A phytosociological analysis of abandoned terraced olive grove shrublands in the Tyrrhenian district of Central Italy

ABSTRACT

A phytosociological study of the shrubland communities which colonise abandoned terraced olive groves in the Tyrrhenian district of Central Italy is presented here. The vegetational analysis was carried out using the Braun Blanquet phytosociological approach. Two main types of shrubland communities characterising distinct environmental conditions occur within abandoned terraced olive groves. On the one hand, there are those scrub types which tend to occupy the central part of the terrace; on the other hand, there are the scrubs types which develop along the stone walls bordering the terrace. Different phytosociological associations, sub-associations, and variants ranging from Pistacio-Rhamnetalia alaternii to Prunetalia spinosae are recognised and described. In the warm dry areas, both Myrto-Lentiscetum and Rhamno-Euphorbietum dendroidis occur. Also, a new Oleo-Ceratonion sub-association (Myrto-Lentiscetum spartietosum junceii) is presented here for the first time. In the inner zones of the study area, a range of aspects characterising a new Pruno-Rubion ulmifolii community type (Roso-Rubetum ulmifolii ass. nova) are identified.     

High elevation coniferous vegetation of Guatemala

A phytosociological study of the juniper (locally called huito), pine (locally called sacch), pine-alder and fir forests of the Sierra de los Cuchumatanes and Cadena Volcánica in Guatemala was carried out. The Zürich-Montpellier approach was followed. In total 119 relevés were sampled and the data were organised in phytosociological tables to distinguish vegetation clusters. TWINSPAN was used to evaluate major differences among plant communities. Seven zonal plant communities were distinguished and described, namely: (1)Relbunium microphyllum-Agrostis tolucensis, (2)Werneria nubigena-Agrostis exserta, (3)Lachemilla vulcanica-Pinus hartwegii, (4)Holodiscus argenteus-Pinus hartwegii, (5)Hypnum cypressiforme-Juniperus standleyi, (6)Agave hurteri-Alnus firmifolia and (7)Sabazia pinetorum-Abies guatemalensis. This paper provides a thorough floristic characterisation of each community and outlines the major anthropogenic activities. To conclude, ecologic and floristic (dis)similarities between plant communities of the study area and those of Central Mexico, like the different altitudinal distribution of fir forests and the establishment of mid-successional communities such as theAgave hurteri-Alnus firmifolia were discussed.     

Correlation between macrophyte vegetation and some water properties in the irrigation system of the Lower river Po Plane

Abstract

The distribution of macrophytic plant communities, defined by phytosociological numerical methods, in the irrigation system of the Lower river Po Plane was correlated with water characteristich. Water samples were collected periodically within phytocoena well-characterized from the phytosociological viewpoint. Nymphaeid-dominated communities (all. Nymphaeion) usually occur in deeper waters than elodeid- myriophyllid-, and ceratophyllid-dominated vegetation types (all. Potamogetonion). Hydrochemically, all of the studied waterbodies can be classified as rich in electrolytes and in bicarbonates. The distribution of phytocoena reflects a gradient in nutrient content: the Nymphoidetum peltatae characterizes waters moderately rich; the Myriophyllum spicatum community and the Trapetum natantis fairly rich; the Potamogetonetum pectinati and the Ceratophyllum demersum community very rich in nutrients.     

Nuovi micromiceti su Pandanacee

Abstract

Helianthemetea guttati communities are pioneer spring and early summer ephemeral grasslands, dominated by non-nitrophilous therophytes. In Continental Portugal, these communities have not yet been fully investigated, and thus the objectives of the present study are: (1) to identify community types in therophytic grasslands; (2) to recognize those communities that configure the European priority habitat 6220* (pseudo-steppe with grasses and annuals); (3) to establish environmental gradients underlying their spatial variation; (4) to assess how floristic composition is affected by land use factors. Vegetation sampling using phytosociological methodology was carried out on 80 grasslands. Modified Twinspan classification and canonical correspondence analysis (CCA) was applied for the classification and ordination of relevés whereas partial CCA (pCCA) and variation partitioning were used to assess the relative influence of individual land use factors. Some 270 species were identified across 11 community types whose floristic patterns were mainly explained by environmental gradients related to altitude and soil type while land use variables could only explain a small part of the floristic variation. Based on biogeography and the determination of diagnostic species, four phytosociological new associations and a new subassociation are proposed: Holco-Brachypodietum distachyi, Holco-Micropyretum tenellae, Micropyro-Anthoxanthetum aristati and Leontodonto-Vulpietum bromoidis vulpietosum membranaceae.     

