1,721,001 research outputs found
Faunistic and ecological aspects of Archaeolacerta bedriagae Camerino, 1885 in Sardinia and conservation strategy (Reptilia, Lacertidae)
No full textCross-scale predictions allow the identification of local conservation priorities from atlas data.
No full textFor planning practical measures aimed at biodiversity protection, conservation
priorities must be identified at a local scale. Unfortunately, identifying local
conservation priorities requires high-resolution data on species distribution, and
these are often unavailable. Atlases of species distribution provide data for several
groups of organisms in many different areas but are often too coarse in resolution
to provide valuable information. We explored the possibility of cross-scale modelling
species distributions and we clarified, for the first time, its effect on prioritization
exercises. We used different modelling techniques for scaling down atlas
data for Sardinian reptiles, validated the outcomes with detailed, field-sampled
data, and compared conservation priorities deriving from atlas maps and downscaled
models. Doing this, we obtained as a further result the identification of
priority species and areas for future conservation strategies. Our results encourage
us to experiment further with this approach. Through the downscaling procedure,
we obtain high-resolution models with strong variations in predictive performances,
although most of the models show satisfactory/excellent scores. This testifies
that low-resolution data can be downscaled maintaining low rates of omission
and commission errors. Increasing the resolution of distribution maps used for
prioritization influences the spatial patterns of priority but does not modify the
evaluation of species representation. Overall, we show that atlases can meet the
large demand for distribution data by decision makers if appropriate downscaling
procedures are adopted. In addition, we provide practical instruments for the
conservation of reptiles in Sardinia by identifying priority species and areas that
require strict management
Effects of fire and forest restoration on two sympatric species of Lacertidae (Reptilia) in a Mediterranean ecosystem of Central Italy
No full textEffets des feux et de la restauration forestière sur deux espèces sympatriques de
Lacertidés (Reptiles) dans un écosystème méditerranéen de l’Italie centrale. — Les effets d’un incendie et
de la restauration forestière qui a suivi ont été étudiés sur deux espèces de lézards du genre Podarcis dans
une pinède côtière de l’Italie centrale. Trois stations très proches ont été échantillonnées : deux brûlées, dont
une ayant ensuite fait l’objet de travaux de restauration, et une autre qui n’a pas été atteinte par le feu. Cinq
sessions d’échantillonnage sur la démographie des lézards et leur choix du microhabitat ont été effectuées
entre mars 2003 et mars 2004. P. sicula, espèce pionnière, a été récolté tant dans les stations brûlées que
dans celles qui ne l’ont pas été, tandis que P. muralis n’a été trouvé que dans la forêt intacte. L’abondance de
P. sicula est plus grande dans les zones brûlées. Dans des conditions naturelles, ces espèces sont différenciées
par leur niche spatiale, puisqu’elles utilisent différents niveaux de la végétation, plus élevés pour
P. muralis. L’absence de cette dernière espèce après l’incendie a facilité l’élargissement da le niche spatiale
de P. sicula
Living on the edge: thermoregulation at the niche margin in the Bedriaga’s rock lizard
Full text linkThermoregulation is essential for ectotherms but its relative cost, especially under ongoing climate change, depends on the thermal quality of habitats. Populations at the warm margin of a thermal niche could be negatively affected by environmental temperatures that approach the limits of a species’ thermoregulation capacity. This study aims to define the thermal niche of the Bedriaga’s rock lizard, Archaeolacerta bedriagae, a rock-dwelling species endemic to the Corsica and Sardinia islands (western Mediterranean Sea), and to investigate its thermoregulation effectiveness at the warm edge of its niche. We collected data on climate, body temperature, and microhabitat temperature throughout the species’ range to characterize its thermal niche. We found that A. bedriagae does not occupy the entire climatic space available across its distribution range; rather, it selects temperate climates. Remarkably, thermoregulation effort increases when the habitat thermal quality decreases towards warmer sites. Populations at the warm edge of the thermal niche show the best thermoregulation effectiveness, but they are also more sensitive to the effects of climate change as they may already be at (or beyond) the species’ maximum thermal capacity under the current conditions. We observed such a pattern at the extreme hot side of the thermal niche. This study provides key information on the thermoregulatory response of A. bedriagae to ongoing climate change that can be useful to identify populations facing a higher extinction risk either currently or in the near future
Phylogenetic position of the southern rock lizard Australolacerta australis within the Lacertidae radiation RID F-2663-2011
No full textIl lessico anatolico nell’ambito delle lingue indoeuropee
No full textRevisione dei contributi di R. Gusmani sulle lingue anatoliche del II e I millennio a.C. e aggiornnamento da parte dell'autrice di aspetti e problematiche alla luce dell'avanzamento degli studi sulle singole lingue trattate
Do demographic aspects of neighbouring lizard populations differ? A case study with the common wall lizard, Podarcis muralis
No full textDemographic and morphological aspects of two nearby subpopulations of the common wall lizard (Podarcis
muralis) were studied, by a capture-mark-recapture procedure, at an archaeological site in the surroundings of Rome,
central Italy. In both sites, the births peak was observed in September. Adult sex-ratio was skewed towards males in one
