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The present study provides a critical review of the available historical data on the distribution of Abies nebrodensis, a fir tree endemic to Sicily. The only (somewhat ambiguous) references to its occurrence on Mount Etna date back to the 1st century bc and refer back to the 3rd century bc. Although the botanical and forestry literature and the very few surviving herbarium specimens do not prove that A. nebrodensis grew outside the Madonie mountain range, several indications suggest its past occurrence on other Sicilian mountain ranges such as the Erei, Nebrodi, and probably also Sicani mountains. The results of the most recent pollen investigations (still ongoing) point to the disappearance of Abies from most of Sicily by the 1st century bc, and at least since the Middle Ages A. nebrodensis had become extremely rare even on the Madonie mountains. Publications focused on the wooden artefacts from archaeological excavations and the restoration of architectural heritage have provided some information on the past use of fir wood in Sicily, but the species identity of the firs being used remain unresolved. The present review of the past occurrence and distribution of A. nebrodensis suggests that it may have previously occupied a wider ecological niche.

We used 39 morphological and anatomical needle traits in the biometric comparisons Abies nebrodensis with A. alba and A. cephalonica. The multivariate analyses were utilised and a closer relationship of A. nebrodensis to A. cephalonica than to A. alba was detected, in contrast to what has been shown for cone characteristics.

Abies nebrodensis (Lojac.) Mattei (Pinaceae) is a species living in a very small population only in a confined area of Sicily. In this study, the dichloromethane extract of the leaves was analyzed. Apart from three already known metabolites namely dehydroabietic acid; maltol; and rheosmin, previously detected in other species of Abies, a lanostane derivative was isolated. Its chemical structure was elucidated by means of extensive spectroscopic methods.

Abies nebrodensis, endemic to the Madonie mountains (central-north Sicily), was originally described by Lojacono Pojero as A. pectinata var. nebrodensis and later raised to the rank of species. The species is considered to be critically endangered and was thought to be extinct until an extant population was rediscovered in 1957. The name is here lectotypified on a specimen preserved at NAP.

Abies nebrodensis (Lojac.) Mattei (Pinaceae) is a species occurring in a very small population only in a restricted area of Sicily. Its taxonomic classification as different species has been object of discussion. In this work the chemical composition of the essential oil from the leaves is presented for the first time and compared to the essential oils from other euroasiatic species reported in literature. Peculiar characteristics of the essential oil of A. nebrodensis are highlighted.

Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso- mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro- mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adapted Fagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

In this study Authors report scale insects (Hemiptera: Coccomorpha) species for the first time recorded on some endemic plants of Sicilian flora, namely, Abies nebrodensis Mattei (Pinaceae), Astragalus siculus Biv. (Leguminosae), Betula aetnensis Rafinesque (Betulaceae) and Zelkova sicula Di Pasquale Garfi & Quezel (Ulmaceae). Abie s nebrodensis is present in a single small population on Madonie Mountains. On this conifer the fir scale Parlatoria parlatoriae (Sulc) (Diaspididae) was collected. On B. aetnensis , that colonizes the lava substrates of Etna Volcano mainly at 1300–1900 m.a.s.l., a consistent population of an undescribed Diaspidiotus species (currently being described) was collected. Moreover Lepidosaphes ulmi (Linnaeus) (Diaspididae) was detected and collected on A. siculus which is characteristic plant of the upper part of the volcano. Zelkova sicula is a very rare relict of the Tertiary, belonging to a genus of plants already extinct in Continental Europe; with only two small populations living in restricted woodland areas in south oriental Sicily where two scale insects were collected: Aspidiotus nerii (Costa) (Diaspididae) and Parthenolecanium sp. (Coccidae).

RAPD technique using haploid DNA from megagametophyte tissue was applied to detect the pattern of genetic variation within Abies nebrodensis, a species endemic to Sicily. Results were compared with a reference system composed of representatives of five Mediterranean firs: A. alba, A. cephalonica, A. nordmanniana, A. numidica, and A. pinsapo. Diploid genotypes for RAPD loci were inferred from segregation patterns in haploid megagametophytes from individual trees. Therefore, it was possible to distinguish between homo- and heterozygotes carrying a RAPD fragment and to calculate unbiased estimates of genetic parameters. In the interspecific comparison, A. nebrodensis appears intermixed with the other Abies species, supporting the hypothesis of remarkable hybridization processes within the genus. A high level of polymorphism and deviation from panmictic equilibrium as a result of heterozygote excess depict a pattern of population structure in A. nebrodensis that agrees with the expectations for an outcrossing perennial species, in spite of its critical conditions. Implications with respect to the conservation management of the species are also discussed.