Vegetation of the aquatic and marshland habitats in the Orava region,including the first records of <Emphasis Type="Italic">Potametum alpini,Potametum zizii</Emphasis> and <Emphasis Type="Italic">Ranunculo-Juncetum bulbosi</Emphasis> in the territory of Slovakia

The vegetation of the aquatic and marshland habitats of the Orava region (north of Slovakia) was studied in 2009, using traditional phytosociological methods. Sixteen aquatic and eighteen marsh plant communities were described within 96 phytosociological relevés by using TWINSPAN with the application of the dominance principle. Three associations, Potametum alpini, Potametum zizii and Ranunculo-Juncetum bulbosi, were found as new communities for Slovakia. Myriophylletum verticillati, Potametum nodosi, Potametum graminei and Alisma gramineum community were recorded in the northernmost localities in Slovakia. Among marsh communities, Calletum palustris is very rare, both in the Orava region and in Slovakia as a whole. According to Ellenberg’s indicator values (EIV), moisture was evaluated as the main ecological gradient. Plant communities are ordered along the first Detrended Correspodence Analysis (DCA) axis in a typical hydroseries (Potametea → Lemnetea → Phragmition communis → Phalaridion arundinaceae, Oenanthion aquaticae and Sparganio-Glycerion → Magnocaricion elatae). The second DCA axis was most correlated with EIV for nutrients. Among the five directly measured ecological characteristics (temperature, pH and conductivity of water, water depth, and substrate type), conductivity of water (0.44, P < 0.01) and substrate type (0.32, P < 0.05) were the statistically significant variables explaining the variability along the first DCA axis.     

Maquis vegetation in the eastern Cantabrian coastal fringe

Abstract. The typology and distribution are discussed of hitherto poorly known Mediterranean-type maquis vegetation from the eastern stretch of the coastal fringe of the Cantabrian Mountains. 51 phytosociological relevés of maquis with Arbutus unedo (‘madroñales’) and Quercus coccifera (kermes oak shrubland or ‘coscojares’) were submitted to Correspondence Analysis and table rearrangement. The results are discussed and interpreted in the light of actual biogeographical and palaeohistorical knowledge. A sharp division between (uniform) acidophilous and (diversified) basophilous communities was revealed. On the basis of the phytosociological classification four new syntaxa are described: the associations Ulici gallii-Arbutetum unedonis, Phillyreo latifoliae-Arbutetum unedonis - with two subassociations: arbutetosum unedonis and viburnetosum tini - and the association Genisto occidentalis-Quercetum cocciferae.     

Geographic variation among Iberian communities of the exotic halophyte Cotula coronopifolia

The exotic annual forb Cotula coronopifolia has locally invaded salt marsh communities naturally dominated by Spergularia marina along large parts of the Iberian coastline. While the floristic composition of C. coronopifolia dominated communities on the Atlantic coast of northern Portugal has already been described, this information was missing for the southern part of the country. We carried out a phytosociological study at 21 sites along the south-western and southern coast of mainland Portugal to determine the ecology and syntaxonomical status of these communities, and to compare them to the Atlantic ones. Plant communities co-dominated by C. coronopifolia and S. marina were generally found in the sub-halophilous inner part of salt marshes. They occupied gaps within taller perennial vegetation (Juncus maritimus formations), such as small pools temporarily inundated with brackish waters. Southern communities differed from the northern ones by the high abundance of Triglochin barrelieri and the absence of salt-intolerant species that are present in the Atlantic communities. This difference may result from the drier summer climate in southern regions, leading to intense water evaporation and thus, more saline conditions. We propose to classify the Mediterranean communities in a new association, the Cotulo coronopifoliae–Triglochinetum barrelieri. High abundance of Limonium diffusum further allowed the distinction of a new subassociation limonietosum diffusi for the southernmost part of Portugal. Results show that invasive exotic plants can form new phytosociological associations with a characteristic species composition, but that these community types, despite being dominated by the same invader, still show ecological and geographical differentiation.     

