Does lake age affect zooplankton diversity in Mediterranean lakes and reservoirs? A case study from southern Italy

Zooplankton assemblages of 51 lacustrine environments located in the middle of the Mediterranean Region were analysed to evaluate the existence of an ‘age effect’ in determining their structure. The analysed datasets refer to two different geographic areas, one comprising 30 natural and artificial lakes in Sicily and the other an arrangement of 21 analogous aquatic ecosystems located at the bottom of the Italian Peninsula, a more pristine area called Southern Apennine region. Most of the natural lakes are of post-glacial origin. The artificial lakes in both datasets were built in the last century and offer the opportunity to evaluate the possible short-term effects of ageing on the structure of their zooplankton. A comparison of assemblages in the two regions by PERMANOVA and nMDS revealed that they are quite different; therefore they were analysed separately. An explorative analysis on the possible relationship between biological data and environmental data (including lake age) was performed on both datasets using DISTLM. The presence of an ‘age effect’ emerged only in the subset of artificial lakes of the Southern Apennine region; accordingly it was tested more in detail with an a posteriori PERMANOVA analysis in the subset of reservoirs that resulted positive in the first test. SIMPER allowed us to single out the main species responsible of changes in the zooplankton along the selected age groups. No age effect was evident in the Sicilian water bodies, where other variables, such as conductivity, trophic state, urbanisation and water level fluctuations proved to have a major role in shaping zooplankton assemblages. The results showed that the age effect is: (i) detectable only at a time scale of decades; (ii) masked by the human impact in the watershed.     

Reed die-back in southern Europe? A case study from Central Italy

Common reed die-back is a widely investigated phenomenon in Central Europe, not frequently recorded in S-European areas and almost unknown in the Mediterranean Basin. Symptoms of reed decline recently observed in the Italian Peninsula provided the starting point for a detailed investigation on a reed population in one of the largest freshwater ecosystems in Central Italy. The analyses were conducted over two vegetative seasons in 19 plots at seven locations. A set of 13 morphologic and phenologic reed traits were screened, monitored and statistically analysed. The data indicated the presence of the reed die-back syndrome in a wet Mediterranean ecosystem and enabled us to highlight a set of usable traits to detect the condition of decline. Among them, the stem height and diameter, the number of nodes, the relative growth rate and the lateral root diameter resulted the most significant factors highlighting the declining condition. Some environmental characteristics of the reed stands were also taken into account. The period of submersion and the presence of standing litter emerged as important features of the stands, strictly related to the degree of decline in the population. The results draw attention to the risk, in southern Europe too, of the loss of an ecosystem which plays an important role in biodiversity conservation.     

Do agri-environmental schemes contribute to high nature value farmland? A case study in Emilia-Romagna (Italy)

The objective of the paper is to determine whether the agri-environmental schemes included in the rural development programme of Emilia-Romagna (Italy) have played a role in enhancing the nature value of farmland in that region. An indicator is developed for biodiversity friendly farming practices (BFFP) and its level and distribution at the municipality level is measured, using data derived from the two last national agricultural censuses, year 2000 and 2010. Thereafter, the relationship between BFFP and participation in rural development measures is analysed by way of spatial econometric techniques. The main result of the paper are consistent with the expectation that RDPs have an impact on how BFFP changes. However, measures supporting organic farming contribute to the evolution of its distribution in a positive manner, whilst the other measures investigated, such as integrated production, do not. The paper also highlights the fact that these effects have significant spatial correlations.     

Can taxonomic distinctness assess anthropogenic impacts in inland waters? A case study from a Mediterranean river basin

