Fraxinus excelsior L. (ash) is a key forest tree species challenged by Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya, the causal agent of ash dieback. The goals of this study were (I) ...to assess the presence, spatial distribution, and incidence of H. fraxineus in the inner-alpine valleys of northwestern Italy, along with the severity of ash dieback; (II) to model the probability of infection by H. fraxineus based on environmental variables; (III) to reconstruct the direction of provenance of the front of invasion of the pathogen; and (IV) to test whether H. fraxineus has replaced the native relative Hymenoscyphus albidus (Gillet) W. Phillips, a saprobe of ash litter. By combining phytosanitary monitoring and samplings in 20 forest stands, laboratory analyses, and statistical modelling, this study showed that H. fraxineus was present in 65% of stands with an average incidence of 27%, reaching peaks of 80%. Rainfalls were the most relevant drivers of the probability of infection by H. fraxineus, rising up to 80% with the increased precipitation in April and July. Other drivers included elevation, maximal temperatures, latitude, and longitude. The front of invasion likely moved from Italy and/or Switzerland, rather than from France, while the replacement of H. albidus is uncertain.
In the western sector of the Alps, and particularly in the Aosta Valley, lichenological communities on broad-leaved trees have received very little attention, and information about lichen species ...associated with common ash (Fraxinus excelsior L.) are still scanty. Therefore, in this study, we analyzed epiphytic lichen communities of ash trees to estimate their composition, their conservation value, and their association with some key environmental variables. Our results show that lichen communities appear to be different in terms of occurrence and frequencies in different sampling sites. The tested environmental variables contribute to shape the lichen communities, which are significantly different (p < 0.05) in sites characterized by different elevation, solar radiation, and source vicinity. The conservation value of lichen species was assessed by comparing distributional data at the national and local level. Our findings show that, in the Italian Alps, ash trees represent an important substrate for locally, or even nationally, rare lichens: 14 recorded species were not previously known in the study area, and some (Lecanora impudens and Rinodina polyspora) were included in the red list of Italian epiphytic lichens.
•Up to 11% of the bioaerosol particles are fungal spores and mycelium fragments.•There is a need to assess the spatio-temporal patterns of fungal diversity.•eDNA metabarcoding complements traditional ...morphological analyses.•eDNA have high detection efficiency, though strong taxon-dependency is reported.•Both methods should be complementary used to assess airborne fungal diversity.
Fungi represent relevant allergens and plant pathogens that can disperse on long ranges, potentially producing severe consequences on public health and agriculture. Up to 11% of the bioaerosol particles are fungal spores and mycelium fragments. Estimation of fungal species diversity in time and space is decisive but may be biased by abiotic conditions and sampling methods. Traditional morphological analyses of fungal spores have been widely applied in aerobiology in the past, while recently eDNA metabarcoding can complement these studies. Here, we used both morphological analysis (spore count and taxon identification) and high-throughput sequencing to disentangle spatio-temporal variation of fungi across Northern and Central Italy and to evaluate the detection efficiency of the two approaches. Our results showed that eDNA metabarcoding detects about three times more genera and has a higher detection efficiency than the morphological analyses. However, the efficiency is high in both spore count and eDNA metabarcoding methods when the most abundant or the rarest genera are considered but it can substantially vary between the two approaches when moderately abundant genera are analyzed. Furthermore, morphological spore determination resulted in higher variance explained by PERMANOVA analysis with respect to eDNA metabarcoding (26% and 13%, respectively), which leads to a better spatio-temporal characterization of the fungal genera. As both morphological analyses and eDNA metabarcoding methods capture significant interactions between seasons and sites, they could be preferably used as complementing approaches to reliably study airborne fungal diversity and variation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Heterobasidion annosum species complex includes major fungal pathogens of conifers worldwide. State-of-the-art preventative stump treatments with urea or with commercial formulations of the ...fungal biological control agent Phlebiopsis gigantea (i.e., Rotstop®) may become no longer available or are not approved for use in many areas of Europe infested by the three native Heterobasidion species and by the North American invasive H. irregulare, making the development of new treatments timely. The efficacy of Proradix® (based on Pseudomonas protegens strain DSMZ 13134), the cell-free filtrate (CFF) of the same bacterium, a strain of P. gigantea (MUT 6212) collected in the invasion area of H. irregulare in Italy, Rotstop®, and urea was comparatively investigated on a total of 542 stumps of Abies alba, Picea abies, Pinus pinea, and P. sylvestris in forest stands infested by the host-associated Heterobasidion species. Additionally, 139 logs of P. pinea were also treated. Results support the good performances of Rotstop®, and especially of urea against the native Heterobasidion species on stumps of their preferential hosts and, for the first time, towards the invasive North American H. irregulare on stumps of P. pinea. In some experiments, the effectiveness of Proradix® and of the strain of P. gigantea was weak, whereas the CFF of P. protegens strain DSMZ 13134 performed as a valid alternative to urea and Rotstop®. The mechanism of action of this treatment hinges on antibiosis; therefore, further improvements could be possible by identifying the active molecules and/or by optimizing their production. Generally, the performance of the tested treatments is not correlated with the stump size.