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A small and relict population of Silver Fir (Abies alba Miller) in the Apuan Alps (Tuscany - Italy) has been confirmed and immediately analyzed in order to evaluate its level of autochthony. Some 19th-20th century floristic evidence, along with an extraordinary 17th century cartographic document, testify to the presence of Silver Fir in the same place. Results obtained from chloroplast genome analysis have been compared with Alpine and Apennine population data in order to identify any genetic relationship. The phylogenetic tree obtained shows a strong affinity between the Apuan populations and those in the Apennines, confirming with the historical floristic documents the autochthony of the Apuan fir population. Conservation activities have consisted, in situ, in improving vegetation habitats, through thinning surrounding woods, which will allow natural regeneration. Ex situ, near the Forest Garden of Camporgiano (Lucca), saplings have been obtained from seeds of the autochthonous Silver Fir population; later, these were planted out close to the relict population, so constituting a new experimental conservation nucleus. Thus a new nature conservation activity for a relict habitat, of priority on the 92/43/CEE Directive (“Apennine beech forests with Abies alba and beech forests with Abies nebrodensis“), has been initiated.

A. nebrodensis (Nebrodi fir, Sicilian fir) is restricted to a small area of the Madonie Natural Park in Sicily. According to recent estimates, its only population consists of 30 adult individuals and a fluctuating number of juveniles derived from natural regeneration; besides, some hundreds of cultivated plants are preserved as ex situ collection. We used RAPD data from six 10-mer primers to examine the consequences of extensive historical clearance and human pressures on the extant population. Data from multiple life stages and different habitat conditions were considered, affording an opportunity to ascertain for the first time the structure of genetic variation in the extant uneven-aged population on both spatial and temporal scale. Consistent with previous works, we found that the history of disturbance and past land use did not affect drastically the biological diversity of the present-day population. Considerable levels of genetic variation were detected both in adult and juvenile sets. The non-significant correlation between genetic and physical distances (Mantel test; r = - 0.075) revealed a random distribution of genotypes in the natural stand. When the juvenile set was divided in 17 subsets, based on maternal provenance and growing conditions, Shannon's index (54%) and AMOVA analysis (84%) indicated that most of genetic variation resides within subsets. Neighbour-joining cluster analysis supported the hypothesis of high crossfertilization rates expected for a woody perennial species; nevertheless some grouping of related individuals suggested partial inbreeding and a weak pattern of genetic structure. Changes in structure can occur as the progeny ages and offspring thinning is responsible for moulding patterns of genetic diversity and population structure in time.

Abies nebrodensis (Lojac.) Mattei (Sicilian fir) is an endangered species represented by only one population of 29 adult individuals occurring in a limited area of the Madonie Range in northern Sicily (Italy). Taxonomic boundaries between this taxon and the neighboring Abies species are not clear. In this study, we used six chloroplast simple-sequence repeats (cpSSRs) to investigate the population genetic structure and the distribution of chloroplast haplotypic variation in A. nebrodensis and three of the neighboring Abies species: Abies alba (Mill.), Abies numidica (De Lann) and Abies cephalonica (Loud.). Our aims were to quantify the level of cpDNA differentiation within the Abies populations and to shed light on the history of A. nebrodensis. Diversity levels based on the haplotype frequency at six cpSSRs were high, especially in A. alba and A. cephalonica. In all, we found 122 haplotypes among the 169 individuals analyzed, and the four species were distinguished from each other by their haplotype composition. The majority of the haplotypes (76%) were detected only once, but in A. nebrodensis seven individuals (41% of the sample population) shared the same haplotype. Moreover, the seven A. nebrodensis individuals with an identical haplotype showed a tendency to be geographically grouped within the population's limited range. The analysis of molecular variance (AMOVA) showed a significant difference in the level of apportionment of gene diversity between the species A. alba and A. cephalonica (F-ST=0.191 and 0.012, respectively). AMOVA analysis conducted over all populations from the four species showed that 19% of the total cpSSR variation was attributable to differences among species, 6% was due to differences among populations within species, and 74% to differences within populations. The high percentage of unique haplotypes identified confirms the power of cpSSR haplotype analysis for identifying individual trees in individual Abies populations. Our results indicate that A. nebrodensis differs from the other three Abies species investigated and support its classification as an independent taxon. The results also showed a decreased level of variation in A. nebrodensis and suggested that the species has experienced a genetic bottleneck during the last two centuries. Accession Number: WOS:000168403700012