1. It is increasingly recognised that adequate measures of biodiversity should include information on the ‘relatedness’ of species within ecological assemblages, or the phylogenetic levels at which diversity is expressed. Taxonomic distinctness measures provide a series of indices to achieve this, which are independent of sample size. Taxonomic distinctness has been employed widely in marine systems, where it has been suggested that this index can provide a reliable measure of anthropogenic impact. 2. We tested the behaviour of three related taxonomic distinctiveness indices (Average Taxonomic Distinctness, Δ⁺; Variation in Taxonomic Distinctness, Λ⁺; and Total Taxonomic Distinctness, sΔ⁺) in relation to putative levels of anthropogenic impact in inland waters and their potential utility in environmental monitoring, using an extensive data set for aquatic beetles from the south‐east of the Iberian Peninsula. 3. Taxonomic distinctness measures were not able to identify human disturbance effects and there were no clear relationships between these new biodiversity measures and the disturbance level recorded at individual localities. Furthermore, the taxonomic distinctness measures used were apparently less sensitive to the effects of anthropogenic impact than other diversity metrics, such as species richness and rarity. 4. We conclude that taxonomic distinctness indices may not always perform as well as other metrics in the assessment of environmental quality. In addition, taxonomic distinctness measure should be interpreted with caution, as their performance and ability to detect anthropogenic disturbance may depend on the phylogenetic structure of sampled taxa within a region, and their evolutionary and ecological history.     

Wild aromatic plants bioactivity: a function of their (poly)phenol seasonality? A case study from Mediterranean area

Wild medicinal and aromatic plants are in the market as herbal raw or processed and packaged materials, playing, even today, a strategic role in the production of plant-based products. Indeed, their content in active ingredients, mainly specialized secondary metabolites, is not constant; it undergoes significant seasonal variations, as abiotic stress heavily affects secondary metabolism network. The present review deals with the seasonality influence on the polyphenolic composition on antioxidant and anti-inflammatory properties of medicinal and aromatic plants. To this aim, firstly the factors influencing the content of active ingredients in a plant drug will be discussed, and, in particular, the increased occurrence of phenols as a response to abiotic stress. In the last part of the review a brief reference will be made to four meaningful case studies, which involve wild medicinal aromatic herbs, native to the Mediterranean area: Calamintha nepeta L. Savi, Foeniculum vulgare Mill., Ruta graveolens L. and Thymus longicaulis C. Presl. These species, grown in the same geographical area and collected at the same harvesting time, showed a great variability in phenol constituents throughout the year. The comparison among data acquired clearly evidences that the seasonal variation in polyphenols’ occurrence and amount leads to a more/less pronounced antioxidant and anti-inflammatory activity of the hydroalcoholic extract therefrom. It is worth of note that the presence of the same metabolite, but in different phytochemical complexes, could result in different biological activities.     

Impacts of alien plants and man‐made disturbance on soil‐growing bryophyte and lichen diversity in coastal areas of Sardinia (Italy)

Abstract

Seventy phytosociological relevés were performed in 1 m × 1 m plots at 14 study sites spread along sandy shores in northern and southern Sardinia (Italy). The plots were selected in different habitat types (open dunes, native Juniperus woodlands, maquis, and plantations with Acacia, Eucalyptus and Pinus) according to a stratified sampling method in order to investigate impacts deriving from different levels of Carpobrotus spp. cover, dry litter from exotic trees, and other disturbance types. The quantile regression and logistic regression analyses revealed that the reduction in the amount of bryophyte and lichen cover on sand dunes of the study area is caused either by a high cover of Carpobrotus spp. mats or by a high cover of dry exotic litter in dense, unmanaged or poorly managed forest plantations. Additional detrimental effects are often driven by other kinds of man‐made disturbances. Forest management in the coastal areas of Sardinia should be gradually modified to take into account the conservation of bryophytes and lichens. Some of the biological indicators used are quite widespread in the Mediterranean coastal habitats or are exclusively associated with sand dunes; therefore, they can also be conveniently used as indicators of biological impacts in other countries or islands of the same biogeographical region.     