Similarly to other Mediterranean regions, Italy is expected to experience dramatic climatic changes in the coming decades. Do to their poikilohydric nature, lichens are among the most sensitive ...organisms to climate change and species requiring temperate-humid conditions may rapidly decline in Italy, such in the case of the epiphytic Lobaria species that are confined to humid forests. Our study, based on ecological niche modelling of occurrence data of three Lobaria species, revealed that in the next decades climate change will impact their distribution range across Italy, predicting a steep gradient of increasing range loss across time slices. Lobaria species are therefore facing a high extinction risk associated with reduction of their range. The current patterns indicate that only L. pulmonaria still has a continuous distribution across Italy, with potential contact between Apennine and Alpine populations. This situation is consistent with the wider climatic niche of this species, still offering a major opportunity for its successful long-term conservation. Results (a) support the inclusion of the three Lobaria species in European conservation policies, such as the Habitat Directive, and (b) warn against an over-estimation of the indicator power of single flagship species to establish conservation priorities for lichens, indicating that even lichens with peculiar and similar climatic envelopes may fail to co-occur within a given forest stand. A multiple indicator approach could provide more useful tools for a community-based conservation strategy for epiphytes.
•Lichens are among the most sensitive organisms to climate change.•Climate change will impact the distribution range of Lobaria species across Italy.•Lobaria species are facing extinction risk due to range reduction.•Lobaria species should be included in European conservation policies.•A multiple indicator approach could support conservation priorities for lichens.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In this contribution, new data concerning algae, bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genera Chara and Nitella , ...the bryophyte genera Brachythecium , Didymodon , Fissidens , Physcomitrium , and Riccia , the fungal genera Biatoropsis , Cantharellus , Coprinellus , Dacrymyces , Inosperma , Nigropuncta , Urocystis , and Xanthoriicola , and the lichen genera Arthonia , Bellemerea , Circinaria , Lecania , Lecanora , Lecidella , Mycobilimbia , Naetrocymbe , Parmelia , Peltigera , Porpidia , Scytinium , and Usnea .
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this contribution, new data concerning Algae, bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genus
Nitella
, for the ...bryophyte genera
Anthoceros
,
Dicranodontium
,
Fontinalis
, and
Riccia
, the fungal genera
Inocybe
and
Xerophorus
, and the lichen genera
Bagliettoa
,
Biatora
,
Calicium
,
Cladonia
,
Coniocarpon
,
Lecanora
,
Opegrapha
,
Placynthium
,
Rhizocarpon
,
Scytinium
,
Solenopsora
,
Stereocaulon
, and
Verrucaria
.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this contribution, new data concerning bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera
Diplophyllum
and
...Ptychostomum
, the fungal genera
Arrhenia
,
Gymnosporangium
, and
Sporidesmium
and the lichen genera
Arthonia
,
Coenogonium
,
Flavoplaca
,
Gyalolechia
,
Parmotrema
,
Peltigera
,
Pterygiopsis
,
Squamarina
,
Tornabea
, and
Waynea
.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fraxinus excelsior L. (ash) is a key forest tree species challenged by Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya, the causal agent of ash dieback. The goals of this study were (I) ...to assess the presence, spatial distribution, and incidence of H. fraxineus in the inner-alpine valleys of northwestern Italy, along with the severity of ash dieback; (II) to model the probability of infection by H. fraxineus based on environmental variables; (III) to reconstruct the direction of provenance of the front of invasion of the pathogen; and (IV) to test whether H. fraxineus has replaced the native relative Hymenoscyphus albidus (Gillet) W. Phillips, a saprobe of ash litter. By combining phytosanitary monitoring and samplings in 20 forest stands, laboratory analyses, and statistical modelling, this study showed that H. fraxineus was present in 65% of stands with an average incidence of 27%, reaching peaks of 80%. Rainfalls were the most relevant drivers of the probability of infection by H. fraxineus, rising up to 80% with the increased precipitation in April and July. Other drivers included elevation, maximal temperatures, latitude, and longitude. The front of invasion likely moved from Italy and/or Switzerland, rather than from France, while the replacement of H. albidus is uncertain.
Environmental DNA (eDNA) metabarcoding and metagenomics analyses can improve taxonomic resolution in biodiversity studies. Only recently, these techniques have been applied in aerobiology, to target ...bacteria, fungi and plants in airborne samples. Here, we present a nine-month aerobiological study applying eDNA metabarcoding in which we analyzed simultaneously airborne diversity and variation of fungi and plants across five locations in North and Central Italy. We correlated species composition with the ecological characteristics of the sites and the seasons. The most abundant taxa among all sites and seasons were the fungal genera Cladosporium, Alternaria, and Epicoccum and the plant genera Brassica, Corylus, Cupressus and Linum, the latter being much more variable among sites. PERMANOVA and indicator species analyses showed that the plant diversity from air samples is significantly correlated with seasons, while that of fungi varied according to the interaction between seasons and sites. The results consolidate the performance of a new eDNA metabarcoding pipeline for the simultaneous amplification and analysis of airborne plant and fungal particles. They also highlight the promising complementarity of this approach with more traditional biomonitoring frameworks and routine reports of air quality provided by environmental agencies.
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•Airborne biodiversity is poorly known: its assesment is key to detect invasive (alien) and pathogen species aerodispersed.•Plant and fungal airborne diversity was investigated using eDNA metabarcoding.•A nine-month sampling in five localities and ad hoc primer amplification approach were implemented.•Plant diversity significantly correlates with seasons, fungal diversity varied according to seasons-localities interaction.•eDNA metabarcoding is a promising, complementing approach to traditional biomonitoring frameworks.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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