Stazioni Eterotopiche di Saxifraga Incrustata Vest. nel Carso Triestino

Abstract

Two abnormal stands of SAXIFRAGA INCRUSTATA Vest, on the Karst of Trieste. — Near of Trieste there are two dolines (sinkholes), where Saxifraga incrustata occurs. The average height of the zone is 300 m above the sea. This unusual presence of a subalpine plant at so low altitude is to relate to a temperature's decrease owing to a very intensive evaporation. In summer time develops a draft between the opposite sides of the dolines and produces the strong evaporation of percolation water in one case and of the imbibition water of a thick moss layer at the other hand.     

Chasmophytes on screes? A rule and not an exception in the vegetation of the Karst (southwest Slovenia)

Abstract

We investigated the community ecology and autecology of chasmophytes in the Karst (southwest Slovenia). An unusually massive occurrence of chasmophytes on settled screes and rock falls was detected in some of the collapse dolines of ?kocjan Caves and surroundings, building floristically and physiognomically homogenous plant communities. At first sight, no significant floristic distinctions in vascular plants were observed between scree and rock crevice stands, despite striking differences in habitats. A detailed floristic survey of stands, including vascular plants and bryophytes, as well as ecological parameters, revealed four distinct vegetation types. Floristically, bryophytes proved to differentiate groups of stands excellently but, in contrast to vascular plants, their presence and abundance only poorly reflected site conditions. Among chasmophytes, which, in terms of the Braun-Blanquet approach in phytosociology, are assigned to the class Asplenietea trichomanes (sensu Braun-Blanquet and Oberdorfer), only Saxifraga petraea and Saxifraga tridactylites prefer rock crevices and artificial walls, respectively, while others, e.g., Saxifraga crustata, Primula auricula and Athamanta turbith, prefer screes and their habitat selection is governed by different ecological parameters, shaped primarily by the phenomenon of temperature inversion in collapse dolines.     

The Chrysopogono grylli-Nerietum oleandri association in Croatia as compared with other Rubo ulmifolii-Nerion oleandri communities (Tamaricetalia,Nerio-Tamaricetea) in the Mediterranean

Abstract

A new association, Chrysopogono grylli-Nerietum oleandri, situated in the south of Croatia, is proposed. According to its floristic structure, physiognomy and ecology, it belongs to the Rubo ulmifolii-Nerion oleandri alliance (Tamaricetalia, Nerio-Tamaricetea). It is the only association with Nerium oleander in Croatia. This community has developed along a temporary watercourse as a vegetation exclave (extrazonal stand) within the climazonal evergreen forest vegetation of the Oleo-Ceratonion alliance. The association has a thermophilous character and a large number of companions from the Quercetalia ilicis and Scorzonero-Chrysopogonetalia communities. This report compares the floristic composition of this association with others of the Rubo ulmifolii-Nerion oleandri alliance from other Mediterranean areas. The Croatian association is most similar to the Spartio-Nerietum oleandri association from the Ionian side of Calabria (south Italy). The syntaxonomic status of the Montenegrin association Andropogono distachyi-Nerietum oleandri was determined, and the status of the stands with Nerium oleander is discussed.     

Delimitation of the alliances Caricion firmae (Seslerietalia albicantis) and Seslerion juncifoliae (Seslerietalia juncifoliae) in the southeastern Alps and Dinaric mountains

Abstract

A syntaxonomic and phytogeographic delimitation of the calcareous open sedge swards in the alpine belt of the Alps (Caricion firmae) and subalpine and alpine tussock grasslands in wind-exposed habitats (Seslerion juncifoliae) in the area of the south-eastern Alps and of the Dinaric mountains was performed. Analyses based on hierarchical classification, ordination and chorology clearly showed the distinction between the syntaxa: stands from the Liburnian karst (Mt Sne?nik – SW. Slovenia, Mts Risnjak and Snje?nik – NW. Croatia), Li?ka Plje?ivica and the Velebit mountains belong to the Dinaric alliance Seslerion juncifoliae, whereas stands from the Trnovski gozd plateau (W. Slovenia, north-westernmost part of the Dinaric mountains), although somewhat transitional between the two alliances, and stands from the Alps, were classified in the alliance Caricion firmae. The alliance Seslerion juncifoliae of the Dinaric mountains vicariates Caricion firmae of the Alps.     

