Vincenzo Zuccarello

Modelling Environmental Responses of Plant Associations: A Review of Some Critical Concepts in Vegetation Study

The definition of vegetation types at different hierarchical levels, both to study the vegetation processes and for practical cartographic representation, is still considered a critical issue in many circles of plant ecologists. The problems are mainly related to the misleading idea that classification of the vegetation system, as developed by European phytosociologists during the last century within the discipline called syntaxonomy, would imply the assumption of the organismic concept of the plant community. After a short discussion on the role of Braun-Blanquet approach in plant ecology and in landscape ecology, the methods to detect multispecies responses along environmental gradients are briefly reviewed. In the main part of this article, we intend to stress that concepts considered critical, such as plant association and its ecological niche, are just operational tools that have nothing to do with the individualistic or organismic interpretation of plant communities in vegetation studies. Important to our views on vegetation, we believe that plant associations as well as the higher syntaxa can be regarded as fuzzy sets in an operational context for describing vegetation along ecological gradients in synthetic ways and can further the understanding of vegetation variation.

Role of macrophyte communities as bioindicators of water quality: Application on the Tiber River basin (Italy)

Abstract The aquatic plant communities of the Tiber River basin have been examined to evaluate their role as bioindicators of the water quality of the Italian peninsular rivers. The compatibility curves of phytocoenoses to water chemico‐physical gradients show a correlation between the distribution pattern of the vegetation types and the water’s chemico‐physical features, such as different levels of water pollution. In particular, Fontinaletum antipyreticae, Ranunculo‐Sietum, Elodeo‐Potametum crispi and Nasturtietum officinalis develop in meso‐eutrophic and fairly clean water, Potamogeton nodosus community and Ceratophylletum demersi in eutrophic water of medium quality, while Myriophylletum spicati and especially Potametum pectinati and algal communities with Entheromorpha flexuosa are found in hypertrophic water of poor quality. These phytocoenoses can be utilised as valid bioindicators of water quality. On the contrary, Callitrichetum stagnalis, Myriophylletum verticillati, Najadetum marinae and algal communities with Cladophora glomerata are not effective bioindicators, showing a wide and sometimes unclear synecology.

Toward a framework of integrated knowledge of terrestrial vegetation system: The role of databases of phytosociological relevés

Abstract In this article, we consider the meaning of the phytosociological relevé of the Braun-Blanquets approach as a source of biodiversity matrices. We stress the importance of phytosociological relevé for the integrated vegetation studies dedicated to understand the vegetation system and its ecosystem role at different hierarchical levels. We review the state of the art of building databases of the Italian vegetation under the perspective to develop a knowledge database of Italian vegetation based on formal ontologies. This would constitute a node in the possible network of knowledge databases of European Union and of the world that is proposed within the International Association of Vegetation Science.

Saponins from Tribulus terrestris L. protect human keratinocytes from UVB-induced damage.

Chronic exposure to solar UVB radiation damages skin, increasing the risk to develop cancer. Hence the identification of compounds with a photoprotective efficacy is essential. This study examined the role of saponins derived from Tribulus terrestris L. (TT) on the modulation of apoptosis in normal human keratinocytes (NHEK) exposed to physiological doses of UVB and to evaluate their antitumoral properties. In NHEK, TT saponins attenuate UVB-induced programmed cell death through inhibition of intrinsic apoptotic pathway. In squamous cell carcinomas (SCC) TT saponins do not make the malignant keratinocytes more resistant to UVB and determine an enhanced apoptotic response. The photoprotective effect of TT saponins is tightly correlated to the enhancement of NER genes expression and the block of UVB-mediated NF-κB activation. Collectively, our study shows experimental evidence that TT has a preventive efficacy against UVB-induced carcinogenesis and the molecular knowledge on the mechanisms through which TT saponins regulate cell death suggests great potential for TT to be developed into a new medicine for cancer patients.

A new species of Isoetes (Isoetaceae, Pteridophyta) for the Mediterranean

Abstract Isoëtes iapygia from the Apulia region (southern Italy) is described as a new species and illustrated. It differs in several characters from the other Mediterranean Isoëtes species, but has some intermediate characteristics similar to terrestrial and amphibious Isoëtes. I. iapygia is similar to the amphibious species for the lack of phyllopodia, even if it has scales; it is similar to terrestrial species for the complete velum and tuberculate macrospores. A completely unique character is represented by the two air chambers. Its habitat is on limestone rocks, in temporary pools.

