The aim of the present work was to assess the conservation status of coastal dune systems in Tuscany (Italy). Emphasis was given to the presence and abundance of plant communities identified as ...habitat in accordance with the Directive 92/43/EEC. Twenty transects perpendicular to the shoreline were randomly positioned on the whole coastal area (30 km in length) in order to sample the full spectrum of plant communities. Vegetation zonation and relationships with the most frequent disturbance factors in the study area—beach cleaning, coastline erosion, presence of paths and roads, bathing settlements and trampling—were investigated through principal coordinate analysis and canonical correspondence analysis. Natural factors, such as distance from the sea and total length, were also considered. Differences in the conservation status of the sites were found, ranging from the total disappearance of the foredune habitats to the presence of the complete psammophilous (sand-loving) plant communities. Erosion, trampling, and paths were found to be closely correlated with degradation and habitat loss. Furthermore, the overall plant species diversity of dunes was measured with NHDᵤₙₑ, a modified version of the Shannon index; while the incidence of invasive taxa was calculated using N, a naturalness index. However, these diversity indices proved to be a weaker bioindicator of ecosystem integrity than habitat composition along transects. A possible strategy for the conservation and management of these coastal areas could be to protect the foredunes from erosion and limit trampling through the installation of footbridges or the use of appropriate fences.
Plant communities of coastal dunes are distributed along a characteristic sea-inland gradient. Generally, there is a shift from annual and short height species with small leaves in the initial ...successional stages to perennial tall shrubs with tough leaves in later phases. Assessing the community-weighted mean (CWM) trait values is used in plant ecology to describe ecosystem properties especially during succession. In particular, CSR (Competitive, Stress-tolerant, and Ruderal strategy) classification allows us to explore community functional shifts in terms of disturbance, stress and competition selective forces. The functional basis of the psammophilous succession was studied based on the following questions: (1) Can we circumscribe different functional types among plant species of Mediterranean coastal dunes? (2) How do CWM trait values vary along the environmental sea-inland gradient? (3) What is the relative importance of competition, stress and disturbance in the processes of plant community assembling? (4) Can we postulate that along primary successions there is generally a shift from ruderality to stress-tolerance? An explorative analysis of functional groups was performed by Non-Metric Multidimensional Scaling (NMDS) analysing nine morpho-functional traits measured for 45 taxa from 880 dune plots localised in Tuscany (central Italy, Europe). NMDS ordination showed a scattered distribution of psammophytes that could not be delimited in precise plant functional types. The first NMDS axis has been interpreted as a leaf economics axis because it was correlated to leaf area (LA) and leaf dry matter content (LDMC), while the second one was a plant size axis because of its correlation with canopy height. Along the sea-inland gradient, pioneer plant communities of upper beach were dominated by ruderals (with the lowest values of LDMC and specific leaf area - SLA), well-adapted to the harsh environmental conditions of coastal dunes. More distant from the sea, where ecological conditions were less extreme, late-successional communities of backdunes were characterised by the prevalence of stress-tolerance. This study suggested that psammophytes have evolved not a single but multiple adaptive strategies showing a high degree of functional diversity and complexity. Moreover, CSR classification supported the hypothesis of a functional shift from R-strategists in early successional stages to S-strategists in late-successional communities along a primary succession.
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•Psammophytes display high functional diversity and complexity.•Stress and disturbance drive Mediterranean coastal dune succession.•CSR classification is a useful tool to resolve primary successions.
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•EOs composition and volatiles emission of four Sicilian sumac samples were analysed by GC-FID and GC–MS for the first time.•Non terpenic compounds were present as main constituents, ...mainly represented by aldehydes.•EO composition is quite similar in three of the four samples except for CG where p-anisaldehyde showed the high percentage in comparison with the others.•Main oil components in R. coriaria fruits were p-anisaldehyde, (Z)-2-heptenal, (E)-2-decenal, β-caryophllene and cembrene.
The volatile fractions and essential oils from Rhus coriaria fruits collected in four locations in Sicily (Italy) were characterized by GC–FID and GC–MS analysis. Monoterpenes were identified as the main class of constituents in volatiles spontaneously emitted by sumac fruits collected in two of the four sites (42.1–59.9% in ‘CNS’ and ‘CIN’ respectively), while non terpenic compounds predominated in the other two (46.1–52.8% in ‘MR’ and ‘CG’, respectively). The EO composition were characterized by high amount of non terpenic compounds (from 27.5 to 55.1%), followed by sesquiterpenes and diterpenes. p-anisaldehyde was the main constituent both in volatiles emitted by ‘CG’ sample and in its essential oil (28.4 and 20.8%, respectively). The comparison between the EOs obtained from the Sicilian samples differed from the EO obtained from sumac fruits purchased on the Jordanian market, even though a similar composition were evidenced with Turkish samples reported in the literature.
