Sandro Strumia

Post-fire bryophyte dynamics in Mediterranean vegetation

Bryophyte dynamics after fire in the Mediterranean macchia of Southern Italy was studied both by diachronic and synchronic approaches. Changes of bryophyte cover and spe- cies composition were found in relation to both age and fire intensity. During the first 2 yr after fire, bryophytes dominated the plots which had experienced the highest fire intensity while herbs were dominant in plots affected by lighter fires. Pioneer species, such as Funaria hygrometrica, Barbula convoluta and Bryum dunense, characterized recent intense fires, whereas Bryum torquescens, B. radiculosum and B. ruderale were dominant after less intense burning. Pleurochaete squarrosa, Tortula ruraliformis and Tortella flavovirens domi- nated intermediate successional stages. Pleurocarpous mosses were dominant only in the older closed stands. Different patterns of regeneration strategies were described: spores dominated early stages of intense fire, while vegetative propagules characterized later successional stages and less severely burned areas. Although bryophytes usually have a low abundance in Mediterranean vegetation, their role in post-fire vegetation dynamics may be locally enhanced according to burning conditions.

Trace element accumulation in Pseudevernia furfuracea (L.) Zopf exposed in Italy’s so called Triangle of Death.

Trace element accumulation in the lichen Pseudevernia furfuracea (L.) Zopf was studied in the district of Acerra (province of Naples, southern Italy), one of the points forming Italys Triangle of Death. P. furfuracea thalli, collected from Mt. Faito (province of Naples), were transplanted and exposed in bags at different sites in Acerra district, classified into three different site types (urban, rural and industrial). We aimed to test the hypothesis that P. furfuracea, when transplanted in the district of Acerra, would respond to air pollution accumulating trace elements and that element concentrations in the exposed lichens were different in relation to the three different environments, characterised by different pollution sources. Samples were exposed for six months, periodically collected and examined by ICP MS spectrometer assays to measure concentrations of 10 trace elements (Al, As, Cd, Cr, Cu, Fe, Mn, Pb, V and Zn). The exposed samples showed increases in concentrations of all the examined elements; the trace element concentrations were evaluated by calculating exposed to control (EC) ratios, for each site and each trace element, to better understand the accumulation rates. EC ratios were evaluated after 3 and 6 month exposures, at the end of spring and summer respectively: 6 month EC values were the highest. The urban sites showed EC ratios generally higher than industrial and rural; the most accumulated elements were Pb and Cu (at the urban sites), Cu and Zn (at the industrial sites), and Cu and As (at the rural sites). The chemical data were then processed using a multivariate approach (ordination, PCA) to better understand environmental gradients. Bioaccumulation data and PCA analysis showed the sampling sites separated by different trace element abundance. Trace element abundance patterns in the three site types are discussed in relation to the land use and the pollution sources.

Traffic pollution affects tree-ring width and isotopic composition of Pinus pinea

This study presents new evidence that radiocarbon, combined with dendrochronological and stable isotopes analysis in tree rings and needles, can help to better understand the influence of pollution on trees. Pinus pinea individuals, adjacent to main roads in the urban area of Caserta (South Italy) and exposed to large amounts of traffic exhaust since 1980, were sampled and the time-related trend in the growth residuals was estimated. We found a consistent decrease in the ring width starting from 1980, with a slight increase in delta(13)C value, which was considered to be a consequence of environmental stress. No clear pattern was identified in delta(15)N, while an increasing effect of the fossil fuel dilution on the atmospheric bomb-enriched (14)C background was detected in tree rings, possibly as a consequence of the increase in traffic exhausts. Our findings suggested that radiocarbon is a very sensitive tool to investigate small-scale (i.e. traffic exhaust at the level crossing) and large-scale (urban area pollution) induced disturbances.

Are Red Lists really useful for plant conservation? The New Red List of the Italian Flora in the perspective of national conservation policies

“The New Red List of the Italian Flora” includes all the Italian policy species and other species of known conservation concerns for a total of 400 taxa, 65% of which are threatened with extinction. The Red List is based on a huge georeferenced data-set useful for conservation purposes.

Ultrastructural effects of trace elements and environmental pollution in Italian “Triangle of Death” on Pseudevernia furfuracea (L.) Zopf

Abstract The lichen Pseudevernia furfuracea was exposed to environmental trace elements in the district of Acerra (province of Naples, southern Italy), one of the points forming Italys “Triangle of Death”. P. furfuracea thalli were exposed in bags at different sites for 6 months, periodically collected and examined by transmission electron microscopy (TEM) to assess ultrastructural changes. An our earlier study demonstrated that these exposed lichens were strongly contaminated by trace elements (Sorbo S, Aprile G, Strumia S, Castaldo Cobianchi R, Leone A, et al. 2008. Trace element accumulation in P. furfuracea (L.) Zopf exposed in Italys so-called Triangle of Death. Sci Total Environ 407: 647–654.). The algal cells were more affected than the fungal symbiont. Exposition at urban sites gave the most frequent changes. Four trace elements (Cd, Pb, Cu and Zn) were used to study the effects of ultrastructural trace element both in field and in vitro treatments. The lichen developed comparable ultrastructural changes when exposed to different trace elements and the changes were not specific to the treatment used (lichen bag exposition, in field and in vitro treatments). The in vitro treatment gave the highest frequency of damage at all time points. X-ray TEM microanalysis revealed trace elements inside the cell walls and the cytoplasmic vesicles of the lichens cultured with the trace elements; this localization is probably related to tolerance mechanisms.

RECONSTRUCTION OF PAST CO2 CONCENTRATION AT A NATURAL CO2 VENT SITE USING RADIOCARBON DATING OF TREE RINGS

Total CO2 exposure levels in a naturally enriched site (Lajatico, Italy) were reconstructed using radiocarbon analysis by accelerator mass spectrometry combined with dendrochronological analysis on wood cores extracted from trees grown in the fossil CO2 source proximity. Over 3 decades (1964-1998), the data show a mean CO2 concentration in the atmo- sphere of 650 ppm, about twice the current concentration in atmosphere, with a maximum around 1980.

New distributional data of the rare endemic species Eokochia saxicola (Guss.) Freitag and G. Kadereit (Chenopodiaceae): Effects on biogeography and conservation

Eokochia saxicola (Guss.) Freitag & G. Kadereit is a very rare endemic species of southern Italy and one of the rarest plants in Europe, included as priority species in the Annex II of the Council Directive 92/43/EEC. During the floristic surveys in the Cilento e Vallo di Diano National Park (Campania region, southern Italy), with the aim to assess the conservation status of rare and/or endemic species, new sites of occurrence of E. saxicola have been recorded representing the first known mainland sites; in fact, this endemic species was previously recorded only in the insular sites of Ischia (where it is extinct) and Capri in Campania region and Strombolicchio in Sicily region. Moreover, a further site was found in Capri island. So, three new sites of occurrence of E. saxicola have been recorded, increasing the total number from the two previously known to the actual five; in Campania, the total number increased from one to four. The research also increased significantly the global population size, currently made up of about 270 individuals compared with the 150 previously known. Consequences for the biogeography of the species and practical issues for conservation are discussed.

Are Red List really useful for plant conservation? The New Red List of the Italian Flora as a study case in the perspective of national conservation policies

“The New Red List of the Italian Flora” includes all the Italian policy species and other species of known conservation concerns for a total of 400 taxa, 65% of which are threatened with extinction. The Red List is based on a huge georeferenced data-set useful for conservation purposes.