The power of potential natural vegetation (and of spatial‐temporal scale): a response to Carrión & Fernández (2009)

A commentary by Carrión & Fernández (Journal of Biogeography, 2009, 36 , 2202–2203) compared Holocene pollen records with models of potential natural vegetation (PNV) proposed in the phytosociological literature and concluded that the predicted PNV resulted from anthropogenic disturbance. However, the authors misinterpreted PNV, leading to two serious flaws in their assumptions: (1) PNV is not defined as a pre‐anthropic or climax plant community; and (2) PNV is not a concept restricted to the phytosociological method. Therefore we criticize the conclusions expressed in the commentary, and we stress the need for an interdisciplinary approach based on multi‐temporal and multi‐spatial scales to achieve a modern framework for the study of plant communities.     

Mediterranean hay meadow communities: diversity and dynamics in mountain areas throughout the Iberian Central Range (Spain)

This paper reports a phytosociological study on managed hay meadow communities in the main mountains of the Spanish Central Range. Multivariate techniques (Cluster analysis and CA-ordination) were applied in the classification of the relevés and ordination of vegetation units and species. Clusters were related to the following associations: Agrostio castellanae–Arrhenatheretum bulbosi, Festuco amplae–Cynosuretum cristati, and F. amplae–Agrostietum castellanae. The scattergram suggested that the dynamic patterns between communities are associated with soil nutrient content and moisture. We propose a new subassociation: F. amplae–A. castellanae gaudinietosum fragilis that includes Salmantincensean Agrostis castellana communities growing in regions with lower supramediterranean thermotype.     

Plant Communities in Multi-Metal Contaminated Soils: A Case Study in the National Park of Alta Murgia (Apulia Region - Southern Italy)

A phytosociological study was conducted in the National Park of Alta Murgia in the Apulia region (Southern Italy) to determine the adverse effects of metal contamination of soils on the distribution of plant communities. The phytosociological analyses have shown a remarkable biodiversity of vegetation on non-contaminated soils, while biodiversity appeared strongly reduced on metal-contaminated soils. The area is naturally covered by a wide steppic grassland dominated by Stipa austroitalica Martinovský subsp. austroitalica. Brassicaceae such as Sinapis arvensis L. are the dominating species on moderated contaminated soils, whereas spiny species of Asteraceae such as Silybum marianum (L.) Gaertn. and Carduus pycnocephalus L. subsp. pycnocephalus are the dominating vegetation on heavily metal-contaminated soils. The presence of these spontaneous species on contaminated soils suggest their potential for restoration of degraded lands by phytostabilization strategy.     

Pre-climax epiphyte communities of bryophytes and lichens in Mediterranean forests from the Central Plateau (Spain)

The pre-climax epiphytic communities of forests from the Spanish Mediterranean region (Central Plateau) were studied by numerical and traditional floristic methods. One hundred phytosociological relevés were analyzed through a classical numerical approach based on hard partitions improved by PCoA — Principal Coordinates Analysis — ordinations. Two groups easily related to two different suballiances included in Frullanion dilatatae Lecointe 1975, Ulotenion crispae (Barkman 1958) Lecointe 1975 and Fabronienion pusillae Barkman 1958 were detected. Two new syntaxa within the ass. Ortotrichetum lyellii (Allorge 1922) Lecointe 1975 are proposed. Phytogeography, syntaxonomy and ecology of these communities are discussed.     

Numerical phytosociology of the subalpine belt of the Kazbegi region,Caucasus, USSR

A vegetational transect across a glacial valley was investigated. Structure and species composition, as well as influence of disturbance by biotic factors (grazing of sheep and cattle) and abiotic factors (topography, wind, water) are discussed.According to species composition and community structure, 4 main vegetation types were distinguished by comparing field data from phytosociological relevés with results of numerical treatments (3 methods of numerical classification and DCA ordination): 1) Chamaesciadium acaule-Polygonum viviparum, 2) Festuca cf. woronowii-Carex tristis, 3) Veratrum lobelianum-Taraxacum stevenii and 4) Rhododendron caucasicum-Vaccinium myrtillus communities.Species diversity (evenness, and number of species) was low in the ungrazed dwarf-shrub alpine communities, which were dominated by Rhododendron caucasicum, in comparison with the grazed meadow. The highest values of these characteristics were found in the transitions among the types.     