Allozyme, chloroplast (cpDNA) and random amplified polymorphic DNA (RAPD) markers have been used to estimate genetic and taxonomic relationships among different populations of Abies alba and the relic population of A. nebrodensis. Twelve isozyme gene loci, as well as restriction fragment length polymorphism (RFLP) at cpDNA spacer regions between t-RNA genes were analysed. Moreover, a set of 60 random sequence 10-mer primers were tested. Over all isozyme loci, evident differences in allele frequencies among A. nebrodensis and A. alba populations were found, particularly at 2 loci, phosphoglucose isomerase (Pgi-a) and shikimate dehydrogenase (Skd-a). More than 10% of the total genetic diversity was due to differences among populations. High values of genetic distances among populations were also found. Out of the 60 primers tested, 12 resulted in a polymorphic banding pattern both within and among populations. A total of 84 RAPD fragments were produced by the 12 selected primers. A phenogram of relationships among populations was constructed based on RAPD band sharing: the differentiation of the A. nebrodensis population was evident. The analysis of molecular variance (AMOVA) was used to apportion the variation among individuals within populations and among populations. There was considerable variation within each population: even so, genetic divergence was found among populations. This pattern of genetic variation was very different from that reported for inbred species. Identical cpDNA amplification and restriction patterns were observed among all the individuals sampled from the populations. Taken together, the results of allozyme and RAPDs show a clear differentiation among A. nebrodensis and A. alba populations and provide support for their classification into two different taxonomic groups.

This further contribution to the Palynological Italian Flora deals with eight entities of the Sicilian Flora, some of which are endemic of the Sicilian floristic sector and some of the Pelagic Maltese one. Palynological cards show pollen features observed by light and scanning electron microscopy. This actuopalynological work has connections with geobotanical researches carried out on the Madonie mountains (Sicily, Italy).

Anatomical studies were made on the structural and decorative elements of the wooden ceiling of the 12th century Cappella Palatina in Palermo, Sicily, to identify the timbers used, analyse their likely provenance, and discuss the selection criteria used by the builders. One hundred and fifty fragments were examined. Abies sp., Pinus sp., Betula sp., Populus sp. and Fagus sylvatica were found and all are most probably from Sicily. Some of the Abies fragments probably belong to Abies nebrodensis as they have exceptionally long tracheids, very tall rays, and abundant crystals. This species was over-Iogged in the past and now only 29 trees remain in the Madonie Natural Reserve in Sicily. Abies and Pinus are found in vertieal and horizontal painted panels, while Populus, Betula and Fagus were used in smaller parts of the muqarnas (painted niches). The choice of species seems to have been related to original tree size. The large size of the Abies boles meant that quarter sawn panels could be used. Sieilian Abies was highly valued at that time for its wood quality.Special attention was paid to the problem of distinguishing partly degraded Abies and Cedrus woods. However, the scalloped torus in some sampies displayed ambiguous features and these sampies were therefore classified as Abies/Cedrus.

Allozyme markers (1 1 loci, 32 alleles) have been used to estimate the genetic diversity within the unique surviving popu- lation of the relic species Abies nebrodensis. Results were analysed in comparison with a reference system composed of 16 Italian populations of A. alba and one representative provenance of A. cephalonica, A. equi-trojani, A. bornmuelleriana and A. nordmanni- ana. These investigations allowed us i) to show that alleles Idh-2a and Pgi-1a have contributed to the differentiation of the A. nebro- densis population from those of the reference system, ii) to show that the genetic diversity within A. nebrodensis is similar to that of dynamic silver fir populations growing in analogous isolation and progressive drifting situations, while, simultaneously, a very high excess of homozygotes is detected, iii) to identify in situ three different zones which corresponded to the diversity core of the species, one site in recolonizing phase and one site in an extinction phase. The origin of this particular situation is discussed and silvicultural interventions to relaunch the dynamics of the species are suggested. (© Inra/Elsevier, Paris.)