Natural habitats of typical plants growing on ruins of Roman archaeological sites (Rome, Italy)

In this study, we support the hypothesis that wall plant species come mainly from rocky habitats, taking into account that ancient walls show similar characteristics to rocks. The occurrence of wall species in natural habitats was investigated. The main literature concerning wall and natural vegetation of central-southern Italy was viewed. Vegetation synoptic tables were analysed through statistical procedures for comparing occurrence and behaviour of wall species in ruderal habitats as archaeological sites and natural ones.The study pointed out that wall species show similar ecological and coenological features in both habitats. This confirms that the main natural habitat from which wall species come from are rocks, but secondarily also ephemeral Mediterranean meadows and garrigues. Particularly, some wall species belonging to Parietarietea judaicae class are participating in the formation of natural rocky communities of Asplenietea trichomanis. Species occurring on emerging ruins form ephemeral meadows belonging to Helianthemetea guttati, also found in natural Mediterranean environment. On wide tops of ruins, where community dynamism is higher, some perennial herbaceous and shrubby species participate in the formation of impoverished communities matching to natural aspects of Mediterranean maquis. The knowledge of the natural habitat of wall species can be useful for a better management of archaeological sites.

Pedodiversity deserves attention in plant biodiversity research

We suggest that pedodiversity, an expression of environmental heterogeneity, should deserve the attention of plant ecologists interested to study the spatial pattern of plant biodiversity at different scales. Using the FAO pedological and the IUCN-WCMC biological data bases of the world countries, we show that the prediction on plant biodiversity (number of vascular plants) improves significantly when the extent of the area is combined with pedodiversity in a multiple polynomial regression. Partial correlation analysis proves that, by removing the effect of pedodiversity, the correlation “number of species–area” remains statistically significant for the tropical countries while it loses significance for the countries outside the tropics.

Ecological comparison between duckweeds in central Italy: The invasive Lemna minuta vs the native L. minor

Abstract The American duckweed Lemna minuta shows an invasive behaviour in Europe, causing weed problems in aquatic habitats there. Few studies addressed this species’ ecological requirements for a suitable establishment in a site. In this paper, L. minuta populations were analysed through field surveys so as (1) to define the autoecology of this duckweed as regards the main environmental factors characterizing invaded habitats, and (2) to identify possible overlaps/differences in ecological requirements between the alien L. minuta and the common native L. minor, with which it is often associated and in direct competition. The occurrence/abundance of the two species and environmental data were collected from 41 wetlands in central Italy. Currently, L. minuta is more common and abundant than L. minor in the study-area, despite its recent arrival there (2007). The two species have a partially overlapped autoecology. However, L. minuta differs from L. minor since it occurs in waters which are less alkaline, slightly less warm, and richer in nitrates. It shows tolerance for environmental conditions which are limiting for most of macrophytes, including L. minor, such as high shading and low water oxygenation. This enables L. minuta to increase its invasion potentiality and thus to enlarge its distribution area.

Project “Biodiversity MARE Tricase”: biodiversity research, monitoring and promotion at MARE Outpost (Apulia, Italy)

The project “Biodiversity MARE Tricase” aims to research and promote coastal and marine biodiversity at the MARE Outpost (Avamposto MARE), a marine station established in Tricase (Lecce, Italy) in 2015. From March 2016 to September 2017, the first biodiversity inventory of the Tricase coastal area (Ionian Sea) was realized with the aid of citizen scientists (e.g. local fishermen, divers, bathers, and tourists). Preliminary results include 556 taxa, of which the 95% were identified at the species level. Despite the broad knowledge on Mediterranean coastal biodiversity, 71 species represented new records for the Ionian Sea. In parallel with the research activities, people’s awareness of the value of biodiversity was raised with scientific dissemination initiatives, involving about 1700 people. The “Biodiversity MARE Tricase” project realized a first small-scale species inventory contributing to the distributional, taxonomic, and ecological knowledge of the present Mediterranean biota. The coastal area of Tricase will be soon included in a new Marine Protected Area and this project represents a step forward for the sustainable development of the community of this coast.

Ecological responses of selected vascular plants to water chemistry parameters in habitat types 3120, 3130 and 3170* (Habitat Directive 92/43/EEC)

Abstract The article aims to examine the main water chemistry parameters (i.e. conductivity, pH, dissolved O2) and the ecological responses of 20 guide species in Mediterranean Temporary Ponds (MTPs). A complete data-set of 37 MTPs located in two different regions of Italy, Sardinia and Apulia, was compiled and the data were examined by means of Principal Component Analysis (PCA). The pattern of MTPs into the water chemistry space showed a clear separation between the two geographical regions. A “daisy diagram” obtained by overlapping five typologies of MTPs, obtained by the fuzzy cluster analysis and the PCA, revealed a good agreement between the sequence of groups and the water chemistry gradient. Groups of species sharing similar responses to the same chemical features were finally identified. These groups could be effective to acquire detailed information on the characteristics of MTPs and to improve their classification into different typologies. The guide species respond selectively to the wide variability range of conductivity, pH and dissolved oxygen. Despite the small size and the short hydroperiod water parameters in MTPs presented specific patterns to which the guide species are able to give specific responses.