Vegetation change in Southeast Greenland? Tasiilaq revisited after 40 years

Questions: Are there changes in species composition of the oceanic, Low‐Arctic tundra vegetation after 40 years? Can possible changes be attributed to climate change? Location: Ammassalik Island near Tasiilaq, Southeast Greenland. Methods: Species composition and cover of 11 key vegetation types were recorded in 110 vegetation survey plots in 1968–1969 and in 11 permanent plots in 1981. Recording was repeated in 2007. Temporal changes in species composition and cover between the surveys were tested using permutation tests linked with constrained ordinations for vegetation types, and Mann–Whitney tests for individual species. Changes in vegetation were related to climate change. Results: Although climate became warmer over the studied period, most of the vegetation types showed minor changes. The changes were most conspicuous in mire and snowbed vegetation, such as the Carex rariflora mire and Hylocomium splendens snowbed. In the C. rariflora mire, species number and cover of vascular plants and cover of bryophytes increased, whereas in the H. splendens snowbed species numbers of vascular plants, bryophytes, and also lichens increased. Lichen richness increased in the Carex bigelowii snowbed and cover of bryophytes in the Salix herbacea snowbed. No such changes occurred in the Alchemilla glomerulans meadow, Alchemilla alpina snowbed and Phyllodoce coerulea heath. There was no change of species composition within the Salix glauca scrub, A. alpina snowbed, lichen grassland and the Empetrum nigrum and Phyllodoce coerulea heaths. Most changes resulted from increasing frequency or cover of some species; there were very few decreasing species. Most of the increasing species indicate drier substrate conditions. Conclusions: Only minor changes in species composition and cover were detected in the vegetation types studied. These changes were probably caused by milder winters and warmer summers during the years before the 2007 sampling. Climate warming may have reduced the duration of snow cover and soil moisture, particularly in snowbed and mire habitats, where species composition change was most pronounced. However, its magnitude was insufficient to cause a major change in species composition. Thus, on the level of plant community types, tundra vegetation near Tasiilaq was rather stable over the last 40 years.     

Composition and ecology of the Quercus coccifera L. communities along the eastern Adriatic coast (NE Mediterranean)

The aim of this study is to classify and describe all plant communities with Quercus coccifera covering the entire eastern Adriatic coast and islands from north Croatia to south Albania, and to relate their species composition, chorotypes and life forms to environmental factors using Pignatti ecological indicator values. From total 70 phytosociological relevés, we identified and described four floristically and ecologically distinctive vegetation communities (two new proposed subassociations, one association and stand each) using TWINSPAN and the Braun-Blanquet classification scheme. In Croatia and Montenegro, Q. coccifera is forming macchia within the Fraxino orni–Quercetum cocciferae pistacietosum lentisci. Quercus coccifera occurs only sparsely in south Croatia as a shrubland within Fraxino orni–Quercetum cocciferae nerietosum oleandri subassociation or macchia within the Erico arboreae–Arbutetum unedonis association. Despite the difference in biogeographic position and bioclimates, low shrubby Albanian Q. coccifera stands are more closely related to the Q. coccifera communities from the western Mediterranean. Eastern Adriatic communities appear exclusively within the Querceta ilicis vegetation zone and spread within the meso-Mediterranean belt. They nevertheless are an important part of the region's natural heritage and management plans must ensure that all forms of land are used in a sustainable way.     

Snowbed vegetation of far northeastern Asia

Abstract. Two main types of snowbed habitat with their typical vegetation in far NE Asia are described. In extreme snowbeds, snow depth is ≥ 5 m; the vegetation is sparse and characterized by Salix polaris and arctic and arctic-alpine taxa adapted to a very short growing season. In moderately snowrich habitats, with a snow depth of 1.5 — 5 m, the environment is more favourable for plant growth as compared to both extreme snow-rich and mesic habitats, because of snow protection in winter, little permafrost, high organic matter accumulation, and no major reduction of the growing season. Within each snowbed habitat there are two series of community types for lime-rich and lime-poor habitats. Along with a large number of pH-amphitolerant species including the dominants Salix polaris, Cassiope tetragona, Artemisia tilesii which occur in both habitat types, acidic sites usually also have stenoacidophytes (Carex nesophila, Loiseleuria procumbens), and hemiacidophytes (Salix chamissonis, Artemisia arctica). Differential taxa of circumneutral and basic soils are the stenobasiphytes Salix rotundifolia and Dendranthema integrifolium and the hemibasiphytes Salix reticulata and Carex scirpoidea. Ten Chukotka snowbed associations are provisionally described and a diagnostic table is presented according to the Braun-Blanquet approach. The syntaxonomy and evolution of Beringian snowbed vegetation are discussed.     

