Francesco Spada

VegItaly: The Italian collaborative project for a national vegetation database

Abstract Two years after its official start, the national vegetation database VegItaly, a collaborative project supported by the Italian scientific community and developed by a large group of scientists, is presented. This article offers a concise overview of the content of the database, currently consisting of 31,100 vegetation plot, including published and unpublished data. Some basic statistics are analysed; for example, data distribution in space and time, represented vegetation types expressed as physiognomic categories. Although rather young and still in progress, VegItaly already contains data from all the Italian regions and stands as an optimal candidate for the development of an Italian national vegetation database. Its main goals,theoretical basis, technical features, functionalities and recent progresses are outlined, showing glimpses of future prospects.

Multiple genome relationships and a complex biogeographic history in the eastern range of Quercus suber L. (Fagaceae) implied by nuclear and chloroplast DNA variation.

Abstract The complex evolutionary history of Quercus suber has been throughly investigated in many recent works, but the details of its differentiation processes are still largely unknown. In addition, the geographical and evolutionary roles of the eastern parts of the species range have gained much less attention compared to other southern European areas. In order to fill this gap, new insights to infer the species diversification and range establishment of the cork oak in the east-central Mediterranean are here provided by means of inter- and intra-specific plastid DNA and nuclear ribosomal ITS phylogeographic studies. We analyzed 95 natural cork oak populations; 6 closely related, sympatric oaks were included in the study and used for comparisons. Evidence for a clear phylogeographical structure was detected with PCR-RFLP at 5 chloroplast loci, while ITS sequence variation is apparently unrelated with the geographical distribution. Five chloroplast haplotypes and three ITS main lineages were identified. Three haplotypes and all ITS lineages occur in the Italian Peninsula, stressing the importance of these territories for the evolutionary history of the species. Two divergent “Italian” haplotypes are highly shared, and one ITS variant is basal to the ingroup, revealing sister relationships within Cerris taxonomic group. Hypotheses of hybridization, lineage sorting of ancient DNA polymorphisms and of reticulate evolution of the whole species group are presented and discussed.

Quercus macranthera Fisch. & Mey. ex Hohen. and Quercus iberica M. Bieb.: Taxonomic definition and systematic relationships with European oaks inferred from nuclear internal transcribed spacer (ITS) data

Abstract Systematic relationships of the two most widespread oaks in Armenia, Quercus iberica M. Bieb. and Quercus macranthera ssp. macranthera Fisch. & Mey. ex Hohen. (Fagaceae), were examined by means of internal transcribed spacer (ITS) sequence variation. The analysis included recently published and several newly derived ITS fragments of most common Eurasian Quercus spp. Orthology of sequences was supported by inspection of ITS secondary structure features. Analyses were implemented with parsimony and maximum likelihood criteria to check the position of all taxa. The robustness of the phylogenetic hypothesis was tested with bootstrap, decay, and Bayesian analysis. Three main clades emerged from the root, corresponding to subg. Quercus, Cerris, and Sclerophyllodrys. Q. iberica and Q. macranthera were included in the subg. Quercus clade and related to Quercus petraea and Q. frainetto-Q. pyrenaica, respectively. The taxonomical status of Q. iberica (Q. petraea ssp. iberica according to some authors) was analysed with respect to Q. petraea. Despite the strict phylogenetic relationship among these two species, the genetic distance (Kimura) was compatible with the hypothesis of maintaining the two taxa separated. A hypothesis on the differentiation of Q. iberica and Q. macranthera before the last glaciation, and their subsequent re-expansion from glacial refugia located in the southern shores of the Black Sea, is proposed. Q. petraea ssp. huguetiana (sequenced for the first time in this study) turned out to be an outgroup with respect to the clade formed by the other accessions of Q. petraea (including Q. iberica). On this basis, this taxon could also assume specific status. The phylogenetic position of Q. pyrenaica is discussed for the first time.

A dendrochronological analysis of Pinus pinea L. on the Italian mid-Tyrrhenian coast

In order to assess the response of the radial growth of Pinus pinea L. to climatic variability in Central Italy, dendrochronological and dendroclimatological analyses were carried out on five different populations scattered along the Tyrrhenian coasts of the peninsula. The aim of this study is to contribute to the understanding of the ecological demands of this species, particularly in the study area.For each site total ring, early-, and late-wood width chronologies were developed.Multidimensional analyses were performed for the three tree-ring datasets in order to analyze the relations between sites chronologies. Both Principal Component Analyses and hierarchical classifications highlighted an important difference of one site in respect to the other, probably due to site characteristics.Correlation functions were performed to infer the main climatic factors controlling the radial growth of the species. For a comparative study, we limited our attention to the common interval 1926–2003 (78 years) in which the response of the tree-ring chronologies to climate at both local and regional scale was investigated.Positive moisture balance in the late spring-summer period of the year of growth is the climatic driver of P. pinea radial growth in the study area. Moreover, this study shows how low summer temperatures strongly favor the radial growth of the species.

