1,720,986 research outputs found
Alla scoperta della biodiversità con nuovi strumenti interattivi: il progetto KeyToNature
No full textVICTORIA: an on-line information system on the lichens of Victoria Land (Continental Antarctica)
No full textVICTORIA is an on-line information system on the lichens of Victoria Land (Continental Antarctica). It provides descriptions and pictures of taxa, as well as nomenclatural, taxonomic, distributional and ecological data. Moreover, VICTORIA offers two interactive identification tools, dichotomous and multi-criteria keys, to the species. Friendly interfaces, optimized hierarchy of characters and multi-criteria filters based on easy-to-observe characters facilitate the identification process. At present VICTORIA provides information on 57 species occurring in the Terra Nova Bay area
Lichens as bioindicators in freshwater ecosystems – challenges and perspectives.
No full textThis paper summarizes information on freshwater lichens in relation with their potential for bioindication, mainly pointing to
ecological concepts and issues of practical relevance for promoting their inclusion in routine biomonitoring practices, thus contributing to a full
implementation of the eu Water framework directive. Results highlight the sensitiveness of freshwater lichens to some factors which cannot be
technically measured by singular visits, and have relevance for human planning purposes and environmental impact and risk assessment. however,
a full inclusion of freshwater lichens in monitoring practices would benefit from further ecological research testing the influence of potentially
meaningful ecological drivers and developing statistically robust sampling methods. This would allow the development of standard guidelines
applicable across europe according to the policies of the eu Water framework directive. on the taxonomical side, further dNa-based revisions and
the creation of a european checklist of freshwater lichens should provide the basis for developing modern identification tools. finally, it is suggested
that the use of freshwater lichens in biomonitoring may be improved by model studies based on comparative trials of full, quantitative, species
inventories at different spatial scales and by parallel simplified approaches with selected indicator species and morphological groups
Habitat types and lichen conservation in the Alps – Perspectives from a case study in the Stelvio National Park (Italy).
No full textAs a basis for promoting a lichen-oriented conservation strategy in alpine protected areas, this case study in the Stelvio National Park aims at comparing lichen communities of five habitats in terms of species richness and composition. Data are derived from an inventory in seven plots with five habitats each: (1) rural sites, (2) montane Picea abies-dominated forests, (3) subalpine Larix decidua/Pinus cembra-dominated forests, (4) small streams on siliceous bedrock, and (5) alpine mosaic of natural grasslands and siliceous rocks. In the analysis, three groups of species were considered: (1) all species, (2) species which in Italy are restricted to the Alps (referred to as "Alpic"), and (3) nationally rare species. A total of 428 species were found, including 79 Alpic and 59 nationally rare species. Substantial differences in the richness and composition of lichen species were found among the five habitats. In a conservation perspective, results indicated two main issues that should be considered: (1) each of the five habitat types contributes to lichen diversity by hosting different lichen assemblages and a pool of associated species and (2) forests managed by non-intensive practices and alpine mosaics should be prioritized in lichen conservation efforts, since they are the richest in Alpic and rare species
Influences of tree age and tree structure on the macrolichen Letharia vulpina: a case study in the Italian Alps
No full textTree age and tree structure are important determinants for epiphytic lichen communities, affecting substrate stability, light availability, and propagule dispersal. However, little is known about the relative importance of these 2 factors on many species. This work aims to evaluate the importance of tree age and tree structure in explaining the within-stand frequency of the macrolicheh Letharia vulpina. The study was carried out in 2 larch-stone pine forests in the Eastern Italian Alps. The frequency of Letharia was evaluated using a standard sampling method. To explain the within-stand frequency of Letharia, tree age and severil variables related to tree structure were considered. Multiple ordinary least square regression was applied to clarify the influence of the set of variables. Several partial regressions were then computed to evaluate the relative importance of each significant predictor. The frequency of Letharia increases with increasing tree age, tree diameter, and first branch height. Tree age is the most important variable, accounting for one third of the total explained variation, although tree structure also his a significant effect on lichen frequency. Due to its dispersal limitations and old-tree dependence Letharia is proposed as a suitable indicator of forest continuity. The results may be of interest for conservation purposes, since the frequency of Letharia may be enhanced by protecting old trees