Tree age,site and climate controls on tree ring cellulose δ18O: A case study on oak trees from south-western France

A main concern of dendroclimatic reconstruction is to distinguish in the tree ring proxy the influence of the climate variables of interest from other controlling factors. In order to investigate age, site and climate controls on tree ring width and cellulose δ¹⁸O, measurements have been performed in nearby groups of young (145 years old) and older (310–405 years old) oak trees in south-western France, covering the period 1860–2010.Within a given site, inter-tree deviations are small, pointing to a common climatic signal. Despite a similar inter-annual variability, the average level of cellulose δ¹⁸O in the young tree group is ∼0.8‰ higher than in the old trees. Such offsets might be caused by different soil properties and differences in the fraction of the source water used by trees from different depths. The δ¹⁸O of water in the top soil layer is directly related to the current growing season precipitation, while deeper water can have a lower and more constant δ¹⁸O. Local cave drip waters at 10 m depth indeed show a constant isotopic composition, which corresponds to pluri-annual mean precipitation.A 2‰ increasing trend is observed in cellulose δ¹⁸O of young trees in the first 30 years of growth, during a period when no trend is visible in older trees. This increase can be quantitatively explained by humidity gradients under the forest canopy, and a changing microclimate around the crown as trees grow higher.While relationships between tree ring width and climate appear complex, the isotopic composition of cellulose is strongly correlated with summer maximum temperature, relative humidity and evapotranspiration (r ≈ 0.70). Weaker correlations (r ≈ 0.40) are identified with precipitation δ¹⁸O from a 15-year long local record and from the REMOiso model output. These results imply that leaf water enrichment has a stronger control on the inter-annual variability of cellulose δ¹⁸O than the δ¹⁸O of precipitation.This study demonstrates the suitability of oak tree ring cellulose δ¹⁸O for reconstructing past summer climate variability in south-western France, provided that the sampling and pooling strategy accounts for the fact that trees from different sites and of different age can introduce non-climatic signals.     

Familial malignant mesothelioma: A population-based study in Central Italy (1980–2012)

Malignant mesothelioma is a sporadic cancer linked to asbestos exposure. Its occurrence among blood relatives (familial mesothelioma) may point to genetic susceptibility or shared exposures. The burden of the familial disease is unknown. The aims of the study were to assess at population level the proportion of familial mesotheliomas among all mesotheliomas and to investigate the family history of cancer among relatives of mesothelioma cases. We actively searched familial clusters based on a mesothelioma registry from central Italy (5.5 million people, 10% of the Italian population) of the National Mesothelioma Register network (ReNaM) as well as a pathology-based archive. Among 997 incident mesotheliomas recorded in a 32-year-period (1980–2012), we detected 13 clusters and 34 familial cases, accounting for 3.4% of all mesotheliomas. The most common clusters where those with affected siblings and unaffected parents. Asbestos exposure was occupational (n = 7 clusters), household (n = 2), environmental (n = 1), or not attributable for insufficient information (n = 3). There were 25 additional cancers in nine families. Some were cancer sites for which there is sufficient evidence (lung and larynx) or limited evidence (stomach and colon) of causal association with asbestos. The results suggest potential genetic recessive effects in mesothelioma that interact with asbestos exposure, but it is not possible to estimate the specific proportion attributable to each of these components.     

Importance of dose‐response model form in probabilistic risk assessment: A case study of health effects from methylmercury in fish

We compared the effect of uncertainty in dose‐response model form on health risk estimates to the effect of uncertainty and variability in exposure. We used three different dose‐response models to characterize neurological effects in children exposed in utero to methylmercury, and applied these models to calculate risks to a native population exposed to potentially contaminated fish from a reservoir in British Columbia. Uncertainty in model form was explicitly incorporated into the risk estimates. The selection of dose‐response model strongly influenced both mean risk estimates and distributions of risk, and had a much greater impact than altering exposure distributions. We conclude that incorporating uncertainty in dose‐response model form is at least as important as accounting for variability and uncertainty in exposure parameters in probabilistic risk assessment.     

Identifying prehistoric collected wild plants: A case study from late bronze age settlements in the french alps (Grésine, Bourget Lake, Savoie)

The late Bronze Age lakeshore settlements of Grésine (French Alps) have yielded archaeobotanical evidence of 14 cultivated and 153 wild plants. Some of the wild taxa may have been collected, but many are probably here by chance. Three criteria are used as evidence for human transport and manipulation of wild plant remains: number of items, fragmentation, and carbonization. Relations between these criteria and known ethnobotanical properties of the identified plants are statistically analyzed. Results display good evidence of the gathering of edible wild fruits and seeds. Other gathering practices are not documented. Edible fruits and seeds seem to have been gathered mainly from ruderal spring weed communities and, possibly, from forest clearances and hedge communities. Fragmentation appears to be less of a discriminating factor than number of plant remains and carbonization.     