Effects of nutrient amendments on modular growth,flowering effort and reproduction of snowbed plants

Background: There have been few studies on the effects on alpine flora and vegetation of an increase in nutrient availability. Two main potential sources of increased nutrient availability in alpine ecosystems are enhanced mineralisation caused by climate warming and atmospheric nitrogen deposition. Little is known on how life history traits of different species are related at individual and community levels to enhanced nutrient availability.

Aims: We investigated the effects of nitrogen and phosphorus addition on the modular growth, flowering and germination of four species: two snowbed specialists and two alpine generalists.

Methods: We established in a late snowbed at the Gavia Pass, Italian Alps, a factorial experiment with four fertiliser treatments (N, P, Low N+P, and High N+P) and an unfertilised control. Nutrients were applied in 2003–2006 and we recorded the number of modules per individuals, total number of flowers, number of flowers per flowering module, and calculated the percentage of flowering modules in 2005 and 2006, and counted the number of seedlings in 2006.

Results: The modular growth and flowering effort of the species appeared to be co-limited by N and P. The alpine generalists showed greater responses to fertilization in vegetative growth and flowering compared with snowbed specialists. The number of seedlings recorded indicated species-specific responses to nutrient addition.

Conclusions: Our results suggest that enhanced nutrient availability stimulates modular growth and flowering effort in responsive alpine generalist species. This, in turn, could lead to an increase in their abundance, leading to changes in community structure in snowbeds with enhanced nutrient availability.     

Frammenti di Quereeto a Roverella e di Macchia Mediterranea a Vivara (Isole Flegree)

Abstract

Fragments of oak-crop with QUERCUS PUBESCENS willd. and of mediterranean maquis in the isle of vivara (Flegrean isles). — In these note the types of arboreous and shrubby vegetation pointed out in the islet of Vivara are passed in rapid review. Particular references to the types of vegetation arranged in the Quercion ilicis are given.

A short account is reserved to the presence of Quercus pubescens Willd. and to the importance of these species concerning the construction of the fragments of oak-crop and of mediterranean high maquis that are present to the edges of tableland and on the sides of the smallest Flegrean isles.

It is a question of unusual aspects of vegetation for a microinsular environment. Therefore they are worthy of study before they are destroyed or still more altered.     

Residui di Leccete pure e miste sulla Murgia di Putignano

Summary

Purpose of this paper is to point out the residues of Quercus Ilex woods in the hilly region of Murgia di Putignano (Puglia) which lies inside the distribution area of Q. trojana, now the main wood-forming tree-species of this territory.

Fourteen different small Q. Ilex stands are mentioned, as marked on alleged map. One of them (n° 1 on the map) has been more carefully studied through a whole year, and all plants growing in it have been collected.     

I piani di vegetazione in Italia

Abstract

Vertical zonation of vegetation in Italy. – A revision of the scientific terms used by Italian botanists for the vertical zonation of vegetation reveals some inconsistencies and allows to propose an alignement with the nomenclature used in English and proposed already during the International Botanical Congress of 1910: Belt (ital.: fascia) for the topographical zonation and zone (ital.: zona) for the geographical zonation. Italy belongs to two zones: the mediterranean and the medioeuropean one. A scheme of vegetation belts in both of the zones is proposed. The indications subalpine and montane are substituted by boreal and subatlantic.     

Production of Perennial Vegetation in an Oasis-desert Transition Zone in NW China - Allometric Estimation,and Assessment of Flooding and Use Effects

