Nicola Alessi - Academia.edu (original) (raw)
Papers by Nicola Alessi
The coenology of the beech forests in Italy has been extensively investigated by classic phytosoc... more The coenology of the beech forests in Italy has been extensively investigated by classic phytosociology. However this valuable effort produced a huge amount of syntaxonomical units, displaying complex patterns of cross-similarities in the hierarchy, which hardly match the limited stand variability observed in the field. Besides this, most of the basic studies have been traditionally focused on the local scale, due to the unavailability of larger archives of sample-plots. Hitherto, this lack hindered any consistent approach to a comprehensive typological classification of the zonal Fagus dominated or Fagus mixed forest belts in Italy. Here we present some preliminary results of a coenological overview of late successional beech forest stands, applying a formal classification approach to all available data for Italy appeared to date in the phytosociological literature. The data have been extracted from the EU-IT-011 "Georeferenced Vegetation Database of Sapienza University of Rom...
Aims of this research group are the establishment and participation to a federated database of It... more Aims of this research group are the establishment and participation to a federated database of Italian vegetation. This is done in order to evaluate the “real existence” of plant communities dominated by Quercus sp.pl. and Fagus sylvatica, investigate about how these communities are distinguished on the base of macroecological factors and/or floristic composition. An attempt to parameterize these units in order to verify their biogeographical robustness and adaptation to current classifications in EU (EUNIS, Corine Biotopes classification) for the Mediterranean region is here proposed. From a wide database of published and certified phytosociological relevés of broadleaved deciduous submediterranean and temperate deciduous forests, about 3500 relevés have been selected. The vegetation plots corresponds to the communities at the level of association ranked into the class of Querco-Fagetea, specifically dominated by oaks and beech, recorded in the territories south of the watershed of...
From an initial database of 1539 relevés with 1199 species, covering the whole distribution of Q.... more From an initial database of 1539 relevés with 1199 species, covering the whole distribution of Q. suber in Europe, we obtained a subset of 1270 samples with 1171 species after resampling. -Cluster analysis and Twinspan classification showed similar results for 5 clusters, which were relatively well interpreted in their geogrpahic distribution and species composition. -Maxent distribution models were computed with the results of hierarchichal clustering, producing meaninful models of habitat suitability for the community types.
Biodiversity & Ecology, 2012
In recent years, interest in availability of georeferenced vegetation plots has stimulated or rei... more In recent years, interest in availability of georeferenced vegetation plots has stimulated or reinvigorated national initiatives to compile these data. In Italy, eleven vegetation databases are currently registered in the Global Index of Vegetation-Plot Databases (GIVD). In this paper we describe the Vegetation Plot Database-Sapi-enza University of Rome (VPD-Sapienza; GIVD code EU-IT-011), which started in 2012 and rapidly became one of the most prominent ones with a total of 21,917 georeferenced vegetation plots spanning across the country. These plots include 286,650 vascular plant species occurrences. Most of the plots belong to temperate deciduous forests (Querco roboris-Fagetea sylvaticae) and broadleaved evergreen forests (Quercetea ilicis), which together account for about 40% of the database. The need for the establishment of a national federated database integrating other national, regional, local and thematic databases is discussed in order to avoid setbacks such as duplication of data, taxonomic and syntaxonomic inconsistencies, and reduced efficiencies in collabora-tive projects, both at national and international levels. Abbreviations: GIVD = Global Index of Vegetation-Plot Databases; VPD-Sapienza = Vegetation Plot Database – Sapienza University of Rome.
From a data base of the Italian phytosociological relevés of the Italian vegetation under ongoing... more From a data base of the Italian phytosociological relevés of the Italian vegetation under ongoing development, the sample plots of oak forests in the peninsular regions of Italy and neighboring islands have been extracted and their distribution has been examined. This archive is basically aimed to the parameterization of phytosociological units in order to verify their ecological and biogeographical robustness. At present the data base stores 70% of the existing sources in literature. The selected material corresponds to the communities at the level of association ranked into the orders of Querceta specifically dominated by oaks, recorded in the territories south of the watershed of Northern Apennines (peninsular Italy): Quercetalia ilicis, Quercetalia calliprini, Quercetalia pubescenti-petraeae, Quercetalia robori-petraeae. The dataset used in this study is based on the sample plots identified as representative for different associations, described up to now in the certified botani...
The conservation of habitat types has been recognized to be of relevant importance for the conser... more The conservation of habitat types has been recognized to be of relevant importance for the conservation of biodiversity and is a major concern in the European Union. With the 92/43/EEC Habitats Directive, the European Commission targeted these habitat types, which conservation must be ensured by Member States. In this context, the Habitat type 9330 " Quercus suber forests " is intended to ensure the conservation of cork oak woodlands in Europe. To support the enhancement of nature conservation policies, in this study we provide a classification of cork oak woodlands in Europe using a large vegetation database. We identify four major groups with clear biogeographic differences and characterize them by lists of indicator species. We also provide distribution maps based on occurrence data and the modelled potential area of distribution as an additional tool for conservation. This study offers a contribution to the comparative description of the European Q. suber woodlands subtypes and to establish a protocol for habitat monitoring and assessment.
