Effectiveness of aerobiological dispersal and microenvironmental requirements together influence spatial colonization patterns of lichen species on the stone cultural heritage.

Dispersal patterns of lichen species in monumental and archaeological sites and their relationships with spatial population structure are almost unknown, hampering predictions on colonization dynamics that are fundamental for planning conservation strategies. In this work, we tested if the local abundance and distribution pattern of some common lichen species on carbonate stones of heritage sites may be related to their patterns of propagule dispersal. We combined analyses of the spatial population structure of eight species on the calcareous balustrade of a heritage site in Torino (NW Italy) with aerobiological analyses.

Morphological, Secondary Metabolite and ITS (rDNA) Variability within Usnic Acid-Containing Lichen Thalli of Xanthoparmelia Explored at the Local Scale of Rock Outcrop in W-Alps.

Lichen secondary metabolites (LSMs) are regarded with interest for valuable biological properties, but chemical variability among/within lichen taxa has been only fragmentarily characterized by advanced analytical techniques. Knowledge of variability at a local geographic scale has been particularly neglected, while it should address the collection of chemically homogeneous materials to test and exploit LSMs. Here we evaluated the chemical variability of 48 Xanthoparmelia specimens from two rock outcrops in Western Italian Alps, representative of nine morphotypes and sixteen rDNA ITS haplotypes.

Spores of lichen-forming fungi in the mycoaerosol and their relationships with climate factors.

Fungal particulates are a dominant component of the bioaerosol, but aerobiological studies traditionally focused on a limited set of fungi having relevance as allergens or plant pathogens. This study first analyzes the occurrence of lichen meiospores in the mycoaerosol, quantitatively evaluating in the atmosphere of an alpine environment the occurrence of polar diblastic spores, unequivocally attributable to the lichen family Teloschistaceae. The analysis of air-samples collected one week per month for one year with a Hirst-type sampler displayed a low percentage occurrence of polar-diblastic spores (<0.

In vitro receptivity of carbonate rocks to endolithic lichen-forming aposymbionts.

Sterile cultured isolates of lichen-forming aposymbionts have not yet been used to investigate lichen-rock interactions under controlled conditions. In this study mycobionts and photobiont of the endolithic lichens Bagliettoa baldensis and Bagliettoa marmorea were isolated and inoculated with coupons of one limestone and four marbles commonly employed in the Cultural Heritage framework. After one year of incubation, microscopic observations of polished cross-sections were performed to verify if the typical colonization patterns observed in the field may be reproduced in vitro and to evaluate the receptivity of the five lithotypes to endolithic lichens.

The effect of weathering on ecopersistence, reactivity, and potential toxicity of naturally occurring asbestos and asbestiform minerals.

The mechanisms underlying asbestos toxicity mainly rely on experiments performed on "laboratory" fibers, but little data is available on naturally occurring asbestos (NOA). Human exposure to NOA is subject to their ecopersistence and the modulation of their potential toxicity following weathering. The effect of weathering on three fibrous minerals from the Italian Western Alps, chrysotile, tremolite, and balangeroite-a Fe-rich asbestiform mineral-was investigated by mimicking more than 100 yr of physical (freezing-thawing/wetting-drying cycles in a climatic chamber) and biochemical forces (incubation with oxalic acid).