subpopulation, but was close to equality in the other. Morphological characteristics were consistent in the two sites, with
males always exhibiting larger snout-vent-length and head size. Population size and density, computed by a Jolly-Seber
index applied by using POPAN model revealed differences between subpopulations, with lizard density being much higher
in the site with higher habitat heterogeneity and shelter availability. Tail condition was similar between sites. The general implications of these data are discussed
Odonata metacommunity structure in northern ecosystems is driven by temperature and latitude
No full textThe metacommunity concept, defined as a set of local communities connected by species dispersal, provides deep understanding of large-scale ecological processes. The elements of the metacommunity structure (EMS) framework use occurrence data to differentiate among different patterns (i.e., checkerboard, nestedness, species turnover). Metacommunities of tropical Odonata show species turnover following latitude and temperature gradients but there are no such large-scale studies for other regions. We performed EMS analysis with data for the Odonata of British Columbia, Canada, testing the role of five environmental variables (temperature, latitude, altitude, precipitation, landcover typology) in structuring the metacommunities and their turnover. The suborder Anisoptera drives the general pattern, with the communities showing a Clementsian-type response (groups of species that replace each other along the environmental gradients) following temperature and latitude ordering. The Clementsian pattern determined by site temperatures reflects the turnover from a group of cold-adapted species to one of warm-adapted species, separated by many species with more generalised temperature requirements. Similarly, the Clementsian pattern associated with the latitude gradient indicates the substitution of a low-latitude group in the south with a high-latitude group in the north. The sites ordered by landcover did not show significant coherence and turnover. In a macro-scale framework, Odonata species assemblages seem to be sensitive to the climatic and geographic variables of local sites (i.e., temperature and latitude), regardless of the surrounding habitat typology. The role of such variables in shaping the assembly of Odonata communities should be considered in large-scale management and conservation projects
Genetic variation and its evolutionary inmplications in a Mediterranean island endemic lizard
No full textThe peculiar bioclimatic and geographic features of Corso-Sardinian islands may provide an ideal scenario for investigating microevolutionary processes, given their large heterogeneity of environments, which could affect dispersal and gene flow among populations, as well as processes of local adaptation. The genetic variation and differentiation among populations of the endemic lizard Archaeolacerta bedriagae were studied by allozyme electrophoresis at 20 presumptive loci. The genetic structure of this species is characterized by relatively high levels of polymorphism and low differentiation among populations. The pattern of genetic differentiation cannot be explained by genetic drift as a function of geographic distance. Genetic distance data show that genetic variation is distributed into three geographically coherent population groups and suggest a recent (Late Pleistocene) origin for the observed geographic fragmentation. The analysis of environmental correlates of allozymic variation indicates a strong correlation of the Idh-1 locus with climatic variables. The frequency of the Idh-1106 allele is negatively correlated with annual temperature, and positively correlated with annual precipitation. In addition, the observed heterozygosity at this locus decreases towards more arid climatic regimes. The results obtained support the assumption of differential selection acting on Idh-1 allozymes under diverse climates. An association between Idh-1 allozymes and local bioclimatic regimes was also observed for the sympatric lizard Podarcis tiliguerta, suggesting a key role for such selective agents on Idh-1 polymorphism in these two Corso-Sardinian lacertid
Modelling Bedriaga's rock lizard distribution in sardinia: an ensemble approach
No full textMany techniques for predicting species potential distribution were recently developed. Despite the international
interest for these procedures, applications of predictive approaches to the study of Italian fauna distribution are exceptionally
rare. This paper aimed at: (a) detecting climatic exigencies of A. bedriagae in Sardinia; (b) predicting the Archaeolacerta
bedriagae Sardinian potential distribution; (c) identifying the most vulnerable Italian populations of the species. Literature
and field data were utilized as presence records. Six modelling procedures (BIOCLIM, DOMAIN, ENFA, GAM, GLM, and
MAXENT) were adopted. The species climatic requirements were defined using the WorldClim databank for deriving the
environmental predictors. AUC and Kappa values were calculated for models validation. AUC values were compared by using
Anova Monte Carlo. The best four models were combined through the weighted average consensus method for producing a
univocal output. GAM and MAXENT had the best performances (respectively: AUC = 0.93 ± 0.03, Kappa = 0.77 ± 0.08;
AUC = 0.93 ± 0.03, Kappa = 0.78 ± 0.07). Good results were also obtained by GLM and DOMAIN (respectively:
AUC = 0.89 ± 0.04, Kappa = 0.72 ± 0.05; AUC = 0.88 ± 0.04, Kappa = 0.69 ± 0.07). BIOCLIM and ENFA gained
relatively low performances (respectively: AUC = 0.78 ± 0.07, Kappa = 0.57 ± 0.14; AUC = 0.75 ± 0.06; Kappa =
0.49 ± 0.10). In Sardinia A. bedriagae is mainly influenced by seasonality, which causes the evidenced range fragmentation.
Moreover, the general importance of multi-methods approaches and consensus techniques in predicting species distribution
was highlighted
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