Geometric morphometrics as a tool to resolve taxonomic problems: the case of Ophioglossum species (ferns)

A modern method, geometric morphometrics, was used to clarify the taxonomic position of the European Ophioglossum species: O. azoricum, O. lusitanicum, and O. vulgatum. The identification of these taxa by traditional methods is rather difficult, due to different taxonomic interpretations. Sterile leaf shapes were investigated using a landmark-based method and the Fourier analysis of outlines. Both methods highlight the shape and the base of the leaf as an important diagnostic character

La vegetazione del Parco Regionale Marturanum (Lazio settentrionale, Italia entrale): lineamenti fitosociologici e genesi del paesaggio vegetale

The Marturanum Regional Park is a small protected area (1,240 hectares), however it is placed along the interface between two of the main lithological units of Lazio, hence featuring a high diversity of flora, vegetation and landscape. Further, it includes a small part of theMonti dellaTolfa, a 30,000 hectares hilly rangewhich features an exceptionally low population density. The Tolfa hills are a biodiversity hotspot of C-Italy and show a very distinctive landscape pattern. The present paper outlines a phytosociological classification and syntaxonomical discussion of the numerous plant communities found in theMarturanumPark.The presentwork describes also the different role of the natural constraints and of the historical and cultural processes that have led to the peculiar landscape patterns nowadays found in the area, and in particular to the differentiation between the two landscape systems of the pyroclastic flow and the Tolfa flysch.Parco regionale Marturanu

A comparative study of the seed germination capabilities of Anacamptis palustris (Orchidaceae), a threatened terrestrial orchid, and other more common Anacamptis species, by asymbiotic culture in vitro

The increasing emphasis on terrestrial orchid conservation has led to conservation actions for a wide range of threatened Mediterranean species. Many terrestrial orchids are currently at great risk for extinction as a result of a multiplicity of threatening processes. We focus on orchid seed germination capabilities in vitro, specifically germination capability of a threatened species, Anacamptis palustris, compared to three other more common species (A. laxiflora, A. morio, and A. papilionacea), and also discuss its potential impact on orchid distribution and conservation. Asymbiotic germination tests were performed with mature seeds using BM-1 medium. In vitro seed germination and protocorm developmental stages were evaluated up to 20 weeks after sowing. Significant differences in seedling development were detected among the species, and a correlation was evident between the rarity of the species and their germinability. Thus, the presence of intrinsic, biological factors that affect and limit the distribution of A. palustris may exist

Outline analysis for identifying Limodorum species from seeds

Limodorum trabutianum Batt. is an orchid species of the Italian flora, with a central-western stenomediterranean distribution, that is sporadic in the western part of the distribution area of the more common L. abortivum (L.) Sw., an eurimediterranean species. It occurs in Italy only with a few populations in Tuscany, Latium, Umbria, Sicily and Sardinia [1], often with L. abortivum [2], [3], [4] from which it is easily recognizable only during anthesis for the denser inflorescence spike, the ribbon-like lip without differentiation in epychile and hypochile, and for the spur that is very short or absent [5]. On the contrary, the identification of these two taxa during the fruiting phase is rather difficult or even impossible. The aim of this study is to verify the taxonomic value of Limodorum seeds, particularly of their shape, as highlighted from recent studies for other orchids [6], [7], in order to establish its usefulness for recognizing the two species. We have identified 5 Italian populations of the two taxa: 2 populations of L. trabutianum, one within the Marturanum Regional Park (Barbarano Romano, Viterbo), the other near Cortona (Arezzo), and 3 populations of L. abortivum, near S. Martino al Cimino (Viterbo), in the M. Casoli Reserve (Bomarzo, Viterbo), and in the same site of L. trabutianum within the Marturanum Park. The phenology of these populations was monitored to collect mature seeds from naturally dehiscing capsules. The intra- and interspecific variability of seed shapes was analyzed with the methodology of Elliptic Fourier descriptors [8], which allows to describe in terms of harmonics each two-dimensional shape with a closed outline. For this outline analysis we used the software package SHAPE 1.3 [9]. An average of 100 seeds from each species and from each site was photographed with a NIKON Coolpix 5000 camera mounted on a LEITZ-ARISTOPLAN microscope, obtaining 500 digital images with a resolution of 300 dpi and a size of 800 x 1000 pixels. All images were prepared using Adobe Photoshop 7.0: as a first step, every foreign element was eliminated from the picture, thereby isolating the single seed, then its contrast with the background was maximized, and finally all images were saved in .bps format (24bit). The color images were converted to binary with Chain Coder before tracing the outlines in Chain-code, a coding system that describes the geometrical information of the shapes. Then the Chain-code file was transformed into a Normalized Elliptic Fourier file using Chc2Nef using 20 harmonics. The matrix of the harmonic coefficients underwent a process of data normalization based on the first harmonic, to transform the data into shape variables. Subsequently, a PCA was performed on the variancecovariance matrix of normalized coefficients using PrinComp, which gives a graphical output of the principal components (average shape ± standard deviations). The first results of the outline analysis confirm a low intraspecific variability of seed shape, but show a very high interspecific variability: L. abortivum seeds are very elongated, from fusiform to filiform, while L. trabutianum seeds are much wider and have a very lower length/ width ratio. These results allow to distinguish between these two species even during the fruiting phase, simply using seed shape as a diagnostic character, avoiding the use of traditional morphometric analysis which need microscopic measurements

