75 research outputs found
Does residence time affect responses of alien species richness to environmental and spatial processes?
One of the most robust emerging generalisations in invasion biology is that the probability of invasion increases with the time since introduction (residence time). We analysed the spatial distribution of alien vascular plant species in a region of north-eastern Italy to understand the influence of residence time on patterns of alien species richness. Neophytes were grouped according to three periods of arrival in the study region (1500–1800, 1800–1900, and > 1900). We applied multiple regression (spatial and nonspatial) with hierarchical partitioning to determine the influence of climate and human pressure on species richness within the groups. We also applied variation partitioning to evaluate the relative importance of environmental and spatial processes. Temperature mainly influenced groups with species having a longer residence time, while human pressure influenced the more recently introduced species, although its influence remained significant in all groups. Partial regression analyses showed that most of the variation explained by the models is attributable to spatially structured environmental variation, while environment and space had small independent effects. However, effects independent of environment decreased, and spatially independent effects increased, from older to the more recent neophytes. Our data illustrate that the distribution of alien species richness for species that arrived recently is related to propagule pressure, availability of novel niches created by human activity, and neutral-based (dispersal limitation) processes, while climate filtering plays a key role in the distribution of species that arrived earlier. This study highlights the importance of residence time, spatial structure, and environmental conditions in the patterns of alien species richness and for a better understanding of its geographical variation
KritiÄŤke primjedbe o srodnosti vrsta Euphorbia saxatilis-triflora-kerneri
Na temelju revizije herbarskog materijala i vlastitih terenskih istraĹľivanja autor dolazi do zakljuÄŤka da vrsta Euphorbia saxatilis najvjerojatnije ne dolazi u Jugoslaviji. Svi navodi koje je autor provjerio odnose se na srodnu vrstu Euphorbia triflora.
Euphorbia triflora može se prema autoru raščlaniti na dvije podvrste: subsp. triflora rasprostranjena na području ilirskog krša i subsp. kemeri (Hüter) L. Poldini comb. nov. na venecijansko-friulskom području
Aspects of vineyard vegetation in Northeastern Italy and eastern neighbouring territories: Cerastio tenoreani-Geranietum dissecti and Mercurialetum annuae as archaic, disappearing coenosis
Abstract
Recent original data concerning vineyard spring vegetation from Veneto hilly belt (North-eastern Italy) highlighted once again the phytogeographic originality of south-eastern territories with respect to Central European ones, also in anthropogenic coenosis. New relevés suggested to restate the association Cerastio tenoreani-Geranietum dissecti as vicarious vegetation of Geranio rotundifolii-Allietum vinealis occurring on the north side of the Alps. The comparison of autumn material from terracing vineyards of the sandy-marly Eocene flysch around Trieste coast with similar European relevés enabled to reject the not validly described Anagallido-Mercurialetum and to replace it with Mercurialetum annuae. In modern winegrowing Cerastio-Geranietum and Mercurialetum annuae are vanishing due to changing of agronomic schemes, as some relevés reported in the text document
Aspects of vineyard vegetation in Northeastern Italy and eastern neighbouring territories: Cerastio tenoreani-Geranietum dissecti and Mercurialetum annui as archaic, disappearing coenosis
Recent original data concerning vineyard spring vegetation from Veneto hilly belt (Northeastern Italy) highligthed once again the phytogeographic originality of southeastern territories with respect to Central European ones, also in anthropogenic coenosis. New relevés suggested to restate the association Cerastio tenoreani-Geranietum dissecti as vicarious vegetation of Geranio rotundifolii-Allietum vinealis occurring on the north side of the Alps. The comparison of autumn material from terracing vineyards of the sandy-marly Eocene flysch around Trieste coast with similar European relevés enabled to reject the not validly described Anagallido-Mercurialetum and to replace it with Mercurialetum annuae. In modern winegrowing Cerastio-Geranietum and Mercurialetum annuae are vanishing due to changing of agronomic schemes, as some relevés reported in the text document
Alpine grasslands with dominant Luzula alpinopilosa in the Julian and Carnic Alps (NW Slovenia, NE Italy)
Abstract
We conducted a phytosociological study of alpine grasslands with dominant Luzula alpinopilosa in the Julian and Carnic Alps. Based on a comparison with similar communities elsewhere in the Alps we described a new association Junco jacquinii-Luzuletum alpinopilosae, which we classify into the provisional alliance Doronico glacialis-Juncion jacquinii, order Festucetalia spadiceae and class Juncetea trifidi. The new association characterises moist shady grasslands in gullies and on ledges on limestone admixed with marlstone and chert, in the elevation range between 2000 and 2500 m, where the snow cover persists for extended periods. We distinguish three subassociations: -galietosum anisophyllae (the most calcareous form), -potentilletosum aureae (typical form) and -leucanthemopsietosum alpinae (acidophilic form on Werfen sandstones in the Carnic Alps, which is the most similar to the stands of the association Luzuletum alpinopilosae from the Central Alps)
Alpine grasslands with dominant Luzula alpinopilosa in the Julian and Carnic Alps (NW Slovenia, NE Italy)
We conducted a phytosociological study into alpine grasslands with dominant Luzula alpinopilosa in the Julian and Carnic Alps. Based on a comparison with similar communities elsewhere in the Alps we described a new association Junco jacquinii-Luzuletum alpinopilosae, which we classify into the provisional alliance Doronico glacialis-Juncion jacquinii, order Festucetalia spadiceae and class Juncetea trifidi. The new association characterises moist shady grasslands in gullies and on ledges on limestone admixed with marlstone and chert, in the elevation range between 2,000 and 2,500 m, where the snow cover persists for extended periods. We distinguish three subassociations: -galietosum anisophyllae (the most calcareous form), -potentilletosum aureae (typical form) and                 -leucanthemopsietosum alpinae (acidophilous form on Werfen sandstones in the Carnic Alps, which is the most similar to the stands of the association Luzuletum alpinopilosae from the Central Alps)
Phytosociological analysis of noble hardwood forests (Ostryo-Tilienion platyphylli) in the Karst and its neighbouring regions (SW Slovenia)
In SW Slovenia, at Gora under Ĺ˝elezna Vrata and Petnik gorge near Branik – both on the northern edge of the Karst, in the collapse doline Orleška Draga at SeĹľana and under Brkinski Rob at the contact of the Karst and Brkini Hills, we conducted a phytosociological analysis of the stands whose tree layer is dominated by Tilia platyphyllos, T. cordata, Acer pseudoplatanus, Ulmus glabra, in places also Carpinus betulus and Ostrya carpinifolia, and classified them into three associations, Corydalido ochroleucae-Aceretum pseudoplatani, Paeonio officinalis-Tilietum platyphylli and Fraxino orni-Aceretum pseudoplatani. The latter was described as a new. Also new is a secondary large-leaved lime association Lamio orvalae-Tilietum platyphylli on the sites of montane beech forests (Lamio orvalae-Fagetum) in the ÄŚepovan valley, at the contact of the Dinaric and sub-Mediterranean phytogeographical regions of Slovenia.  