Since coastal dunes are one of the most vulnerable landscapes in Europe, their maintenance requires specific conservation and monitoring programmes. In this paper, the coastal dune systems of two ...natural parks located in central Italy were analyzed aiming at: (1) assessing diversity patterns of all vascular species, endemic and alien taxa in plant communities along the coast-to-inland gradient; (2) comparing these patterns between coastal sections characterized by different dynamical processes (accreting, stable and erosive coasts); and (3) testing the differences induced by the methodological approach used to characterize these patterns. Twenty-one transects were randomly positioned perpendicular to the shoreline in the whole coastal area (30 km in length), and the full spectrum of plant communities was sampled. Patterns of plant diversity were assessed using spatially explicit methods, namely spatial constrained rarefaction (SCR), able to avoid the confounding effect of spatial autocorrelation. The results show that species richness varied significantly between plant communities along the coast-to-inland gradient with the highest values at the level of mobile dunes and transition dunes. Species richness was significantly higher in stable coastal dunes than those found in accreting and in erosive dunes. In fact, sand dynamics (accumulation as well as erosion) create periodic vegetation disturbances affecting composition variability and succession. The SCR methodology avoided overestimation of species richness when compared to classical rarefaction curves. Our findings pinpointed that coastal plant communities create a highly spatially structured mosaic in which mobile dunes represent the highest compositional heterogeneity. Local managers are encouraged to consider these results for planning adequate conservation strategies.
The Mediterranean basin is characterised by increasingly dry summers and the study of the adaptive traits developed by plants living in this stressful environment is of great interest, also in ...relation to climate projections for this area.
Cistus monspeliensis, Myrtus communis and Phillyrea angustifolia are three co-occurring shrubs typical of the Mediterranean maquis. Their functional and physiological parameters were studied in spring, summer and autumn in order to highlight adjustments of these traits and to test eventual different adaptive strategies.
Soil and leaf chemical characteristics were determined in the different seasons. Leaf area, specific leaf area, leaf dry matter content, succulence index, pigment contents hydric status and main markers of oxidative stress and antioxidant response were detected.
The stressful summer season induced disturbance in hydric balance, decrease in succulence index and chlorophyll content and high contents of hydrogen peroxide. Thanks to higher enzymatic activities and total glutathione content, in the two evergreen species M. communis and P. angustifolia oxidative damage remained at levels equal to or lower than the other seasons. Only in the semideciduous C. monspeliensis both functional and biochemical traits showed a higher stress condition in summer. The higher stability of functional traits in the two evergreen species may be explained by the sclerophyllous nature of their leaves. Four environmental variables – Tmax, Tmin, soil conductivity and organic matter – mostly influenced NMDS segregation of these species.
•Classic rarefaction methods were shown to be susceptible to spatial autocorrelation.•Spatially Explicit Rarefactions account for the spatial autocorrelation in community data.•Including spatial ...autocorrelation into rarefactions change the way nature reserves are prioritized.
Recently, methods for constructing Spatially Explicit Rarefaction (SER) curves have been introduced in the scientific literature to describe the relation between the recorded species richness and sampling effort and taking into account for the spatial autocorrelation in the data. Despite these methodological advances, the use of SERs has not become routine and ecologists continue to use rarefaction methods that are not spatially explicit. Using two study cases from Italian vegetation surveys, we demonstrate that classic rarefaction methods that do not account for spatial structure can produce inaccurate results. Furthermore, our goal in this paper is to demonstrate how SERs can overcome the problem of spatial autocorrelation in the analysis of plant or animal communities. Our analyses demonstrate that using a spatially-explicit method for constructing rarefaction curves can substantially alter estimates of relative species richness. For both analyzed data sets, we found that the rank ordering of standardized species richness estimates was reversed between the two methods. We strongly advise the use of Spatially Explicit Rarefaction methods when analyzing biodiversity: the inclusion of spatial autocorrelation into rarefaction analyses can substantially alter conclusions and change the way we might prioritize or manage nature reserves.