Deciduous Broadleaved Versus Evergreen Sclerophyllous Forests. Disturbance and Local Shifting Dominance in Mediterranean Environments.

On promontoria and rocky headlands of a shoreline of subemergence, along the west coast of Central and Southern Italy, where, different fire, regimes have been occurring, vegetation ranges from mediterranean sclerophyllous Quercus ilex forests and thickets, to Pinus alepensis groves, garigue, phryganic and steppic communities. Nowadays, mixed broadleaved forests show restricted distribution in the strict Mediterranean district though deciduous specie are often encountered. Their presence has been interpreted as extrazonality. However, pollen analysis provided evidence that during the upper Pleistocene, the Mediterranean forests were limited in their extension, whereas deciduous oaks showed a much larger diffusion (5). Since that time, dramatic climatic changes and increasing human activity have largely affected the vegetation landscape in these areas.

The Status of Quercus pubescens Willd. in Europe

Taxonomic and nomenclatural disagreements are still encountered in the study of Quercus pubescens Willd. in Europe and are discussed here. This includes two current antithetical viewpoints on this taxon, i.e. the acceptance of the huge phenotypic variability among and within its populations within a single species vs. the ranking of these phenotypes as distinct species within the subgenus Quercus (the European white oaks sensu Schwarz).

Quercus suber Distribution Revisited

The complex evolutionary history of Quercus suber is still under debate. Also, data and evidence at the eastern end of the species range are largely incomplete. In this study, historic floras, fossil data, and local toponyms were surveyed and genetic analyses and linguistic research used in order to point towards a previously neglected occurrence of Q. suber east of Italy. Such a multidisciplinary approach depicts a scenario in which cork oak survived in the Balkan Peninsula until recently and suggests how Q. suber might have been evicted and relegated westward, due to climate changes, ecologic competition and human impact. Our findings also suggest that the differentiation core of Q. suber was in a yet unidentified area corresponding to present-day central Europe to southwestern Asia. Radiation occurred during the Middle Miocene, with a later extension into southern Europe, Iberia and North Africa, as documented by samples collected from the late Miocene-early Pliocene. The causes of extinction in the east, however, should be investigated further and may lead to investigations about other species that might have experienced range shifts similar to that of cork oak.

Phenorhythms and Forest Refugia

Anomalous phenoryhthms such as reiterated anthesis and annual, biennial and intermediate fruiting are recorded for evergreen oaks (Quercus sect. Sclerophyllodrys: Q. ilex, Q. coccifera s.l. and Quercus sect. Cerris: Q. suber) in southern peninsular Italy. The same patterns are known from populations of evergreen oaks of the same sections in the western Himalaya, in areas where climatic conditions are intermediate between mediterranean and monsoons regimes, thus resembling border-line mediterranean climates. This suggests persistence of atavistic adaptations in areas with similar, “relaxed” climatic conditions. In the Italian peninsula, such areas would have acted as small isolates where a less intense climatic deterioration during the Late Quaternary affected the forest stands that survived across pleni-glacial events, preserving the main features of evergreenness with anomalous phenorhythms. These areas are today particularly dense in Arctotertiary taxa of Caucasian affinity, which coexist where oak populations with anomalous phenorhythms have been recorded. This suggests that present-day anomalies in reproductive cycles, along with a rich woody flora and local altitudinal zonations with mixed forest stands of Caucasian affinity, might represent the legacy of cryptic forest refugia during the last pleni-glacial.

La hêtraie pluri-séculaire de la vallée Cervara (Parc national des Abruzzes, Italie)

Abstract The oldest beech forest of Europe was found in the Apennines. The stand is located in valle Cervara (Abruzzo national Park) and it covers about fifty hectares from 1 400 to 1 800 m a.s.l. The forest is characterized by a mosaic of patches in different phases of development from seedlings to senescent and dead trees. Some trees reach five hundred years, two fold the maximum age reported for the species. The dendrochronological analysis of the tree-ring series showed tree growth variations which occurred in the forest since the Little Ice Age (1600–1850). The reconstruction of the past climate is an important step to understand the role of human activities in the present climatic global change. This study will be also useful to define a model of forest management that take into consideration the natural cycle of beech forests.

Introduction: Vegetation science and the habitats directive: approaches and methodologies of a never-ending story

Rendiconti Lincei has dedicated a Special Issue to present a number of case studies highlighting the role played by the European Vegetation Survey Working Group established by Sandro Pignatti and his colleagues in support to the implementation of the Habitats Directive. Studies include theoretical analyses as well as researches conducted at different spatial and temporal scales focused on the assessment and monitoring of the conservation status of habitats and target plant species, identification of new habitats and subtypes, and their diagnostic species.