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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.

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).

2p.

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.

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.)

The final publication is availabe at/O documento está disponível em http://www.tuzvo.sk/files/fg/volumes/2001/FG08-2_119-127.pdf Submitted by Maria Eduarda Pereira Rodrigues (erodrigues@ipcb.pt) on 2011-05-24T15:12:04Z No. of bitstreams: 1 2001 Parducci FG.pdf: 78613 bytes, checksum: 97e8fd07f6858d235c47466352f92a1a (MD5) Approved for entry into archive by Maria Eduarda Pereira Rodrigues(erodrigues@ipcb.pt) on 2011-05-24T15:15:38Z (GMT) No. of bitstreams: 1 2001 Parducci FG.pdf: 78613 bytes, checksum: 97e8fd07f6858d235c47466352f92a1a (MD5) Made available in DSpace on 2011-05-24T15:16:19Z (GMT). No. of bitstreams: 1 2001 Parducci FG.pdf: 78613 bytes, checksum: 97e8fd07f6858d235c47466352f92a1a (MD5) Previous issue date: 2001