1,721,069 research outputs found
Human disturbance threats the red-listed macrolichen Seirophora villosa (Ach.) Frödén in coastal Juniperus-habitats: evidence from western peninsular Italy.
No full textIn Europe, coastal dune systems with Juniperus spp. (Natura 2000 habitat code 2250) are a priority habitat for conservation according to the Natura 2000 policies. Currently, anthropogenic pressure is threatening the biodiversity of this habitat. While the impact of human pressure on animals and vascular plants is already documented, information is still scanty for other organisms such as epiphytic lichens. The main aim of this study is to test the effect of human disturbance on the occurrence and abundance of the red-listed macrolichen Seirophora villosa. We also tested the effect of human disturbance on the whole community of epiphytic lichens in terms of species richness and composition. The study was performed along the coast of Tuscany by comparing both disturbed and undisturbed Juniperus stands according to a stratified random sampling design. Our results provided evidence that in coastal systems the long-term conservation of the red-listed macrolichen S. villosa and its characteristic community composed by several Mediterranean species of conservation concern depends on the maintenance of undisturbed Juniperus habitats. Results also support the possibility of using S. villosa as an indicator species of habitat conservation importance and habitat integrity since its occurrence is predicted on nestedness in term of species composition, assemblages of species poor disturbed stands being subsets of those of richer undisturbed stand
Biological effects of ammonia released from a composting plant assessed with lichens
Full text linkIn this study, we investigated whether ammonia emissions from industrial composting of organic waste may influence the surrounding environment, using lichens as bioindicators. To this purpose, samples of N-tolerant and N-sensitive lichens, namely Xanthoria parietina and Evernia prunastri, were transplanted for 1-3 months along transects at increasing distance (0-400 m) from a composting facility in Tuscany, Italy. Atmospheric concentrations of ammonia were measured using passive samplers. The physiological response of lichen transplants was investigated by means of the photosynthetic efficiency (measured as chlorophyll a fluorescence emission), the integrity of cell membranes (measured as electrolyte leakage), and sample viability (measured as enzymatic activity of dehydrogenase). Epiphytic lichen communities were investigated using biodiversity indices. The results showed decreasing concentrations of ammonia, from 48.7 mu g/m(3) at the composting facility to 2.7 mu g/m(3) at 400 m. The N-tolerant X. parietina was not affected and some physiological parameters even showed a higher performance, while the N-sensitive E. prunastri showed a reduced performance with increasing atmospheric concentrations approaching the source. A shift from lichen communities composed by meso-acidophilous species (actual condition) to more nitrophilous communities in the near future, approaching the composting facility is suggested. It is concluded that lichens can provide useful data for decision-makers to establish correct science-based environmentally sustainable waste management policies
Modelling range dynamics of terricolous lichens of the genus Peltigera in the Alps under a climate change scenario
No full textClimate change is expected to strongly impact biodiversity in Alpine ecosystems and species distribution modelling is increasingly used to provide anticipatory information to guide conservation. In this study, (1) we quantified the range loss, range gain, range change and range turnover caused by climate change in the genus Peltigera a group of terricolous lichens widespread across the Alps, and then (2) we evaluated the relationships between the predictors of range dynamics and functional traits. Our results indicate moderate range dynamics for species of the genus Peltigera across the Alps under a climate change scenario. This would imply a relative stability and resistance of these lichens to climate change that may reflect the local persistence of the species under sub-optimal conditions. Our results also suggest that range dynamics could be associated with functional traits mainly related to water-use strategies and to a trade-off between dispersal and establishment ability. This finding suggests that functional traits may strongly modulate the lichen response to climate change and that species with similar functional traits are prone to similar selective pressures
Functional over-redundancy and vulnerability of lichen communities decouple across spatial scales and environmental severity
No full textAccording to the insurance hypothesis, high taxonomic diversity should ensure ecosystem stability because of functional redundancy, whereas reduced functional diversity that results from species loss should affect ecosystem sensitivity, resilience, and vulnerability. However, even in species-rich ecosystems, functional over-redundancy (FOR; i.e., the tendency of most species to cluster into a few over-represented functional entities) in some cases may result in under-representation of many functions, and the ecosystem might become highly vulnerable. Using a stratified random sampling design with nested spatial levels (nine land use strata, 70 plots, 435 trees/rock outcrops, and 9845 quadrats), we recorded the occurrence of over 350 species of epiphytic and rock-dwelling lichens in semi-arid ecosystems in western Sardinia, where solar radiation defines a wide environmental gradient. By accounting for species functional traits, such as growth form, photosynthetic strategies, and reproductive strategies, we obtained 43 functional entities (>60% of all possible combinations) and tested the scale-dependency of FOR and functional vulnerability (FV, i.e., the risk of losing functional entities) by generalized linear mixed models. We found that FOR increased and FV decreased with increasing spatial scale, which supports the hypothesis of a cross-scale functional reinforcement. Decoupling of FOR and FV was far more evident for rock-dwelling compared with epiphytic communities, which reflects differing environmental conditions associated with substrate type. Our results indicate that increased warming and climatic extremes could exacerbate species clustering into the most resistant functional entities and thus enhance FOR at the community level. Therefore, high taxonomic diversity may not ensure systematic buffering of climate change impacts
Range shifts of native and invasive trees exacerbate the impact of climate change on epiphyte distribution: The case of lung lichen and black locust in Italy
Full text linkWhile changing climatic conditions may directly impact species distribution ranges, indirect effects related to altered biotic interactions may exacerbate range shifts. This situation fully applies to epiphytic lichens that are sensitive to climatic factors and strongly depend on substrate occurrence and features for their dispersal and establishment. In this work, we modelled the climatic suitability across Italy under current and future climate of the forest species Lobaria pulmonaria, the lung lichen. Comparatively, we modelled the suitability of its main tree species in Italy, as well as that of the alien tree Robinia pseudoacacia, black locust, whose spread may cause the decline of many forest lichen species. Our results support the view that climate change may cause range shifts of epiphytes by altering the spatial pattern of their climatic suitability (direct effect) and simultaneously causing range shifts of their host-tree species (indirect effect). This phenomenon seems to be emphasized by the invasion of alien trees, as in the case of black locust, that may replace native host tree species. Results indicate that a reduction of the habitat suitability of the lung lichen across Italy should be expected in the face of climate change and that this is coupled with a loss of suitable substrate. This situation seems to be determined by two main processes that act simultaneously: 1) a partial reduction of the spatial overlap between the climatic niche of the lung lichen and that of its host tree species, and 2) the invasion of native woods by black locust. The case of lung lichen and black locust in Italy highlights that epiphytes are prone to both direct and indirect effects of climate change. The invasion of alien trees may have consequences that are still poorly evaluated for epiphytes
Additions to the lichen flora of the Ligurian Apennines (NW Italy)
No full textThis paper reports 24 lichens from the Ligurian Apennines, 11 of which are new to Liguria and 4 to Emilia regions in N-Italy
Diversità funzionale delle comunità licheniche epifite di ginepreti dunali: quanto conta la struttura dell’habitat?
No full textNew records for lichen regional floras of Italy
No full textThirty-five lichen species, collected during several trips in Italy are listed. These records are additions to the lichen flora of Liguria (21 species), Toscana (5), Sicilia (1), Abruzzo (1), Lazio (1), Sardegna (1); one species is new to N Italy and 2 to C Italy. Additional information is given for some other rare species, while the occurrence of some taxa previously reported only from collections dating back to the XIX century is confirmed
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