Soil contribution to the elemental composition of epiphytic lichens (Tuscany, central Italy)

Total concentrations of Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Sr, Ti, V and Zn in the epiphytic lichen Parmelia sulcata and superficial soils from 60 remote sampling sites in Tuscany (central Italy) were determined to evaluate the contribution of soil to the elemental composition of the lichen. The results showed that in the Mediterranean environment, the trace element content of unwashed lichen samples is greatly affected by soil contamination. However, despite the strong correlations between the concentrations of lithogene elements such as Al, Fe and Ti in P. sulcata, lichen levels of these elements were not at all linearly correlated with their concentrations in the soil, suggesting that dust contamination is highly variable and probably dependent on local site characteristics. All methods evaluated to minimize soil contamination indicated Cu, Pb and Zn as elements of atmospheric origin. However, while levels of Pb were similar to those reported for background areas, moderate pollution by Cu and Zn, probably from fertilizers used in agriculture, was revealed. For elements such as Cd and Mo, identified as atmophile, some uncertainty exists due to the fact that they are essential for lichen metabolism and accumulate intracellularly in lichens; they may therefore occur in soluble form in the lichen thallus

Analysis of the distribution of epiphytic lichens on Quercus pubescens along an altitudinal gradient in a Mediterranean area (Tuscany, central Italy)

The distribution of epiphytic lichens on Quercus pubescens in Tuscany, central Italy, was studied by means of multivariate techniques along an altitudinal gradient from 0 to 900 m. Great differences in community structure were found and the altitude of 500 m was identified as an ecotone. Epiphytic lichen vegetation on trees below the ecotone varied significantly in relation to bark pH. Climatic parameters (temperature and rainfall) were probably related to altitude. Dust was probably responsible for the rise in bark pH. The distribution of lichen species in the sampling belts fitted the core-satellite hypothesis. The use of core and satellite species as biomonitors of air pollution and bioindicators of environmental conditions is discussed

Accumulation of heavy metals in epiphytic lichens near a municipal solid waste incinerator (central Italy)

The epiphytic lichen Parmelia caperata was used as biomonitor in the area of a municipal solid waste incinerator (Poggibonsi, central Italy) to investigate the levels and the spatial distribution of the heavy metals Al, Cd, Cr, Cu, Fe, Hg, Pb and Zn. Levels of Al, Cu and Hg were similar to those in unpolluted areas, whereas high values were found for Cr, Zn and especially Cd. The distribution pattern of the last three metals and the exponential relationship of their concentrations with distance from the incinerator, showed that the disposal plant is a local source of atmospheric pollution due to Cd, Cr and Zn. For these metals, long-term hazard should be seriously taken into account

Temporal variation of air pollution in a geothermal area of central Italy: assessment by the biodiversity of epiphytic lichens

The results of a biomonitoring survey carried out in the geothermal area of Travale-Radicondoli (central Italy) are reported. The aim of the study was to evaluate the temporal variation of air pollution from 1992 to the present, based on the actual biodiversity of the epiphytic lichens compared with that of a previous study in the same area. Although instrumental measurements were not available, it was assumed that variations in the lichen biodiversity mostly reflected changes in the air pollution status. Furthermore, adopting a "before-after" strategy, the impact of a sansa oil extraction plant built in 1993 was also evaluated. The results showed that after 8 years, the geothermal area of Travale-Radicondoli is undergoing a gradual process of improvement, as clearly indicated by the colonization of some lichen species in areas previously affected by the "lichen desert". The surroundings of the geothermal power plants did not show evident changes from the previous study, as the biodiversity values remained low. The sansa oil extraction plant had a noticeable environmental impact that caused the air quality to worsen

A retrospective study using epiphytic lichens as biomonitors of air quality: 1980 and 1996 (Tuscany, central Italy)

The results of a retrospective study (data of 1980 and 1996) performed in the Chianti Region (Tuscany, central Italy) using epiphytic lichens both as sensitive indicators and accumulative monitors are presented. Floristic data, particularly the presence of numerous species known to be sensitive to air pollutants, indicated that air quality in the study area remained fairly good throughout this 16.year period, and may even have improved. Accumulation of trace elements in Parmelin cuperutu thalli collected in 1980 and 1996 supported this conclusion, with concentrations similar or even lower than those previously reported in other unpolluted areas of Tuscany. Most elements showed a marked decline from 1980 to 1996, suggesting that in the last years, the study area was subjected to a lower load of metal air pollution. Sulphur was the only element showing higher concentrations in 1996, probably due to the increased use of S-based pesticides in vineyard