Salvia rosmarinus Spenn. and Salvia jordanii J.B.Walker are aromatic evergreen shrubs belonging to the Lamiaceae family. Their aerial parts have been used since ancient times as natural ...preservatives. The present study reported the investigation of the chemical profile and the extraction yield of the essential oils (EOs) obtained from the dried aerial parts of four cultivars of Salvia rosmarinus (‘Boule’; ‘Vicomte de Noailles’; ‘Gorizia’; ‘Joyce de Baggio’) and the species S. jordanii, together with their antibacterial and antifungal activities. The phytochemical investigation evidenced a predominance of oxygenated monoterpenes in all the samples (57.5–77.1%), except in ‘Boule’, in which the hydrocarbon form prevailed (50.2%). Principal Component Analysis (PCA) of the matrix taxa × compounds showed that nine compounds have a significant discriminating function between the samples. ‘Vicomte de Noailles’ was characterized by high amounts of camphor and 14-hydroxy-9-epi-(E)-caryophyllene, while ‘Gorizia’ and Jord differed in their predominance of camphene, borneol, bornyl acetate, and α-humulene. Lastly, ‘Boule’ and ‘Joyce de Baggio’ segregated separately and were characterized by high amounts of α-pinene, myrcene, and verbenone. The selected EOs presented a moderate antibacterial activity on the tested bacterial strains and resulted not active on the tested yeast species.
Anthemis maritima, a plant which has the ability to colonise different stressful coastal environments, sand dunes and rocky cliff ecosystems, exhibits a high degree of leaf trait plasticity. The key ...parameters are the regulation of stomatal density and size, the succulence index and the specific antioxidant response. With the aim to explore plant plasticity, we analysed various morphological and physiological traits of the leaves of A. maritima populations dwelling in three different coastal areas of Italy. The highest values of stomatal density, leaf thickness, and succulence index were found in plants living in a sub-arid climate, on rocky cliffs, with the highest soil pH and salinity. Although this population exhibited the highest concentration of oxygen reactive species (hydrogen peroxide), it also had the lowest value of lipid peroxidation, an indicator of oxidative stress. Ascorbate was the main protective molecule in this population, while phenols appeared to carry out this role in plants living on soils with the lowest salinity and highest annual rainfall.
•Stress response in Anthemis maritima plants from different coastal habitats.•Higher stomatal density, leaf thickness, succulence index in more stressed plants.•Phenols and ascorbate: main antioxidants in response to coastal constraints.•A. maritima may be a useful model to understand plasticity of adaptive mechanisms.
In this contribution, new chromosome data obtained on material collected in Italy are presented. It includes counts from six populations of three taxa within the genus
Pulmonaria
, two of which are ...endemic to Italy (P. vallarsae subsp. apennina and P. vallarsae subsp. vallarsae); the other is the widespread European
P. officinalis
. In addition, two counts from
Potentilla detommasii
and
Stachys thirkei
, two eastern Mediterranean species, are also reported.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Coastal dunes are characterised by strong interactions between biotic and abiotic factors along a short gradient from the shoreline to the inland region. We carried out an ecological analysis of the ...vegetation in a protected area of the Italian coast to evaluate the relationships among species abundance, the occurrence of morphoanatomical traits related to leaves, stems, and roots, and soil variables. Three transects were established perpendicular to the shoreline, with 27 plots distributed in the frontal dunes, backdunes, and temporarily wet dune slacks. An analysis based on community-weighted mean values showed that the pioneer communities of the frontal dunes were dominated by ruderals that are well adapted to the harsh ecological conditions of these environments, showing succulent leaves, high limb thickness values, and low values for leaf dry matter content (LDMC). The backdune vegetation was a mosaic of annual herbaceous and perennial shrub communities showing both ruderal and stress-tolerant strategies (clonality, sclerified leaves, high LDMC values, root phenolics) consistent with less extreme ecological conditions. The dune slack areas were dominated by plants showing adaptations to both arid and flooded environments, such as C4 photosynthesis, amphistomatic leaves, and abundant aerenchyma in the roots. The invasive status, C4 photosynthesis, leaf trichomes, and aerenchyma in the roots were significantly correlated with soil humidity, organic matter content, and pH. These results demonstrate the usefulness of anatomical traits (including root system traits) in understanding the functional strategies adopted by plants. Invasive species tended to occupy plots with high levels of soil moisture, suggesting an avoidance strategy for the harsh environmental conditions of coastal sand dunes. Finally, we suggest including information regarding root systems into coastal monitoring programs because they are directly linked to soil parameters useful in coastal dune management and protection.
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