Are changes in body dimensions of adult females from Italy (Sardinia and Latium) related to secular trend?

This paper presents secular changes in height, weight, sitting height, relative sitting height, BMI and estimated lower limb length in two samples of Italian adult females from Sardinia (Cagliari) and Latium (Rieti). The samples consist of 579 healthy women from the province of Cagliari and 138 from the town of Rieti, aged 20.0-39.9 years, measured in the period 2003-2006. The women were divided into four 5-year age groups. The anthropometric variables were considered according to different socioeconomic status (SES) in the Cagliari sample, while the Rieti sample was considered as a whole, as the SES was homogeneous. ANOVA results suggest that the secular trend was very slow or had come to a halt in the Rieti sample but continues in the Cagliari sample, as shown by the statistically significant differences for estimated lower limb length (p≤0.02), and relative sitting height (p≤0.05). However, these differences disappear after ANCOVA with sibship size and socioeconomic status controlled for, suggesting that they depend mainly on the composition of the Cagliari sample in terms of SES. Therefore, it can be hypothesised that the secular trend might be very slow or has stopped in the Cagliari subsamples homogeneous for SES.     

When is enough,enough in phylogenetics? A case in point from Hordeum (Poaceae)

Direct optimization was used to reconstruct the phylogeny of the 26 diploid taxa included in the genus Hordeum. The total data set was composed of 16 nucleotide sequence regions from the nuclear as well as the plastid genome. The nine nuclear regions were from single‐copy, protein coding genes located on six of the seven chromosome pairs in the diploid H. vulgare genome. The seven plastid regions comprise protein coding genes as well as intergenic regions. Studies of character congruence between data partitions showed no correlation between chromosomal location and congruence among the nuclear sequences and a level of congruence among the plastid sequences comparable with the level among the nuclear sequences. Combined analysis of all data resolved the phylogeny completely with most clades being robust and well supported. However, due to incongruence among data partitions some relationships are still and likely to remain ambiguously inferred. Rather than adding still more genes to the phylogenetic analyses, patterns of incongruence may be better explored by adding data from multiple specimens per taxon. For some species relationships the plastid data appear positively misleading, emphasizing the need for caution if plastid data are the only or dominant type of data used for phylogenetic reconstruction and subsequent re‐classification.
© The Willi Hennig Society 2011.     

Growth charts of head length and breadth for regional areas? A study in Sardinia (Italy)

There exist few standards of head length and breadth from childhood to adulthood in Europoid populations. Moreover, such standards are based on samples that cannot be used as references for all populations since they were taken from different ethnic groups and from different periods. The aims of this study were: (1) to test whether standards derived from North Americans of European extraction can be used to assess the Sardinian population; and (2) to produce growth charts for head length and breadth for Sardinian males and females from 3 to 22 years of age.The cross sectional sample consisted of 9,721 subjects of Sardinian origin (4,884 males and 4,837 females), aged 3–22 years, measured from 1998 to 2008. Growth percentiles were produced with the LMS method. The mean values for each sex in each age class (3–18 years) are almost always significantly lower for both head length and breadth than the corresponding North American values. The exceptions are the head length of boys of 14 years and girls of 16–18 years where values for Sardinians are lower, but not significantly so. The results show that the North American standards are not appropriate for the assessment of Sardinian children. For the Sardinian population, specific regional growth charts should be used to correctly evaluate the normal range and the cut-off points of the extreme percentiles.     

