Abstract The tailings dump of Barraxiutta (Sardinia, Italy) contains considerable concentrations of heavy metals and, consequently, is scarcely colonized by plants. However, wild populations of the ...liverwort Lunularia cruciata (L.) Dum. form dense and healthy‐looking carpets on this tailing dump. L. cruciata colonizing the tailing dump was compared with a control population growing in a pristine environment in terms of: (i) pollutant content, (ii) photochemical efficiency, and (iii) volatile secondary metabolites in thalli extracts. L. cruciata maintained optimal photosynthesis despite containing considerable amounts of soil pollutants in its thalli and had higher sesquiterpene content compared to control plants. Sesquiterpenes have a role in plant stress resistance and adaptation to adverse environments. In the present study, we propose enhanced sesquiterpenes featuring Contaminated L. cruciata as a defence strategy implemented in the post‐mining environment.
The lock and key hypothesis assumes that male and female genitalia match in a unique system to prevent interspecific crosses. This hypothesis is largely investigated in animals, while there is a ...distinct lack of studies on plants. Nevertheless, we expect the lock and key hypothesis could apply to plants with complex floral morphologies, such as orchids.
Here we apply a comparative approach to examine the variation of floral functional traits in food‐ and sex‐deceptive orchids. To understand if a specific deception strategy is related to a specific variation in floral traits evaluated the variation in sterile and fertile traits among species and subsequently examined the correlations between male and female reproductive organs of the same species with the aim of investigating the role of the lock and key hypothesis in deceptive orchids.
Our results show that the functional morphology of fertile traits plays a pivotal role in limiting gene flow in species that grow in sympatry. In particular, it was observed that the Reproductive Standardisation Index (RSI) is significantly different in the two pollination strategies and that the correlation between pollinarium length and stigmatic cavity length is stronger in food‐deceptive species when compared to the sex‐deceptive species.
These results reveal that the lock and key hypothesis contributes to maintain boundaries in plants with very complex floral morphology.
The occurrence on the Pollino massif (southern Italy) of several remarkable mosses, which are rare or very rare in Italy, is reported. They are Orthotrichum acuminatum H. Philib., Distichium ...inclinatum (Hedw.) Bruch & Schimp. and Grimmia longirostris Hook., new to the southern part of the Italian peninsula, and Schistidium dupretii (Thér.) W.A. Weber, new to South Italy. Moreover, Orthotrichum cupulatum Hoffm. ex Brid. var. fuscum (Venturi) Boulay, a very rare taxon in Europe and up to now considered vanished in Italy, is rediscovered in Italy after about one century from its single previous report.
The moss
Bryum radiculosum (Brid.), a species typical of dry and coastal environments, was used as a bioindicator for the estimation of atmospheric trace metal deposition around the industrial site ...of Portoscuso (Sardinia, Italy), which includes a lead–zinc smelter, two power plants, and aluminium production factories. For Cd, Pb, Zn, and V the results showed very similar patterns with extremely high values in the immediate surroundings of the industrial area. Copper and Cr showed somewhat different patterns, but still pointing to local pollution sources. The levels of metals at distance of about 13
km from the industrial site were still higher than in background samples. In order to evaluate the suitability of
B. radiculosum for monitoring studies, trace metal concentrations in moss were compared with bulk deposition measurements in the same area. Correlation was significant only for Pb, Cd, and Zn. For Cr, Cu, and V the results showed high variability, mainly to be ascribed to soil factors.
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.
Accumulation of lead and zinc was studied in the moss Funaria hygrometrica Hedw. collected from mine tailings. Heavy metal accumulation in gametophytes and sporophytes was quantified by graphite ...furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Pb and Zn accumulation in the placental zone was analysed by x-ray scanning electron microscopy (SEM) and transmission electron microscopy (TEM) microanalysis. Spectrometry showed that while moss gametophytes accumulated considerable concentrations of heavy metals, sporophytes accumulated only small concentrations of metals. X-ray SEM and TEM showed that the two metals accumulated in placental transfer cells on both the gametophytic and sporophytic sides. To investigate the uptake pattern for both metals under controlled conditions, F. hygrometrica plants collected from a non-polluted site were treated in the laboratory with separate solutions of Pb and Zn at two concentrations (10−2and 10−4M) for 24 or 168h. Metal accumulation was analysed separately in gametophytes and sporophytes using GFAAS and ICP–AES. Each generation had a different accumulation quotient for both metals, and gametophytes accumulated significantly more metal than sporophytes. Concentrations of Zn in sporophytes were always higher than concentrations of Pb. The findings are discussed in relation to the role performed by the gametophyte and the placenta in the accumulation and sequestration of Pb and Zn.
A comparative study of the bryophytes in some Sardinian and Corsican wetlands of major naturalistic value, such as the "padule of Suartone" (SE Corsica) and "pauli of the Giara of Gesturi" (C ...Sardinia), was carried out. In Europe, these habitats (Mediterranean temporary pond) are indicated as priority natural habitats under the Habitats Directive 92/43/EEC. In the Sardinian pauli, 56 taxa (50 Bryophyta and six Marchantiophyta) were found, while in the Corsican padule, 30 taxa (21 Bryophyta and nine Marchantiophyta) are reported. Among the bryophytes collected in the padule, the discovery of Scleropodium cespitans, Riccia perennis and Campylopus introflexus is of particular phytogeographic interest. Data are here reported together with information on the phytogeography and ecology of the recorded species.
The Mediterranean is one of the major biodiversity hotspots of the world. It has been identified as the “core” of the speciation process for many groups of organisms. It hosts an impressive number of ...species, many of which are classified as endangered taxa. Climate change in such a diverse context could heavily influence community composition, reducing ecosystems resistance and resilience. This study aims at depicting the distribution of nine orchid species in the island of Sardinia (Italy), and at forecasting their future distribution in consequence of climate change. The models were produced by following an “ensemble” approach. We analysed present and future (2070) niche for the nine species, using Land Use and Soil Type, as well as 8 bioclimatic variables as predictors, selected because of their influence on the fitness of these orchids. Climate change in the next years, at Mediterranean latitudes, is predicted to results mainly in an increase of temperature and a decrease of precipitation. In 2070, the general trend for almost all modelled taxa is the widening of the suitable areas. However, not always the newly gained areas have high probability of presence. A correct interpretation of environmental changes is needed for developing effective conservation strategies.
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