Dynamics and ecological functions of Cryptogam Soil Crusts (CSC) in planitial landscapes of continental-temperate regions

Dry grasslands and heathlands are important habitats for biodiversity conservation and host cryptogam soil crusts (CSC) that greatly contribute to ecosystem functioning. This thesis aims at exploring: the terricolous lichen diversity in dry habitats in a human-impacted lowland (Po Plain, N Italy); the compositional patterns of CSC across dry grasslands and heathlands, also accounting for the dynamic stage of the vegetation (pioneer vs mature); the effects of small-scale disturbances on the three main taxa found in cryptogam-rich dry grasslands (vascular plants, lichens, bryophytes); the potential of CSC in delivering the ecosystem service of storing seeds of vascular plants, in the perspective of habitat restoration. Diversity and dynamics were studied by means of vegetation surveys in circular plots, whose number was area-dependent, located along transects in each habitat patch (= 185 plots in 60 grasslands, 114 plots in 22 heathlands). The % cover of each plant, bryophyte and lichen was recorded, with environmental (soil pH and texture, vegetation structure, altitude, bare soil %), disturbance-related (human trampling, cattle and lagomorphs fecal pellets, wild boar scratches) and climate variables (mean annual temperature and precipitation). The composition in lichens and bryophytes was compared among the 3 habitat types (3 groups) and between their dynamic stages (pioneer vs mature, 6 groups) to understand whether it is habitat- and stage-specific by means of NMDS, PERMANOVA and Indicator Species Analysis. Drivers of cover and species richness of the 3 taxa were analyzed for dry grasslands by means of generalized linear models. The seed storing function was studied taking 5 samples of CSC in 4 acidic grassland patches (= 20 samples), each sample taken at the centre of one plot surveyed in the previous spring. The samples were dryed, crumbled on sterile gardening soil in a controlled situation. All the germinated seedlings were identified and counted. Data were analyzed in comparison to data from the donor plots by means of Kruskal-Wallis test and linear regression, considering all the species and then native and non-native species separately . 33 terricolous lichen species were recorded, of which 13 of conservation concern. In spite of the widespread presence of few common species and the generally low species richness, composition differs significantly between the 3 habitat types and between pioneer vs mature heathlands, less markedly between dynamic stages within each grassland type. Three well-characterized assemblages which include many species of conservation concern were found for both lichens and bryophytes. Cryptogam assemblages are influences also by rainfall, soil features and vegetation structure. Increase of soil pH and disturbance by lagomorph fecal pellets have a negative effect on lichens, as well as their interaction (the negative effect of pellets is more evident at the increase of soil pH). Soil pH, fecal pellets and precipitation have a positive effect on bryophytes. Human trampling and fecal pellets have a negative effect on vascular plants, while increase of soil pH has a positive effect. The interaction of soil pH and pellets has an effect opposite than on lichens (the negative effect of pellets is more evident at the decrease of soil pH). CSC are able to store and release vascular plant seeds which are viable and can germinate when placed in proper conditions. The number of species and individuals of vascular plants germinated from CSC is comparable to what recorded in nature in the donor plots. Native species richness was higher, while native species germinated with less individuals than non-native species. These results are useful in addressing conservation towards the management and protection of all the lowland dry habitats, due to the differentiation among the cryptogam assemblages they host and to the presence of several species of conservation concern.Dry grasslands and heathlands are important habitats for biodiversity conservation and host cryptogam soil crusts (CSC) that greatly contribute to ecosystem functioning. This thesis aims at exploring: the terricolous lichen diversity in dry habitats in a human-impacted lowland (Po Plain, N Italy); the compositional patterns of CSC across dry grasslands and heathlands, also accounting for the dynamic stage of the vegetation (pioneer vs mature); the effects of small-scale disturbances on the three main taxa found in cryptogam-rich dry grasslands (vascular plants, lichens, bryophytes); the potential of CSC in delivering the ecosystem service of storing seeds of vascular plants, in the perspective of habitat restoration. Diversity and dynamics were studied by means of vegetation surveys in circular plots, whose number was area-dependent, located along transects in each habitat patch (= 185 plots in 60 grasslands, 114 plots in 22 heathlands). The % cover of each plant, bryophyte and lichen was recorded, with environmental (soil pH and texture, vegetation structure, altitude, bare soil %), disturbance-related (human trampling, cattle and lagomorphs fecal pellets, wild boar scratches) and climate variables (mean annual temperature and precipitation). The composition in lichens and bryophytes was compared among the 3 habitat types (3 groups) and between their dynamic stages (pioneer vs mature, 6 groups) to understand whether it is habitat- and stage-specific by means of NMDS, PERMANOVA and Indicator Species Analysis. Drivers of cover and species richness of the 3 taxa were analyzed for dry grasslands by means of generalized linear models. The seed storing function was studied taking 5 samples of CSC in 4 acidic grassland patches (= 20 samples), each sample taken at the centre of one plot surveyed in the previous spring. The samples were dryed, crumbled on sterile gardening soil in a controlled situation. All the germinated seedlings were identified and counted. Data were analyzed in comparison to data from the donor plots by means of Kruskal-Wallis test and linear regression, considering all the species and then native and non-native species separately . 33 terricolous lichen species were recorded, of which 13 of conservation concern. In spite of the widespread presence of few common species and the generally low species richness, composition differs significantly between the 3 habitat types and between pioneer vs mature heathlands, less markedly between dynamic stages within each grassland type. Three well-characterized assemblages which include many species of conservation concern were found for both lichens and bryophytes. Cryptogam assemblages are influences also by rainfall, soil features and vegetation structure. Increase of soil pH and disturbance by lagomorph fecal pellets have a negative effect on lichens, as well as their interaction (the negative effect of pellets is more evident at the increase of soil pH). Soil pH, fecal pellets and precipitation have a positive effect on bryophytes. Human trampling and fecal pellets have a negative effect on vascular plants, while increase of soil pH has a positive effect. The interaction of soil pH and pellets has an effect opposite than on lichens (the negative effect of pellets is more evident at the decrease of soil pH). CSC are able to store and release vascular plant seeds which are viable and can germinate when placed in proper conditions. The number of species and individuals of vascular plants germinated from CSC is comparable to what recorded in nature in the donor plots. Native species richness was higher, while native species germinated with less individuals than non-native species. These results are useful in addressing conservation towards the management and protection of all the lowland dry habitats, due to the differentiation among the cryptogam assemblages they host and to the presence of several species of conservation concern