Syntaxonomy and chorology of the Vaccinium myrtillus communities in the Monti Reatini (Central Italy)

Abstract

The present paper details the results of a phytosociological study on Vaccinium myrtillus communities in the Monti Reatini (Central Apennines). A comparison is reported with Vaccinium communities from the rest of the Italian peninsula (already described), showing the coenological and syntaxonomical autonomy of the Monti Reatini types. The Authors include the Monti Reatini shrublands with V. myrtillus and Juniperus nana in the Pino-Juniperetea class and secondary vegetation forms dynamically linked to them in two new Poo violaceae-Nardetum subassociations: Poo violaceae-Nardetum brachypodietosum rupestris and Poo violaceae-Nardetum caricetosum kitaibelianae.     

Community patterns on exposed cliffs in a Mediterranean calcareous mountain

The main focus of this paper is to establish the community diversity pattern of vegetation in exposed-cliffs in the Mediterranean region and the relative importance of some environmental factors. Consequently, a study of a calcareous mesa in C-N Spain has been carried on, based on constrained ordination — CCA. The spatial scale approach for sampling was the patch on the cliff. The total number of taxa was 117 and the average per patch was 15. It is remarkable that the highest frequency plants are not rock specialists (chasmophytes), but generalist nanophanerophytes and chamaephytes.A community pattern has been detected and related to the geomorphology and lithology of the cliff-nine communities. However, those patches of the vertical areas are very heterogeneous in number of taxa and size. Nevertheless, the community pools seem constant for each vertical cliff zone. Based on the ordination results and linear models, this variability may be interpreted as different succession stages of a cyclic process. The primary colonization of the bare rock by chasmophytes leads to the accumulation of soil because of the biological activity and the stock-trampling ability of these specialist plants. After that, the patches may be invaded by generalist chamaephytes (Festuco-Poetalia) and later even by several nanophanerophytes (Sideritido-Salvion lavandulifoliae and Berberidion vulgaris). The root activity of these plants in combination with other erosive events can return the system to the beginning.A second objective included in the paper was related to the capacity of phytosociological approach, widely used in the Mediterranean region, to describe this type of community pattern. The surveyed mountain had previously studied in phytosociological terms. These relevés were compared through an assignation procedure — see text — to our community pattern. Both approaches seem to agree with high correspondence, but there are some differences that must be pointed out. They are related to the fact that spatial/ ecological heterogeneity does not always agree with the idealized phytosociological vegetation models, where only chasmophytic elements are considered.Abbreviations DCA = detrended correspondence analysis - CCA = canonical correspondence analysis     

The influence of <Emphasis Type="Italic">Ceratophyllum demersum</Emphasis> L. and <Emphasis Type="Italic">Stratiotes aloides</Emphasis> L. on richness and diversity of aquatic vegetation in the lakes of mid-eastern Poland

The aim of this study was to estimate the influence of Ceratophyllum demersum L. and Stratiotes aloides L. on the species richness and phytocoenotic diversity of aquatic vegetation in lakes. The study was based on field investigations in the Łęczna-Włodawa Lake District located in mid-eastern Poland. The studied lakes (32) included both polymictic and dimictic reservoirs. Both in the polymictic and dimictic lakes, statistically significant correlation coefficients were obtained between the parameters that characterize Stratiotes aloides (the frequency in the phytosociological relevés, the percent share of Stratiotetum aloidis association in the phytolittoral) and those characteristic for species richness (the total number of hydromacrophytes, the number of charophytes, elodeids, nymphaeids and lemnids), phytocoenotic richness (the mean number of species in the phytosociological relevés) and phytocoenotic diversity (the Shannon–Wiener Index). The communities with a share of S. aloides are characterized by higher species richness. However, not a single case of statistically significant dependency was reported between the parameters that describe C. demersum (the frequency in the phytosociological relevés, the percent share Ceratophylletum demersi association in the phytolittoral) and the vegetation traits in both lake groups. Common occurrence of Stratiotes aloides might be considered to be evidence for good status of an aquatic ecosystem and a very good indicator of species richness and diversity of aquatic vegetation.     

Vegetation of trampled soil dominated by C4 plants in Europe

Abstract. Plant communities of trampled soil dominated by plants characterized by the C4-assimilation syndrome were investigated in Europe. These species, belonging to genera such as Chamaesyce, Amaranthus, Eleusine, Eragrostis and Setaria, are thermophilous, late-germinating, prostrate herbs or grasses. The centre of their distribution is in the (Sub)Tropics. A syntaxonomic revision of the phytosociological material from Europe (incl. the Macaronesian Archipelago) revealed three alliances: the Euphorbion prostratae from Spain, the Polycarpo-Eleusinion indicae from Italy, and Slovenian and Croatian Istria, and the Eragrostio-Polygonion arenastri from temperate regions of Europe. The latter two syntaxa are described as new. All three alliances belong to the order Eragrostietalia (class Stellarietea mediae). Vicarious (ecologically analogous) communities occur also in southern Africa, eastern Asia and North America. The communities studied in the present paper are considered to be an impoverished form of highly diversified trampled plant communities typical of (sub)tropical areas.     