Influence of tree age, tree size and crown structure on lichen communities in mature Alpine spruce forests
No full textTesting the relations between tree parameters and the richness and composition of lichen communities in near-natural stands could be a first step to gather information for forest managers interested in conservation and in biodiversity assessment and monitoring. This work aims at evaluating the influence of tree age and age-related parameters on tree-level richness and community composition of lichens on spruce in an Alpine forest. The lichen survey was carried out in four sites used for long-term monitoring. In each site, tree age, diameter at breast height, tree height, the first branch height, and crown projection area were measured for each tree. Trees were stratified into three age classes: (1) 200 years old, over-mature trees normally rare or absent in managed stands. In each site, seven trees in each age class were selected randomly. Tree age and related parameters proved to influence both tree-level species richness and composition of lichen communities. Species richness increased with tree age and related parameters indicative of tree size. This relation could be interpreted as the result of different joint effects of age per se and tree size with its area-effect. Species turnover is also suspected to improve species richness on over-mature trees. Similarly to species richness, tree-level species composition can be partially explained by tree-related parameters. Species composition changed from young to old trees, several lichens being associated with over-mature trees. This pool of species, including nationally rare lichens, represents a community which is probably poorly developed in managed forests. In accordance to the general aims of near-to-nature forestry, the presence of over-mature trees should be enhanced in the future forest landscape of the Alps especially in protected areas and Natura 2,000 sites, where conservation purposes are explicitly included in the management guidelines. © 2008 Springer Science+Business Media B.V
Epiphytic lichens in a riparian Natural Reserve of northern Italy: Species richness, composition and conservation
No full textIn Italy several natural reserves include riparian habitats, whose role in lichen conservation is still poorly known. This work aims at evaluating the importance for lichen conservation of a riparian natural reserve in NE Italy surrounded by a highly disturbed landscape, and at exploring the relations between lichen composition and different forest types. Epiphytic lichens were surveyed by a standard assessment protocol in: (1) alluvial Salix alba forests, (2) Alnus sp.pl. and Populus sp.pl. riparian forests, and (3) lowland Carpinus betulus and Quercus sp.pl. forests. One-way ANOVA was used to test differences between forest types. Species composition was explored by means of Redundancy Analysis. The overall lichen flora is relatively poor and rather homogeneous due to a group of disturbance-tolerant lichens, which are frequent in all forest types. This suggests a strong influence of the landscape context on species richness and composition, independently of the local habitat quality. However, the three forest types have rather different lichen floras, the least interesting for conservation being the riparian Alnus stands, while the alluvial Salix stands host a more sensitive flora and are worthy of lichen conservation. In spite of the disturbance and of its small extension, the reserve is still able to host several rare lichens. © 2008 Società Botanica Italiana
Freshwater lichens in springs of the eastern Italian Alps: floristics, ecology and potential for bioindication
No full textFreshwater habitats of the Italian Alps are largely unexplored and further floristic-ecological surveys are needed to clarify the
role of freshwater lichens in these environments. This applies especially to springs, since they seem to be suitable for a relatively
high number of aquatic species due to their ecological stability. The present work is focused on springs in an alpine region,
and is centered on: (a) floristics of freshwater lichens of the Italian Alps, (b) ecological and morphological information on potential
indicator species for calcareous and siliceous springs. The study was carried out in the eastern Italian Alps on 36 perennial
springs. Single springs proved to host a surprisingly low number of species, while at regional level the entire pool of investigated
springs host a relevant lichen flora representing 45% of the freshwater lichens of the Italian Alps. One species is new to Italy
and 3 are new to Trentino-Alto Adige. Biodiversity conservation measures should therefore be planned at regional level, including
a whole network of sites in different altitudinal belts and with different substrates. Verrucaria elaeomelaena and V. funckii
are the most frequent species on calcareous and siliceous springs respectively. They are suggested as potential indicator species,
since they proved to be indicative of the main physical, ecological and hydrochemical features of their habitat. A detailed morphological
description of these two species is also provided in order to enhance their identification by environmentalists
- …
