Luciana Zedda

Impacts of alien plants and man‐made disturbance on soil‐growing bryophyte and lichen diversity in coastal areas of Sardinia (Italy)

Abstract Seventy phytosociological relevés were performed in 1 m × 1 m plots at 14 study sites spread along sandy shores in northern and southern Sardinia (Italy). The plots were selected in different habitat types (open dunes, native Juniperus woodlands, maquis, and plantations with Acacia, Eucalyptus and Pinus) according to a stratified sampling method in order to investigate impacts deriving from different levels of Carpobrotus spp. cover, dry litter from exotic trees, and other disturbance types. The quantile regression and logistic regression analyses revealed that the reduction in the amount of bryophyte and lichen cover on sand dunes of the study area is caused either by a high cover of Carpobrotus spp. mats or by a high cover of dry exotic litter in dense, unmanaged or poorly managed forest plantations. Additional detrimental effects are often driven by other kinds of man‐made disturbances. Forest management in the coastal areas of Sardinia should be gradually modified to take into account the conservation of bryophytes and lichens. Some of the biological indicators used are quite widespread in the Mediterranean coastal habitats or are exclusively associated with sand dunes; therefore, they can also be conveniently used as indicators of biological impacts in other countries or islands of the same biogeographical region.

Diversity and ecology of terricolous bryophyte and lichen communities in coastal areas of Sardinia (Italy)

A first characterization of soil-growing bryophyte and lichen communities along the coasts of Sardinia (Italy) is presented. The lichen Micarea melaenida is reported for the first time. Altogether, 5 different communities are reported: Group 1, dominated by Tortella flavovirens, Cladonia convoluta and Pleurochaete squarrosa; Group 2, close to the Cladonietum mediterraneae; Group 3, with dominance of the bryophytes Tortella flavovirens, Rhynchostegium megapolitanum and Bryum capillare; and Group 4, characterized as a Tortella flavovirens fragment community. In many plots neither bryophytes nor lichens were recorded (Group 5). Bryophytes and lichens present different ecological requirements. The bryophytes are more tolerant of shaded conditions, eutrophication and higher soil pH, whereas lichens are more sensitive to man-made disturbance, especially trampling, fire and competition from exotic species. The highest diversity of both groups of organisms (lichens and bryophytes) is found in well-preserved native Juniperus woodlands, while no bryophytes or lichens are present in highly disturbed areas. Both are severely threatened by human activities and plant invasion, and require special protection through the forest management policies outlined here: thinning of exotic vegetation, removal of exotic species, and increased propagation of natural vegetation.

The Diversity of Lichenised Fungi: Ecosystem Functions and Ecosystem Services

Biodiversity supports ecosystem functioning and productivity, and makes ecosystems more resilient and resistant to changes. Ecosystem functions are due to the biological, geochemical and physical processes occurring within an ecosystem. They relate to the structural components (e.g. water, soil, atmosphere, and biota) and their interactions within and across ecosystems. Functions that are useful to human well-being are defined as ‘ecosystem services’. Lichenised fungi are complex and form diverse ‘functional organismic communities’. They can be regarded as individuals as well as microhabitats comprising a huge variety of coexisting fungal, algal and bacterial taxa or genotypes, pertaining to most different domains of life. Lichens and their symbionts underpin a great number of ecosystem functions (i.e., rock decomposition, soil formation, carbon, and nitrogen fixation), support the diversity of numerous organisms, e.g. through the provision of food, habitat, shelter, camouflage, or nesting material. Furthermore, they provide numerous direct and indirect ecosystem services, which are presented in detail in this overview. Examples are the provision of lichen secondary metabolites and other compounds for medicinal and other purposes, the use of lichens as bioindicators of environmental changes, and as inspiration source in the context of culture, arts and design. The aim of the present review is to give insight in the current knowledge on ecosystem functions provided by lichens, as well as to point out which of these are, directly or indirectly, of benefit for human beings. Lichens are often neglected in ecosystem service analyses and nature conservation management, mostly due to underestimation of their role and difficulties in identification. The primary agents and lichen traits involved in ecosystem processes are analysed, and possible approaches on how to quantify, estimate the value, model and map lichen ecosystem services are discussed.

Diversity and ecology of soil lichens in the Knersvlakte (South Africa)

Abstract The lichen vegetation forming biological soil crusts is described for the first time for a semi-desert area of the Republic of South Africa (Knersvlakte, Namaqualand). Thirty-five terricolous lichen taxa were recorded. Fifty-two percent of the lichens are endemic to Namaqualand according to current knowledge. Squamulose and crustose lichens were the most common (over 60% of taxa) and most contained green algal photobionts. Three main communities were distinguished: 1) a widespread community composed by Collema coccophorum, Psora aff. crenata, Placidium tenellum and P. squamulosum; 2) a rare community characterized by foliose lichens belonging to Xanthoparmelia, Neofuscelia and Paraparmelia; and 3) a rare, crustose community formed by Caloplaca sp. (“C. sp. 1”), Toninia sp. (“T. sp. 1”), T. ruginosa and Buellia sp. (“B. sp. 2”). The lichen taxa and vegetation of the study area are unique and are threatened by land management practices and changing climate.

The lichen genera Lepraria and Leproloma in Sardinia (Italy)

Abstract The lichen genera Lepraria Ach. and Leproloma Nyl. ex Cromb. in Sardinia (Italy) have been reviewed with particular reference to corticolous species. 10 species of Lepraria and 3 of Leproloma are reported. 4 species are added to the lichen flora of the island (Lepraria caesioalba (de Lesd.) J. R. Laundon, L. jackii Tonsberg, L. sp. and Leproloma vouauxii (Hue) J. R. Laundon). A new chemotype, morphologically identical to L. nivalis J. R. Laundon is described (with roccellic acid and atranorin). Morphological, chemical and ecological information on each species are presented, together with a key for the identification. This is the first treatment for the Mediterranean area.

Lichen diversity on dolmen and menhir in the Megalithic complex of Sa Coveccada (Mores, Sardinia)

This work describes the lichen diversity found on the megalithic Dolmen of Sa Coveccada (Mores, Sardinia) until 2010. After that year, a restoration with chemical removal of lichen crusts took place, which destroyed a great part of the lichen communities. These were studied again after removal and lichen communities occurring on rock outcrops in the surroundings of the Dolmen and on a contiguous menhir were investigated as well for comparison. Before the restoration, 33 species had been recorded on the Dolmen, most being crustose, followed by foliose and fruticose forms. Among these, eight species are regarded as rare in Sardinia and five rare at lower elevations. Most of the recorded species are typical for eutrophic substrates and for meso- to xerophytic conditions. Studies on lichen diversity on archaeological monuments in Sardinia are limited. This is the first report on the lichens of a Sardinian dolmen. This paper questions whether the lichen diversity of such monuments should be preserved as lichens have been an important part of the monument ecosystem and of the landscape for many centuries. This work also aims to improve collaboration among lichen and monument experts, in order to avoid hasty restoration decisions.

Geographic heat maps of lichen traits derived by combining LIAS light description and GBIF occurrence data, provided on a new platform

LIAS gtm, a new platform of the LIAS lichen information system, is presented. It allows for the visualization of phenotypic traits via geographic heatmapping of relative trait frequencies (RTFs) based on data derived from GBIF (occurrence data) and from LIAS light (taxon description data). The data are combined and referred to defined geographic areas of interest. Exemplarily, LIAS gtm provides distribution patterns of a selection of single, dual or multiple traits. The data are visualized for two lichen record hotspots, Scandinavia and Australia. Detailed technical information is provided on the platform web site itself.