Refining the picture: new records to the lichen biota of Italy

Based on the analysis of both historical and recent collections, this paper reports an annotated list of taxa which are new to the lichen biota of Italy or of its administrative regions. Specimens were identified using a dissecting and a compound microscope; routine chemical spot tests and standardized thin-layer chromatography (TLC or HPTLC). The list includes 225 records of 153 taxa. Twenty taxa are new to Italy, the others are new to one or more administrative regions, with 15 second records and 5 third records for Italy. Some of the species belong to recently-described taxa, others are poorly known, sterile or ephemeral lichens which were largely overlooked in Italy. Several species are actually rare, either because of the rarity of their habitats (e.g. old-growth forests), or because in Italy they are at the margins of their bioclimatic distribution. The picture of the lichen biota of Italy has now new pixels, but its grain is still coarse. Further analysis of historical collections, increased efforts in the exploration of some areas, and the taxonomic revision of critical groups are still necessary to provide more complete distributional data for new biogeographic hypotheses, taxonomic and ecological research, and biodiversity conservation

Morphological and Chemical Traits of Cladonia Respond to Multiple Environmental Factors in Acidic Dry Grasslands

Terricolous lichen communities in lowlands occur especially in open dry habitats. Such communities are often dominated by species of the genus Cladonia, which are very variable in morphology, reproduction strategies, and secondary metabolites. In this work, we investigated traits-environment relationships considering vegetation dynamics, substrate pH, disturbance, and climate. A total of 122 plots were surveyed in 41 acidic dry grasslands in the western Po Plain (Northern Italy). Relationships between Cladonia traits and environmental variables were investigated by means of a model-based Fourth Corner Analysis. Thallus morphology and metabolites responded to vegetation dynamics, substrate pH, disturbance, and climate, whereas reproduction strategies responded only to vegetation dynamics. Traits\u2019 correlations with vegetation dynamics elucidate their colonization patterns in open dry habitats or suggest biotic interactions with bryo-phytes and vascular plants. In addition, correlations between metabolites and environmental factors support interpretations of their ecological roles. Our results also stress the importance of studying traits\u2019 relationships with climatic factors as an alert towards lichen reactions to climate change

A hotspot of lichen diversity and lichenological research in the Alps: the Paneveggio-Pale di San Martino Natural Park (Italy)

A checklist of 916 lichenised taxa is reported from the Paneveggio-Pale di San Martino Natural Park and its surroundings (Trentino-Alto Adige, N Italy), based on 7351 records from: (a) 72 literature sources, (b) eight public and private herbaria and (c) field observations by some of the authors. The study area appears as a hotspot of lichen diversity, hosting 30.1% of the lichen biota of the Alps in a territory that has 0.064% of their total surface area. This is mainly due to its high climatical, geological and orographic heterogeneity, but also to the long history of lichenological exploration, that started in the 19th century with Ferdinand Arnold and is still ongoing. The present work highlights the importance of detailed species inventories to support knowledge of biodiversity patterns, taxonomy and ecology and to properly address conservation issues. Fuscidea mollis var. caesioalbescens, Hydropunctaria scabra, Protoparmelia badia var. cinereobadia and Variospora paulii are new to Italy, 18 other taxa are new to Trentino-Alto Adige

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 2

In this contribution, new data concerning red algae, lichens and bryophytes of the Italian flora are presented. It includes new records and confirmations for the algal genus Grateloupia, the bryophyte genus Didymodon, and the lichen genera Buellia, Cladonia, Letharia, Pertusaria, and Pyrenula

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 3

In this contribution, new data concerning bryophytes, fungi and lichens and of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera Dicranodontium, Fontinalis, Lophocoleaand Riccia, the fungal genus Diplolaeviopsis, the lichen genera Agonimia, Cladonia, Protoparmelia, Rhizocarpon, and Scytinium

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 12

In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records, confirmations or exclusions for the bryophyte genera Acaulon, Campylopus, Entosthodon, Homomallium, Pseudohygrohypnum, and Thuidium, the fungal genera Entoloma, Cortinarius, Mycenella, Oxyporus, and Psathyrella and the lichen genera Anaptychia, Athallia, Baeomyces, Bagliettoa, Calicium, Nephroma, Pectenia, Phaeophyscia, Polyblastia, Protoparmeliopsis, Pyrenula, Ramalina, and Sanguineodiscus

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 4

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 Campylopus, Paludella, Tortula, and Conocephalum, the fungal genera Agonimia, Buelliella, Entorrhiza, Filicupula, Poronia, and Sporisorium, the lichen genera Cladonia, Dibaeis, Lasallia, and Rhizocarpon