Filling of eco-climatological niches in a polyploid complex – A case study in the plant genus Leucanthemum Mill. (Compositae,Anthemideae) from the Iberian Peninsula

In order to assess the effects of polyploidisation on distribution patterns of species in a polyploid complex, we compared potential and actual distribution ranges of representatives from the genus Leucanthemum Mill. (Compositae, Anthemideae), which occur on the Iberian Peninsula with 20 taxa spanning ploidy levels between 2n = 2x = 18 and 2n = 22x = 198. Actual distribution ranges of taxa were derived from geo-referenced herbarium specimens by defining buffer circles around the collection localities to account for geographical uncertainties and haphazardness of specimen collecting. Eco-climatologically potential ranges were modelled with the maximum entropy method (Maxent) based on the actual distributions. By comparison of sizes of realised and eco-climatologically potential areas for each taxon we computed taxon-specific overlap indices that express the filling of eco-climatological niches. The correlation between overlap indices and ploidy levels was tested by Spearman's rank correlation coefficient. We observed a significant negative correlation between ploidy level and sizes of realised distribution ranges and no significant correlation of ploidy level and sizes of potential ranges. Finally, we found that diploid and low-ploidy taxa are filling their potential eco-climatological distribution ranges more exhaustively than highly polyploid taxa. Assuming that ascending polyploidisation is the prevailing mode compared to descending polyploidisation, our results demonstrate that the distribution patterns of members of the Leucanthemum polyploid complex on the Iberian Peninsula are mainly influenced by the age of taxa and not by ecological advantages or disadvantages connected with polyploidy.     

Does reproductive success increase with age or with size in species with indeterminate growth? A case study using sand lizards (Lacerta agilis)

Most data on determinants of reproductive success (RS) and reproductive tactics are correlational in nature, and hence cannot be used to infer causation. Consistent patterns-such as an increase in RS with age, as seen in many types of organisms-may result from diverse underlying mechanisms. Ontogenetic increases in RS in mammals and birds may be due largely to direct effects of age (via learning, etc.) but our analyses show that apparently analogous ontogenetic shifts in reproductive tactics and increases in RS in sand lizards (Lacerta agilis) are actually due to ontogenetic changes in body size. When size effects are removed, age exerts very little effect on either reproductive behaviour or RS in either sex. In many taxa, both age and body size may exert important effects on reproductive biology, and disentangling these effects should be a focus of further research.     

Do anthropogenic corridors homogenize plant communities at a local scale? A case studied in Tenerife (Canary Islands)

Biological homogenization is defined as a process that occurs when native species are replaced by common and dominant exotic species or due to depletion and expansion of native species, reducing the beta diversity between areas or habitats. Islands are particularly vulnerable to plant invasion, and as a consequence, homogenization is a process that can become faster and more intense in islands than in continental areas. We recorded vascular plant species composition in roadside communities along a strong altitudinal gradient using plots beside the road and at two distances from the road (0–50 and 50–100 m). We analyzed the results separately for each group of plots with a Detrended Correspondence Analysis (DCA) including and excluding exotic species. The results revealed that where exotic species were most abundant, i.e., at the road edge, they can create an effect of floristic homogenization where three similar roads are compared. At a distance of >50 m from the road, where exotic species are less frequent, this effect has already disappeared, indicating that it is a local phenomenon, closely related to the highly disturbed roadside environment. Furthermore, floristic homogenization seems to be more important at higher altitudes (>1000 m), probably related to higher diversity in native plant communities and lower levels of human disturbances. Roads allow humans to reach relatively remote and sometimes well-conserved areas, and, at the same time, facilitate the spread of exotic plants and the most common native species which can locally create floristic homogenization in roadside communities on this oceanic island. A deeper understanding of the effects of these anthropogenic corridors at the local and regional scales is therefore required to integrate road planning and management with the aim of conserving the value of the natural areas.     

The social origin of open-hearth structures in Mesolithic. A case study of the habitation “A” at site Paliwodzizna 29 (central Poland)

The subject of the research described in this article is a collection of flint artefacts obtained in the course of an exploration of one of the Mesolithic assemblages from site 29 in Paliwodzizna in Central Poland. The artefacts were subjected to a typological-technological analysis, a use-wear analysis and multi-faceted spatial analyses. As a result of the studies it was concluded that the collection might be affiliated with the Komornica culture and dated to the Atlantic period, which was confirmed by radiocarbon dating. The functional structure of the collection and the spatial organisation of the camp indicate that it was a hunting camp briefly used by a small group of people. The structure was compared with other camps of similar function from the region and the type of mobility of the hunter-gatherer groups that were using the site was considered.