysing stopover length has increased substantially, most are analysed using the simple last-first capture method which gives biased estimates. The use of mathematical models to calculate stopover length is uncommon. Most researchers assume hom…
Characterisation of the magmatic signature in gas emissions from Turrialba Volcano, Costa Rica
2014
The equilibrium composition of volcanic gases with their magma is often overprinted by interaction with a shallow hydrothermal system. Identifying the magmatic signature of volcanic gases is critical to relate their composition to properties of the magma (temperature, fO2, gas-melt segregation depth). We report measurements of the chemical composition and flux of the major gas species emitted from Turrialba Volcano during March 2013. Measurements were made of two vents in the summit region, one of which opened in 2010 and the other in 2012. We determined an average SO2 flux of 5.2 ± 1.9 kg s-1 using scanning ultraviolet spectroscopy, and molar proportions of H2O, CO2, SO2, HCl, CO and H2 ga…
Regulating Internet Trade in CITES Species
2013
International trade in species that are or may be endangered by collection from the wild is regulated under the Convention on International Trade in Endangered Species of wild fauna and flora (CITES) for 176 member States (Parties). Internet commerce is a relatively new route for such trade. In 2007, the CITES Secretariat asked Parties to collect information on internet wildlife trade and report problems and implemented regulations. The reports indicated it was difficult to even approximate the influence of e-commerce on CITES-listed species (CITES Secretariat 2009). We report a case study in which we quantified international transactions over an internet auction site of CITES-listed cacti …
PRIMO LEVI E LA QUESTIONE DELL’ANIMALITÀ
2020
The approach of man and animal in Levi’s work can lead to some simplifications. We could think of a naturalization operation: man is one of many animals. Or, on the contrary, we could think of a culturalization: the animal is a social being. In reality, the ontological principle on which Levi’s thinking and writing are based is that of analogy. Assuming the hypothesis of the anthropologist Philippe Descola, this essay proposes an analogical reading of Levi. Focusing on a precise story, Censura in Bitinia, I will try to discuss this interpretative hypothesis.
Social impacts of biodiversity offsetting: A review
2022
Biodiversity offsetting is the widely studied last step of the mitigation hierarchy. Despite numerous studies and the methodological development completed for biodiversity calculations, the human aspect remains unsolved. Biodiversity conservation is typically governed at national or state levels, but the harm caused to biodiversity as well as people occurs locally. In biodiversity offsetting, biodiversity values can be relocated far from the original area, but relocating the values people hold regarding their nearby nature may not be possible. Acknowledging the local people's hopes and values may further complicate biodiversity offsetting, therefore it emphasises even more the need to avoid…
Eresus kollari (Araneae: Eresidae) calls for heathland management
2011
Northwest Europe’s largest heather-dominated sandy habitats are located in the nature reserve Lu¨neburgerHeide, Germany. Yet, even these appear to be losing their ability to support some of their stenotopic species such as theladybird spider, Eresus kollari Rossi 1846, and are thus becoming increasingly important for the preservation of thesespecies. The habitat requirements of this endangered spider species were investigated in order to obtain data that will helpstabilize the last remnants of the species’ population in northwest Germany. Several heathland habitats were surveyed bypitfall trapping during the mate-search period of the males. Two statistical methods were applied: logistic reg…
Quantifying the Indicator Power of an Indicator Species
2009
Biodiversity indicator species are needed for classifying biotopes and sites for conservation, and a number of methods have been developed for determining indicator species for this purpose. Nevertheless, in addition to site classification, there is sometimes a need to define an indicator species that indicates the occurrence of another species. For example, when a species of interest (target species) is difficult to detect or identify, a reliable indicator species can function as a tool that saves time and money. We derived a method that provides a quantitative measure of the indicator power (IP) of an indicator species for the target species or any species assemblage. We calculated the me…
The Managing and Restoring of Degraded Land in Post-Mining Areas
2022
Mining is an important branch of the economy, providing raw materials necessary for the economic and civilization development of the country [...]