River oases at the southern fringe of the Taklamakan desert in NW China are surrounded by belts of spontaneous vegetation that protect the oases from sand drift. As an important source of forage, fuel and construction wood, this foreland vegetation is also a component part of the agricultural system of the oases but has been, and still is, destroyed through overuse. Within a broader study that aimed to provide a basis for a sustainable management of this foreland vegetation, biomass and production were studied in four vegetation types dominated either by Alhagi sparsifolia, Calligonum caput-medusae, Populus euphratica, or Tamarix ramosissima that were thought to occur under different regimes of natural flooding in the foreland of Qira (Cele) oasis, Xinjiang, NW China. Shoot biomass components were closely correlated to basal area (Calligonum, Populus, Tamarix) or shrub volume and projection area (Alhagi), enabling non-destructive estimation of stand biomass from shoot diameters or shrub dimensions with sufficient precision using allometric regression equations. Relationships between shoot basal area and biomass of the woody species (Calligonum, Populus and Tamarix) agreed with predictions by a theoretical model of plant vascular systems, suggesting that they are determined by hydraulic and mechanical requirements for shoot architecture. Average aboveground biomass densities of typical stands in late summer were 2.97 Mg/ha in Alhagi, 3.6 Mg/ha in a row plantation and 10.9 Mg/ha in homogenous stands of Calligonum, 22–29 Mg/ha in 22 year-old Populus forests and 1.9–3.1 Mg/ha in Tamarix-dominated vegetation. Annual aboveground production including wood and assimilation organs ranged from 2.11 to 11.3 Mg/ha in plantations of Calligonum, 3.17 to 6.12 Mg/ha in Populus, and 1.55 to 1.74 Mg/ha (based on total ground area) or 3.10 to 7.15 Mg/ha (in homogenous stands) in Tamarix. Production of Alhagi is equal to peak biomass. A thinning treatment simulating use by the local population enhanced productivity of Calligonum, Populus and Tamarix. A complete harvest of Alhagi in late August decreased production in the following year. An artificial flood irrigation treatment did not sufficiently increase soil water content except in the uppermost layer and had no clear beneficial effect on growth of the four species and even a negative effect on Alhagi, which was due to increased competition from annual species. As biomass and production with or without artificial irrigation were much higher than values expected for rain-fed desert vegetation at a mean annual precipitation of 35 mm, it is concluded that the existence of all vegetation types studied is probably based on permanent access to groundwater and that natural floods or precipitation do not contribute to their water supply. The effects of agricultural groundwater use in the oasis on groundwater in the foreland of the oasis need further study. Sustainable use of this productive vegetation is possible but requires proper management.     

Syntaxonomy of Arundo stands along the eastern Adriatic coast

Based on the diagnostic morphological characters of the Arundo taxa, and after both field and herbarium observation, three species (A. micrantha, A. plinii and A. donax) were found along the eastern Adriatic coast. Altogether, 50 phytocoenological relevés from Arundo stands were collected in Croatia, Montenegro and Albania between 2010 and 2013. Three associations with a predominance of Arundo species were determined: Arundinetum plinianae, Arundinetum micranthae and Arundini donacis–Convolvuletum sepium. Among them, Arundinetum micranthae is described and proposed as a new association, belonging to the Artemisietea vulgaris class. It occurs frequently along the coastal belt between the cities of Split and Dubrovnik in South Croatia. The syntaxonomy of the associations is discussed and comparison with similar communities from Italy is made. The vegetation and floristic structure of the associations is discussed as a potential basis for biodiversity conservation programmes and for evaluating the state of these ecosystems in the future.     

Lineamenti della vegetazione lucana

Abstract

The vegetation of Lucania: an outline. – The vegetation of Lucania is outlined on the basis of the existing literature and of personal observations. After a short review of the botanical literature a new subdivision of this region is proposed taking into consideration both geological and botanical criteria. The various plant formations are described, among them: the vegetation of the sandy beaches along the Ionian Sea; the Policoro Forest on the coastal plain; the Lygeum spartum stands on the clays; the Quercus cents forests, and the Fagus silvatica ones (comprising the two associations Aquifolio-Fagetum and Asyneumati-Fagetum); the relict Abies alba stands; the summit prairies; the Pinus leucodermis stands.     

Phytosociological survey of the tundra vegetation of the Kola Peninsula,Russia

Abstract. A phytosociological survey of the tundra vegetation of the Kola Peninsula, Russia according to the Braun-Blanquet approach is presented. The areas examined comprise the treeless zones along the shores of the White Sea and the Barents Sea as well as mountain areas above the timberline. Plant communities were assigned to five alliances: Loiseleurio-Diapension on dry, wind-swept habitats on summits and wind-eroded sites in the lowland; Phyllodoco-Vaccinion myrtilli on well-drained soils with intermediate snow cover and moisture status, mostly in the lowlands and lower belts of mountain tundra; Nardo-Caricion bigelowii comprising early snowbed and Salicion herbaceae late snowbed communities; Adenostylion alliariae comprising mesophilous tall-herb communities along mountain springs and in wind-protected and well-drained sites near the sea shore. A DCA-ordination showed that two major gradients determine the varation in tundra vegetation, altitude and topography, which are connected to variation in snow cover. The syntaxa described are well-differentiated, although they form a syntaxonomical continuum.     