The coenology of the beech forests in Italy has been extensively investigated by classic phytosoc... more The coenology of the beech forests in Italy has been extensively investigated by classic phytosociology. However this valuable effort produced a huge amount of syntaxonomical units, displaying complex patterns of cross-similarities in the hierarchy, which hardly match the limited stand variability observed in the field. Besides this, most of the basic studies have been traditionally focused on the local scale, due to the unavailability of larger archives of sample-plots. Hitherto, this lack hindered any consistent approach to a comprehensive typological classification of the zonal Fagus dominated or Fagus mixed forest belts in Italy. Here we present some preliminary results of a coenological overview of late successional beech forest stands, applying a formal classification approach to all available data for Italy appeared to date in the phytosociological literature. The data have been extracted from the EU-IT-011 "Georeferenced Vegetation Database of Sapienza University of Rom...
Aims of this research group are the establishment and participation to a federated database of It... more Aims of this research group are the establishment and participation to a federated database of Italian vegetation. This is done in order to evaluate the “real existence” of plant communities dominated by Quercus sp.pl. and Fagus sylvatica, investigate about how these communities are distinguished on the base of macroecological factors and/or floristic composition. An attempt to parameterize these units in order to verify their biogeographical robustness and adaptation to current classifications in EU (EUNIS, Corine Biotopes classification) for the Mediterranean region is here proposed. From a wide database of published and certified phytosociological relevés of broadleaved deciduous submediterranean and temperate deciduous forests, about 3500 relevés have been selected. The vegetation plots corresponds to the communities at the level of association ranked into the class of Querco-Fagetea, specifically dominated by oaks and beech, recorded in the territories south of the watershed of...
From an initial database of 1539 relevés with 1199 species, covering the whole distribution of Q.... more From an initial database of 1539 relevés with 1199 species, covering the whole distribution of Q. suber in Europe, we obtained a subset of 1270 samples with 1171 species after resampling. -Cluster analysis and Twinspan classification showed similar results for 5 clusters, which were relatively well interpreted in their geogrpahic distribution and species composition. -Maxent distribution models were computed with the results of hierarchichal clustering, producing meaninful models of habitat suitability for the community types.
Biodiversity & Ecology, 2012
In recent years, interest in availability of georeferenced vegetation plots has stimulated or rei... more In recent years, interest in availability of georeferenced vegetation plots has stimulated or reinvigorated national initiatives to compile these data. In Italy, eleven vegetation databases are currently registered in the Global Index of Vegetation-Plot Databases (GIVD). In this paper we describe the Vegetation Plot Database-Sapi-enza University of Rome (VPD-Sapienza; GIVD code EU-IT-011), which started in 2012 and rapidly became one of the most prominent ones with a total of 21,917 georeferenced vegetation plots spanning across the country. These plots include 286,650 vascular plant species occurrences. Most of the plots belong to temperate deciduous forests (Querco roboris-Fagetea sylvaticae) and broadleaved evergreen forests (Quercetea ilicis), which together account for about 40% of the database. The need for the establishment of a national federated database integrating other national, regional, local and thematic databases is discussed in order to avoid setbacks such as duplication of data, taxonomic and syntaxonomic inconsistencies, and reduced efficiencies in collabora-tive projects, both at national and international levels. Abbreviations: GIVD = Global Index of Vegetation-Plot Databases; VPD-Sapienza = Vegetation Plot Database – Sapienza University of Rome.
From a data base of the Italian phytosociological relevés of the Italian vegetation under ongoing... more From a data base of the Italian phytosociological relevés of the Italian vegetation under ongoing development, the sample plots of oak forests in the peninsular regions of Italy and neighboring islands have been extracted and their distribution has been examined. This archive is basically aimed to the parameterization of phytosociological units in order to verify their ecological and biogeographical robustness. At present the data base stores 70% of the existing sources in literature. The selected material corresponds to the communities at the level of association ranked into the orders of Querceta specifically dominated by oaks, recorded in the territories south of the watershed of Northern Apennines (peninsular Italy): Quercetalia ilicis, Quercetalia calliprini, Quercetalia pubescenti-petraeae, Quercetalia robori-petraeae. The dataset used in this study is based on the sample plots identified as representative for different associations, described up to now in the certified botani...
The conservation of habitat types has been recognized to be of relevant importance for the conser... more The conservation of habitat types has been recognized to be of relevant importance for the conservation of biodiversity and is a major concern in the European Union. With the 92/43/EEC Habitats Directive, the European Commission targeted these habitat types, which conservation must be ensured by Member States. In this context, the Habitat type 9330 " Quercus suber forests " is intended to ensure the conservation of cork oak woodlands in Europe. To support the enhancement of nature conservation policies, in this study we provide a classification of cork oak woodlands in Europe using a large vegetation database. We identify four major groups with clear biogeographic differences and characterize them by lists of indicator species. We also provide distribution maps based on occurrence data and the modelled potential area of distribution as an additional tool for conservation. This study offers a contribution to the comparative description of the European Q. suber woodlands subtypes and to establish a protocol for habitat monitoring and assessment.