Climate Warming and the Recent Treeline Shift in the European Alps: The Role of Geomorphological Factors in High-Altitude Sites

Global warming and the stronger regional temperature trends recently recorded over the European Alps have triggered several biological and physical dynamics in high-altitude environments. We defined the present treeline altitude in three valleys of a region in the western Italian Alps and reconstructed the past treeline position for the last three centuries in a nearly undisturbed site by means of a dendrochronological approach. We found that the treeline altitude in this region is mainly controlled by human impacts and geomorphological factors. The reconstruction of the altitudinal dynamics at the study site reveals that the treeline shifted upwards of 115 m over the period 1901–2000, reaching the altitude of 2505 m in 2000 and 2515 m in 2008. The recent treeline shift and the acceleration of tree colonization rates in the alpine belt can be mainly ascribed to the climatic input. However, we point out the increasing role of geomorphological factors in controlling the future treeline position and colonization patterns in high mountains.     

Chemometric data analysis application to Sparus aurata samples from two offshore farming plants along the Apulian (Italy) coastline

The levels of polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), dioxin-like polychlorobiphenyls (DL-PCBs), non-dioxin-like polychlorobiphenyls (NDL-PCBs), and polybromodiphenyl ethers (PBDEs) in fish collected from two marine offshore farming plants were determined. Each sample was constituted by specimens of the same size collected at the same time in four different seasons along the farming year. The feeds given were of industrial origin and the plants were positioned in two different sites respectively exposed to different environmental characteristics. A chemometric approach was applied to interpret the subtle differences observed in fish body burdens across the three chemical groups taken into consideration. The approach consisted in a stepwise multivariate process including a hierarchical cluster analysis (CA) and a linear discriminant analysis (DA). The two main clusters determined by CA were subjected to the canonical DA, backward and forward selection procedures to select the best discriminative functions. A clear temporal and spatial discrimination was found among the samples. Across the three chemical groups, the monthly separation seemed to depend on the growth process and the main exposure was due to the feed. In addition, the two plants differed significantly from the environmental point of view and the most important discriminating group of chemicals were the NDL-PCBs. The approach resulted really effective in discriminating the subtle differences and in individuating suggestions to improve the quality of culturing conditions.     

Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk from Italian women living in Rome and Venice

The levels of selected polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in human milk samples from the areas of Venice and Rome, primarily in order to characterize the current levels of infant exposure to PCBs and PBDEs due to breast feeding in Italy. Sixteen non-dioxin-like PCBs, including the traditional indicator congeners, and 11 PBDEs, comprising the relevant PBDE-47, PBDE-99, and PBDE-153, were determined. Congeners were selected for analysis according to their relative abundance in human tissues, toxicological relevance, and diffusion in the environment. Dietary habits of the milk donors were recorded by questionnaires; mothers of the Venice area were classified into three groups according to their consumption of local fish, molluscs, and other fishery products. Sigma(16)(PCBs) and Sigma(11)(PBDEs) (ng g(-1) fat) for the areas of Venice and Rome were respectively, 250-390 and 240, and 1.6-2.8 and 4.1. An increase of fish and fishery product consumption could not be associated with an increase of PCB and PBDE levels in milk.     

Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations.     

Acid violet 7 and its biodegradation products induce chromosome aberrations,lipid peroxidation,and cholinesterase inhibition in mouse bone marrow

Introduction  

Acid violet 7 (AV7), mostly used in food, paper, cosmetic, and especially in textile industries, was degraded by Pseudomonas putida mt-2 at concentrations up to 200 mg/l.     

Use of multiple tools to assess the feeding preference of coastal dolphins

The feeding preferences of the coastal dolphins Pontoporia blainvillei and Sotalia guianensis in south-eastern Brazil (21o18′S–22o25′S) were assessed through the prey’s index of relative importance (IRI), total mercury concentration (Hg_tot), and stable isotopic (δ¹⁵N and δ¹³C) to compare their efficiency in the discrimination of prey contribution to the predators’ diet. The IRI was the best tool to describe the dolphins’ preference, while Hg_tot and δ¹⁵N seemed to be efficient as a trophic marker when the diet is made up of prey of varying sizes, as observed in S. guianensis. Both dolphins presented lighter δ¹⁵N than their prey species, which is an unusual pattern. However, as the sample size to isotope ratios analysis was small, especially to the dolphins, the results should be considered with caution, and further studies are necessary to corroborate these findings. The δ¹³C values characterized a typical coastal food chain, confirming the preferential area of these species.     

