Search results for "syntaxonomy"
showing 10 items of 54 documents
Populetum pamiricae ass. nova – an endemic forest association to Pamir in Tajikistan (Middle Asia)
2015
Abstract The floristic structure, distribution and habitat requirements of a forest syntaxon, Populetum pamiricae ass. nova is described. The potential range of the Populetum pamiricae association comprises the mountains of eastern Tajikistan (Pamir Alai Mts), Kashgaria in western China (Kunlun Shan Mts) and north-eastern Afghanistan (Hindu Kush Mts) in Middle Asia. The biotope of this community comprises of high mountain river valleys situated at elevations between 2,500 and 3,200 m above sea level. Phytocoenoses of the Populetum pamiricae association are characterized by the apparent domination in the tree layer of a diagnostic species, Populus pamirica. The tree stand has a mean cover ar…
Downy-oak woods of Italy: phytogeographical remarks on a controversial taxonomic and ecologic issue
2014
The importance of downy oak as an integral component of the "submediterranean" woods has been underscored by many studies. Nevertheless, terms like "submediterranean" and "downy oak" are some of the most poorly understood concepts in European phytogeographic and taxonomic research. Downy oak is well known to be a problematic taxon. The name "Quercus pubescens" (= Q. humilis) combines populations characterized by increasing phenotypic and genomic polymorphisms along north-south gradients, which is explained as the result of a "founder effect" produced by a relatively fast post-glacial re-colonization of the northern areas through rare long-distance dispersal events. On the other hand, polymo…
Alnus glutinosa Riparian Woodlands of Italy and Corsica: Phytosociological Classification and Floristic Diversity
2022
A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished relevés, is presented. A total of 456 phytosociological relevés were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinos…
Contributo alla conoscenza della vegetazione forestale dell’Egeo.
2004
Nell'ambito di ricerche fitosociologiche nell'area egea vengono presentati i risultati relativi alle formazioni forestali attualmente osservabili nelle isole dell'Egeo meridionale. Questo tipo di vegetazione è stato in precedenza oggetto di studio da parte di vari autori, fra cui in particolare Krause et al. (1963), Zohary & Orshan (1966), Barbero & Quezel (1980), Costa et al. (1984) e Géhu et al. (1989, 1990, 1992), che hanno esaminato sotto il profilo fitosociologico alcune isole dell'Egeo quali Eubea, Creta, Rodi e Karpatos. Allo scopo di ampliare le conoscenze su quest'area del Mediterraneo, ancora poco nota dal punto di vista vegetazionale, sono state effettuate indagini su numerose is…
New insight on Mediterranean and sub-Mediterranean syntaxa included in the Vegetation Prodrome of Italy
2015
Pseudosteppes and related grassland vegetation in the Pamir-Alai and western Tian Shan Mts – the borderland of the Irano-Turanian and Euro-Siberian r…
2020
The aim of our study was to complete the syntaxonomical scheme for grassland vegetation of the lowland, montane and alpine zones in the Pamir-Alai and western Tian Shan Mts in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. A total of 198 relevés were sampled in 2013–2018 using the seven-degree cover-abundance scale of the Braun-Blanquet approach. They were classified with k-means algorithm with tranforming cover values to three level scale of the following intervals 0%, 5% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. Non-metric Multidimensional Scaling (NMDS)…
Halophytic vegetation and adjoining plant communities in Middle Asia (Pamir-Alai and western Tian Shan)
2021
In this paper, we complete the syntaxonomical scheme for halophytic vegetation and adjoining plant communities of the lowland, montane and alpine zones in the Pamir-Alai and western Tian Shan in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. A total of 217 relevés were sampled in 2014–2019 using the seven-degree cover-abundance scale of the Braun-Blanquet approach. Modified TWlNSPAN was used to classify plant communities based on species composition. The cover-abundance scale was transformed using the four-step interval scale with cut-off levels at 0%, 5% and 25%. Diagnostic species were identified using the phi coefficient as a fidelity measure. Non-metric Mul…
Vegetation of rock crevices of the montane and colline zones in the Pamir-Alai and Tian Shan Mts in Tajikistan (Middle Asia)
2014
The paper presents the results of phytosociological research conducted on the vegetation of rock habitats in the montane and colline zones of the Pamir-Alai Mountains (Tajikistan). During field surveys done in 2010–2013, 122 phytosociological releves were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. The vegetation studies were carried out generally in the western Pamir-Alai and south-western Tian Shan Mts, especially in the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan, Turkestan, Kuramin and Vanch ranges. A synopsis of the rock communities of the montane and colline zones in Tajikistan is proposed. The collected material presents most of the …
A syntaxonomical survey of the Sicilian dwarf shrub vegetation belonging to the class Rumici-Astragaletea siculi
2005
Basing on literature data and unpublished relevés from Sicily, a survey of the syntaxa belonging to the class Rumici-Astragaletea siculi Pignatti & Nimis 1980 em. Mucina 1997 (= Cerastio-Carlinetea nebrodensis Brullo 1984) is presented. The class groups orophilous plant communities dominated by dwarf- shrubs, often with a pulvinate and thorny growth form. The class is represented in Sicily by two orders: Rumici-Astragaletalia siculi Pignatti & Nimis 1980, including the sole alliance Rumici-Astragalion siculi Poli 1965, restricted to Mount Aetna, and Erysimo-Jurinetalia bocconei Brullo 1984, including two alliances: the acidophilous Armerion nebrodensis Brullo 1984 and the basiphilous Cerast…
Vegetation of rock clefts and ledges in the Pamir Alai Mts, Tajikistan (Middle Asia)
2014
AbstractThe paper presents the results of phytosociological research conducted on the vegetation of rock clefts and ledges in the Pamir-Alai Mountains (Tajikistan, Middle Asia). During the field studies, done in 2010–2012, 101 phytosociological relevés were taken. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. Communities of calcareous rock clefts and ledges with small soil amounts from several ranges (Zeravshan Mts, Hissar Mts, Hazratishokh Mts, Darvaz Mts, Rushan Mts and Vanch Mts), inhabiting mainly the alpine and subnival zone, have been described. A synopsis of the rock communities of the Pamir-Alai is proposed. In the examined vegetation plots 77 va…