Males are faster foragers than females: intersexual differences of foraging behaviour in the Apennine chamois

Availability of food resources and individual characteristics can influence foraging behaviour, which can differ between males and females, leading to different patterns of food/habitat selection. In dimorphic species, females are usually more selective in food choice, show greater bite rates and spend more time foraging than males. We evaluated sexual differences in foraging behaviour in Apennine chamois Rupicapra pyrenaica ornata, during the warm season, before the rut. Both sexes selected nutritious vegetation patches and spent a comparable amount of time feeding. However, males had a significantly greater feeding intensity (bite rate) and a lower search effort for feeding (step rate), as well as they spent more time lying down than females. Females selected foraging sites closer to refuge areas than males. In chamois, sexual size dimorphism is seasonal, being negligible in winter–spring, but increasing to 30–40 % in autumn. Our results suggest that males enhance their energy and mass gain by increasing their food intake rate during the warm season, to face the costs of the mating season (November). Conversely, females seem to prioritize a fine-scale selection of vegetation and the protection of offspring. A great food intake rate of males in the warm season could have developed as a behavioural adaptation leading herbivores to the evolutionary transition from year-round monomorphism to permanent dimorphism, through seasonal dimorphism.     

Sensitivity of a coupled physical–biological model to turbulence: high-frequency simulations in a northern Adriatic station

This paper investigates the impacts of different turbulence models on the biological state at an ocean station in the northern Adriatic sea, named S3, comparing them with other uncertainties inherent to coupled physical–biological simulations. The numerical tool is a 1-D model resulting from the coupling of two advanced numerical models. The hydrodynamic part is modelled using the General Ocean Turbulence Model (www.gotm.net), in a version adopting state-of-the-art second-moment Turbulence Closure Models (TCMs). Marine biogeochemistry is parameterized with the Biogeochemical Flux Model (http://www.bo.ingv.it/bfm), which is a direct descendant of ERSEM (European Regional Sea Ecosystem Model). Results, obtained by forcing the model with hourly wind and solar radiation data and assimilating salinity casts, are compared against monthly observations made at the station during 2000–2001. Provided that modern second-moment TCMs are employed, the comparisons indicate that both the physical and the biological dynamics are relatively insensitive to the choice of the particular scheme adopted, suggesting that TCMs have finally ‘converged’ in recent years. As a further example, the choice of the nutrient boundary conditions has an impact on the system evolution that is more significant than the choice of the specific TCM, therefore representing a possible limitation of the 1-D model applied to stations located in a Region of Freshwater Influence. The 1-D model simulates the onset and intensity of the spring–summer bloom quite well, although the duration of the bloom is not as prolonged as in the data. Since local dynamics appears unable to sustain the bloom conditions well into summer, phytoplankton at the station was most likely influenced by river input or advection processes, an aspect that was not found when the S3 behaviour was adequately modelled using climatological forcings. When the focus is in predicting high-frequency dynamics, it is more likely that lateral advection cannot be neglected. While the physical state can be satisfactorily estimated at these short time scales, the accurate estimation of the biological state in coastal regions still appears as rather elusive.     

Pesticide and plasticizer residues in bergamot essential oils from Calabria (Italy)

Organophosphorus and organochlorine pesticides, phosphorated plasticizers, chloroparaffins and phthalate esters contamination in bergamot essential oils produced in Calabria in the crop years 1999-2000 was studied by HRGC in connection with detectors FPD, ECD, MS. Residues of dicofol and tetradifon were found in oils from both crop years. The mean dicofol concentration was 0.26 mg/l in samples from 1999 and 0.20 mg/l in those from 2000; the mean tetradifon content was 0.06 mg/l for both the crop years. Among plasticizers, residues of diisobutyl phthalate, di-n-butyl phthalate, and bis(2-ethylhexyl) phthalate were found in samples from crop years 1999 and 2000, the mean content were 1.22 and 1.23 mg/l, 1.51 and 1.65 mg/l, 1.38 and 1.42 mg/l respectively.     

Adequacy of ecosystem models

A formal approach is developed to assess the adequacy of mathematical models to represent a given ecosystem. The procedure is based on the hypothesis that two or several models of an environment can be compared by using a vectorial approach: several model properties are analyzed and related to the model's capability to simulate the observed behaviour and to describe the ecosystem processes. The models are thus ordered from the standpoint of their adequacy. One preliminary model, a more recent one, and four lumped versions of the latter have been tested for adequacy. These models were developed by Wiegert and they describe the behaviour of an algal-fly community energetics in a thermal spring. Results obtained by our procedure agree with Wiegert's but some new points have been emphasized.     

Ancient settlement dynamics and predictive archaeological models for the Metapontum coastal area in Basilicata,southern Italy: from geomorphological survey to spatial analysis

In the ancient territory of the Greek settlement of Metaponto and its Chora (Ionian sector of Basilicata, southern Italy) geomorphological mapping, GIS-supported statistics, and landform topographic features were investigated and combined to extract settlement rules and site dynamics. Analyses of environmental dynamics as well as of spatial and temporal settlement evolution were carried through an integrated approach that, starting from a detailed geomorphological analysis, tried to extract the spatial relationships between archaeological site locations and landform/landscape features. Spatial analysis was used to investigate the relationships between environmental parameters and archaeological sites. The advantages to develop a predictive model using Archeological Spatial Evaluation (ASE) analysis lay in the possibility to deeply study the relationships between man and the environment. In the present study, the analysis was carried out in a pioneering way in the ~400 km² Metaponto territory in order to robustly validate - in the aftermath data - human and territorial dynamics. A model describing interactions between sites and parameters such as elevation, slope, aspect, landforms, land use, and distances from rivers was constructed. Sensibility maps were produced, which will help archaeologists to know how many and which are the parameters increasing the probability to find new archaeological sites as well as how the main geomorphological features of the study area, contextualized within the most likely paleoclimate scenario, affect ancient site arrangement though time. The preferential occupation of mid-altitude marine terraces, and the consequence spreading of agriculture on these territories, is likely due to the existence of well-developed soil profiles on them. Clearly colonists recognized that on these landform units there were the better conditions for the development of massive agricultural practices: since the SP age (4,1 to 2,0 Kyr B.P.) the settlers expands inland looking for most fertile territories as well as for areas sufficiently protected (being far away from the coast). The increase in farmhouses on the top of marine terraces from the FC up to EC-EE periods and the modifications of settlement distribution (gradual abandonment of alluvial) in the Metaponto area is likely related to the acceleration of alluvial processes. The progressive decrease of human occupation during the Hellenistic up to the Roman Age is clearly consequence of the Roman conquest. However, a role played by the increase in flooding occurrence in the coastal plain/floodplains of the main rivers in triggering the abandonment of these territories and marking the beginning of the decadent phases should not be neglected. Productive areas (locally associated to farmhouses) are preferential set along the fluvial incisions (sometime associated to farmhouses), thus implying that productive area setting is strongly linked to the presence of rivers, and of their lower rank tributaries, both as an intrinsic need of manufacturing and to facilitate the spreading of products. From the Classical to the Hellenistic Age until the Roman Age, Necropolis are spread in the entire area, from marine terraces to alluvial plain. On the other hand, Sacred areas - which appearance is recorded starting from the Colony Foundation Age - exhibits a settlement continuity in the study area starting from this time up to the entire Roman period, and the sacred areas setting is strictly associated to the category of Settlement.