Spatial and temporal patterns in the feeding behavior of a fiddler crab

Fiddler crabs consume the surficial microphytobenthos around their burrows during low tide. We studied the spatial and temporal feeding patterns in the species Uca uruguayensis by using sequences of digital pictures of feeding pellets accumulation. Data from 61 crabs, feeding without the interference of neighbors, were fitted to different models using Maximum Likelihood and Bayesian approaches. Initial feeding location was independent from the emergence location, and then, crabs continued holding a main feeding direction (clockwise or counterclockwise), suggesting a systematic mechanism that may avoid feeding over already processed sediment. Crabs used at least half of their potential feeding area, but these areas were heterogeneous. Both sexes developed similar feeding areas; however, females were faster and needed less time to feed than males, suggesting that males are time restricted. Our work also highlights the importance of incorporating other underlying mechanisms of the behavior of species into the study of feeding strategies.     

Increased levels of polychlorobiphenyls in Italian women with endometriosis

Endometriosis has been hypothesised to be linked to persistent and toxic organochlorinated chemicals. Dioxins and dioxin-like compounds have in particular been associated with the disease, mainly on the basis of experimental studies. Data in women are conflicting. A case-control study on 80 Italian nulliparous women of reproductive age was carried out to assess whether there is a correlation between the presence of endometriosis and blood levels of polychlorobiphenyls (PCBs), a family of ubiquitary environmental pollutants which comprises congeners with dioxin-like activity. Higher levels of PCBs were found in women with endometriosis. A mean cumulative value of 410 ng g(-1), lipid base, was found in cases versus the value of 250 ng g(-1) observed in the control group (odds ratio for upper tertile 4.0, CI 95% 1.3-13; p = 0.0003). PCB increase involved both dioxin-like (PCBs 105, 118, 156, and 167) and non-dioxin-like congeners (PCBs 101, 138, 153, 170, 180).     

Polychlorobiphenyls and other organochlorine compounds in human follicular fluid

Based on observations in animals, there is an increasing evidence that a number of persistent organochlorine pollutants can alter the endocrine homeostasis, this resulting in toxic effects in particular in the developing organism. However, the role of these chemicals in determining endocrine-related diseases in humans, and possibly a decrease of fertility, is still controversial. Exposure data concerning the human reproductive system are essential for risk assessment. Based on this, the occurrence in follicular fluid of polychlorobiphenyls (PCBs), 2,3,7,8-chlorosubstituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (p,p'-DDT) and its metabolites, and hexachlorobenzene (HCB) was investigated. With respect to PCBs, the sum of the three most abundant congeners (PCBs 138, 153 and 180) was 1230 ng/g, lipid basis (0.37 ng/g, wet weight). Congener distribution profile overlapped what is usually observed in other human tissues, as blood and milk. PCDDs, PCDFs, p,p'-DDT and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane (p,p'-DDD) were below their determination limits. 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE) and HCB were detected in concentrations respectively in the order of 700 and 70 ng/g, lipid basis (approximately 0.2 and approximately 0.02 ng/g, wet weight).     

New patterns of diurnal vertical migration of some deep-water copepods in the Tyrrhenian and Adriatis Seas

The diel vertical migration of copepods from intermdiate water layers of the Tyrrhenian and Adtiatic Seas has been studied on the basis of plankton samples made from depths down to 1000 m, with a Nansen net, mesh size 250 , diameter 113 cm. The species considered display two different patterns of migration: (1) nocturnal ascent, e.g. Pleuromamma abdominalis and Euchaeta acuta; (2) nocturnal descent, e.g. species of the genera Spinocalanus, Scaphocalanus, Temoropia, Mormonilla and Oncaea. These two patterns are compared on the pasis of the dimensions of the species and of their different capacities for active movement. Ililumination is considered to be the most important factor influencing vertical movements. The behaviour of Pleuromamma gracilis is also described, the adult population of which is divided in two discrete sections, each one showing a different pattern of migration.