A New Scotch Pine Association onAalluvial Deposits of the Southeastern Alps
Es wird eine neue Assoziation im Bereich vom Orno- Ericion Horvat 59 mit dem Namen Aino incanae-Pinetum sylvestris aus den SO-Alpen beschrieben. Sie bestockt die Flussschotterbänke vom Save-Tal übers Tagliamento bis zum Piave-Tal. Die Assoziations-Differenzial-Arten sind Nässe- und Feuchtezeiger. Die neue Assoziation zerfällt in eine Vorderalpen- und in eine Inneralpen-Rasse. Es wird auch die Typisierung einiger aus Piemonte (W-Italien) stammenden Aufnahmen (Mondino 1963) als Calamagrostio pseudophragmitae-Pinetum sylvestris vorgenommen.Opisana je nova asocijacija Alno incanae-Pinetum sylvestris iz sveze Orno-Ericion Horvat 59 s područja jugoistočnih Alpa. Rasprostranjena je na šljunkovitim prudovima od doline Save preko Taljamenta do doline Piave. Diferencijalne vrste asocijacije indikatori su velike vlažnosti tla. Asocijacija je raščlanjena u dvije geografske varijante.
Autor također predlaže, na temelju vegetacijskih snimaka Mondina (1963), da se borove šume u području Piemonta (zapadna Italija) označe imenom Calamagrostio pseudophragmitae-Pinetum sylvestris.A new association, Alno incanae-Pinetum sylvestris, belonging to the Alliance Orno-Ericion Horvat 59, is described from the Southeastern Alps. The association colonizes alluvial deposits in the area extending between the rivers Sava and Piave. Its differential species are indicators of soil moisture. The new association is subdivided into two geographical races: one occurring in the outer, the other in the inner parts of the Alps.
A group of relevés from Piemonte (Mondino 1963) is typified with the name Calamagrostio pseudophragmitae-Pinetum sylvestris
La vegetazione forestale e prativa su Flysch lungo ii Golfo di Trieste
Es wird eine Waldassoziation, das Seslerio-Quercetum petraeae beschrieben, das die Hügel aus Eozänflysch am Triester Golf bewächst. Es handelt sich um einen massig azidophilen Wald, der eine schwankende Stellung zwischen den Assoziationen Ostryo-Carpinion orientalis und denjenigen von Quercion roboris-petraeae einnimmt. Seine systematische Stellung wird noch offen gelassen. Der Kahlschlag führt über ein kurzdauerndes Heide-Stadium mit Calluna und Cistus salviifolius, das durch die Betonung des Mediterrancharakters ausgezeichnet ist, zur Weidewiese Chrysopogoni-Onobrychidetum tommasinii. Man bemerkt dabei eine fortschreitende Entsäuerung des Bodens.Autor opisuje novu šumsku zajednicu — Seslerio-Quercetum petraeae — koja obrašćuje brežuljke Tršćanskog zaljeva izgrađene od eocenskog fliša. Ova umjereno acidofilna asocijacija zauzima prelazni položaj između asocijacija sveze Ostryo-Carpinion orientalis i sveze Quercion roboris-petraeae, a pitanje njezina mjesta u fitocenološkom sistemu još nije riješeno. Kao posljedica sječe na golo pojavljuje se kratkotrajni stadij vrištine s vrstama Calluna i Cistus salviifolius, koji se odlikuje po svom mediteranskom značaju, a razvija se dalje u pašnjačko-livadnu zajednicu Chrysopogoni-Onobrychidetum tommasinii. Paralelno s tim razvojem napreduje i raskiseljavanje tla.Viene descritta un’associazione foréstale, il Seslerio-Quercetum petraeae, che si sviluppa sulle colline di Flysch eocenico al margine del Golfo di Trieste. Si tratta di un bosco mediocremente acidofilo che occupa una posi- zione oscillante fra le cenosi dell\u27Ostryo-Carpinion orientalis e quelle del Quercion roboris-petraeae. La sua posizione sistemática rimane perciö im- pregiudicata. La distruzione totale di questo bosco porta ad uno stadio transitorio di landa, caratterizzato da Calluna e Cistus salviifolius, con accentu- azione del carattere mediterráneo, e piú oltre, al prato-pascolo che è stato chiamato Chrysopogoni-Onobrychidetum tommasinii. Paralelamente a questa degradazione si nota una progressiva deacidificazione del suolo
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