The Quercus petraea-dominated communities in Italy: Floristic,coenological and chorological diversity in an European perspective

In Italy, woods dominated by Quercus petraea are well documented within local and regional phytosociological studies but a critical revision of their principal ecological-floristic components based on a comprehensive Italian data set was missing. We gathered 209 published and unpublished Italian phytosociological relevés, where Q. petraea was dominant, that were investigated by means of multivariate analysis. The ecological requirements of the resulting groups were indirectly calculated by means of Ellenberg indicator value, and a chorological analysis was performed. The fidelity coefficient (phi) for the diagnostic species of each group was calculated. According to our analysis, five different types of Q. petraea woods were found to be present in Italy. Each group was characterized by means of its floristic, ecological and chorological components. These resulting five groups were further compared with similar Q. petraea-dominated woods recorded in other European locations, as to the floristic and chorological components. We collected 57 synoptic tables of Q. petraea communities coming from all over Europe. This data set, together with the Italian relevés, was submitted to exploratory multivariate analysis using also the chorological information. According to these analyses, the Italian woods dominated by Q. petraea can be subdivided in two main clusters: the communities belonging to It-1 group (Alps) fell within the central European communities, distinguished by the predominance of large distribution and European chorotypes. All the other Italian groups of relevés resulted to be positioned in the cluster which includes central southern, central eastern and eastern European Q. petraea communities. From the syntaxonomical point of view, the results of this analysis allow to attribute the Italian Q. petraea woods to seven alliances of three different orders. The ecological similarities between Erythronio-Quercion petraeae and Erythronio-Carpinion betuli are highlighted and the distribution of Erythronio-Quercion petraeae is limited to northern Apennines, in particular, to slopes facing the Po Valley.     

Patterned fens in Scotland: evidence from vegetation and water chemistry

Mires with attributes similar to the patterned fens of boreal continental regions have recently been reported from northern Scotland. This paper reports on the vegetation and water chemistry of 18 of these sites. Most of the 18 mires displayed remarkable uniformity in their vegetation, with Carex lasiocarpa being a main character species. Major variation of plant communities is associated with microtopographical niches, similar to those found on ombrotrophic mire systems and secondarily with pH and conductivity of surface waters. Nine vegetation noda are described and compared with existing phytosociological associations and National Vegetation Classification (NVC) communities. The dominant Sphagnum - Carex communities are intermediate between the Oxycocco-Sphagnetea and the Caricion lasiocarpae and are thus difficult to assign to existing associations or to NVC communities. Although there is a large variation in pH of surface waters (3.9–6.6), mean measurements for terrestrial and aquatic communities are 5.12 and 5.51 respectively. pH levels are comparable with poor fen systems elsewhere in Britain and slightly higher than patterned fens in continental regions of Europe and North America. The vegeta-tional and chemical attributes of these sites therefore confirm the existence of true patterned fen systems in the British Isles.     

Plant communities structure and composition in three coastal wetlands in southern Apulia (Italy)

In this paper the results of a study on the composition and the distribution of the plant communities in three coastal areas of southern Apulia are presented. A total of about 180 vegetation relevés were performed following the Braun-Blanquet phytosociological method. Vegetation data were analysed using both classification (UPGMA, similarity ratio) and ordination methods (including Non-metric Multidimensional Scaling (NMS) and Detrended Correspondence Analysis (DCA). The relevés are distributed in the following classes: Molinio-Arrhenateretea, Phragmito-Magnocaricetea, Juncetea maritimi, Sarcocornietea fruticosae, Saginetea maritimae, Thero-Salicornietea, Helianthemetea guttati. Detailed information about structure and zoning of the detected plant communities are here provided. Two new associations, belonging to the Alkanno-Maresion nanae alliance (microphytic ephemeral plant communities growing on sandy soils, Helianthemetea guttati class) have been described here, both in the “Torre Guaceto” site. The area of “Le Cesine” showed the highest total number of plant communities, while the “Saline di Punta della Contessa” site revealed the largest number of Sarcocornietea fruticosae plant communities.