A comparative study of the seed germination capabilities of Anacamptis palustris (Orchidaceae), a threatened terrestrial orchid, and other more common Anacamptis species, by asymbiotic culture in vitro

The increasing emphasis on terrestrial orchid conservation has led to conservation actions for a wide range of threatened Mediterranean species. Many terrestrial orchids are currently at great risk for extinction as a result of a multiplicity of threatening processes. We focus on orchid seed germination capabilities in vitro, specifically germination capability of a threatened species, Anacamptis palustris, compared to three other more common species (A. laxiflora, A. morio, and A. papilionacea), and also discuss its potential impact on orchid distribution and conservation. Asymbiotic germination tests were performed with mature seeds using BM-1 medium. In vitro seed germination and protocorm developmental stages were evaluated up to 20 weeks after sowing. Significant differences in seedling development were detected among the species, and a correlation was evident between the rarity of the species and their germinability. Thus, the presence of intrinsic, biological factors that affect and limit the distribution of A. palustris may exist

The dry grasslands of Abruzzo National Park, the oldest protected area in the Apennines (Central Italy): overview of vegetation composition, syntaxonomy, ecology and diversity

The Abruzzo, Lazio and Molise National Park was established in 1923 and is considered a flagship conservation area in Italy. It includes large extensions of semi-natural grasslands, maintained by traditional transhumant grazing for centuries. The patterns and drivers of grassland composition within the Park are still poorly investigated, and the scattered phytosociological data available were often based on relevés with varied and not precisely defined sizes. In order to provide for the first time a general overview of the Park’s dry grasslands, we analysed a dataset of 87 relevés with a fixed size of 2 × 2 m, precisely delimited in the field and GPS-located. Specific research aims were: (1) to classify the vegetation plots into floristic-ecological types, supported by an analysis of mean (Italy-specific) Ellenberg Indicator Values (EIVs); (2) to assign the types to up-to-date phytosociological syntaxa; (3) to identify the main environmental drivers for both composition and richness patterns; (4) to test the degree of correlation between (Italy-specific) EIVs and the measured environmental variables. Environmental predictors included high-resolution climatologies and remote-sensed standing biomass. Main vegetation types were identified using Hierarchical Cluster Analysis (HCA). Distancebased RDA was performed as a constrained ordination method to reveal correlations between floristic composition and environmental variables. Drivers of species richness were explored through partial correlation and Regression Trees. HCA and NMDS revealed four floristically and ecologically well-interpretable groups, in turn well corresponding to the level of phytosociological class (namely Molinio-Arrhenatheretea, Nardetea strictae, Festuco hystricis-Ononidetea striatae and Festuco-Brometea). Constrained ordination showed that most of the floristic variation was explained by biomass, annual precipitation (Pann) and mean annual temperature (Tm). Strong and significant positive correlations were found between biomass and EIV for Nitrogen (EIV-N), and between Tm and EIV for Temperature (EIV-T). Strong and significant negative correlations were found between Pann and EIV-T, EIV for Continentality (EIV-C) and EIV for soil Reaction (EIV-R). Species richness was positively correlated with slope inclination and negatively with elevation; richness was higher in sites with a high rock cover, and on limestone or clayey substrata than on siliceous ones. We conclude that in the study area: a) dry semi-natural grasslands are arranged at least into four distinguishable, high rank floristic-ecological groups; b) a mixture of climatic (especially precipitation) and edaphic (especially bedrock and soil reaction) gradients are the main drivers of such composition patterns; c) species richness is higher in sites more stressed by summer drought and/or nutrient scarcity; d) community-means of Italy’s specific EIVs are well correlated with environmental variables in grasslands, including a good correspondence between EIV-T and mean annual temperature

Effectiveness of different metrics of floristic quality assessment: The simpler, the better?

Vascular plants are good environmental indicators. Thus, floristic inventories have a high potential in environmental management since they reflect the current and past status of the environment. In this study, we used the flora of a suburban riverscape in central Italy to test the performance of the Floristic Quality Assessment (FQA) approach, an expert-based evaluation technique. Ten expert botanists assigned coefficients of conservatism (CC) to 382 plant species. We found statistically significant differences between the values assigned to the inventoried flora by botanical experts. In spite of this, the analysis of pseudo multivariate dissimilarity-based standard errors of CC values assigned by the different experts revealed that, in our case, an assessment by a minimum of five botanists allows characterizing the flora with a stable level of precision. We used the distance from agricultural and urban surfaces as a proxy of anthropogenic disturbance to divide the area around the river in four belts of increasing disturbance. The disturbance gradient was mirrored by median CC values and by the Adjusted Floristic Quality Assessment Index (Adjusted FQAI). Conversely, the Floristic Quality Assessment Index (FQAI), which is based on CC values and on the number of native species, showed increasing values with increasing disturbance. Comparing the performance of median CC values to Ellenberg Indicator Values (EIVs), life forms, and chorotypes, we revealed that the last three indicators may be ineffective in highlighting the conservation status of the environment. We suggest that the use of the median CC values may be a simpler and effective alternative to the calculation of indices in FQA, when the adequacy of the number of experts in minimizing the variability of CC values is a posteriori verified