Hosts and distribution of Viscum album L. ssp. album in Croatia and Slovenia

Abstract

Viscum album L. ssp. album is semi-parasitic on deciduous trees and shrubs. In order to identify hosts and map the distribution of V. album ssp. album in Croatia and Slovenia, field research was carried out, and herbaria were surveyed. In Croatia and Slovenia, V. album ssp. album occurred on 59 taxa. In Croatia, there were 52 hosts (33 autochthonous and 15 allochthonous species, two cultivars and two hybrids). In Slovenia, there were 25 hosts (21 autochthonous and four allochthonous species). There were 18 hosts common to both countries, 34 hosts were found only in Croatia, and seven hosts only in Slovenia. The hosts belonged to 13 families. The majority of these (19 species) belong to the Rosaceae, followed by Salicaceae, Aceraceae, Betulaceae, Fagaceae, Juglandaceae, Tiliaceae, Hippocastanaceae, Ulmaceae, Oleaceae, Fabaceae, Moraceae and Viscaceae. All hosts have been previously recorded in the literature, except Alnus japonica (Thunb.) Steud., Amelanchier lamarckii F.G. Schroed. and Crataegus nigra Waldst. et Kit. The distribution of this mistletoe was scattered, due to the scattered distribution of hosts, local conditions, movement of bird-vectors, etc. A continuous distribution was found only in part of the distribution area of narrow-leaved ash (Fraxinus angustifolia Vahl).     

Microfunghi del suolo di aree floristicamente omogenee di tre cenosi boschive delle Prealpi bellunesi

Abstract

Soil microfungi in homogeneous areas of three plant communities of North Italy.—The soil microfungi associated with three different community types in Prealpine region of North Italy were investigated. Frequency values for the taxonomic entities isolated were calculated, based on occurrence at sampling sites, in each community. Most of the entities were quantitatively rare. The microfungal communities associated with Acer pseudoplatanus and Fraxinus excelsior, with Ostrya carpinifolia and with Fagus sylvatica appeared to be a distinctive group, even if many of them contained a substantial number of species wich are common with other vegetation types.     

Benthic macroinvertebrates associated with four species of macrophytes

Benthic macroinvertebrates associated with four species of macrophytes (Nymphoides peltata, Ceratophyllum demersum, Polygonum amphibium and Carex sp.) were investigated during two growing seasons (2001 and 2002) in the slow-flowing Čonakut Channel in the Kopački rit Nature Park in Croatia. A total of 31 macroinvertebrate taxa were found. C. demersum, a submerged plant with dissected leaves, supported the highest macroinvertebrate abundance, almost seven times more than N. peltata, a floating plant with undissected leaves, which harboured the lowest abundance during the research period. Chironomidae larvae (50–83%) and Oligochaeta (14–46%) were the most abundant groups recorded on all macrophyte species. Water-level fluctuation, because of its influence on the appearance and growth of aquatic vegetation, and the trophic state of water within the macrophyte stands seemed to be the main factors which affected the taxonomic composition and abundance of macroinvertebrates.     

Population dynamics of Gentiana pneumonanthe and Rhynchospora fusca during wet heathland restoration

Abstract. The population dynamics and reproductive strategies of two rare wet heathland species, Gentiana pneumonanthe and Rhynchospora, were studied in experimental permanent plots in a wet heathland near Bremen, NW Germany, to assess how effective sod cutting and mowing are in promoting these species. In one experiment, small plots (0.25 m² - 4 m²) were sod-cut or mown; in the second, one large plot 30 mx 50m) was sod-cut. The development of the vegetation and the number of shoots of the two target species were recorded annually. Sod cutting lead to the highest shoot numbers of Gentiana in the long run, whilst mowing was more effective at the beginning of the experiment. Seedlings and adult shoots slowly became more and more abundant after sod cutting. In contrast, Rhynchospora soon formed closed stands after sod-cutting, first through seed germination and then through fast clonal growth of the established individuals. Moist soil or short inundations promoted the germination and seedling establishment of Gentiana, whereas drought negatively affected seedling recruitment. Long periods of inundation severely reduced the population at first, but high numbers of seedlings were found in the following growing season. For the disturbance-dependent Gentiana and Rhynchospora, the availability of gaps within the vegetation is of crucial importance. To promote existing populations, we suggest small-scale sod cuttings which create gaps without disturbing existing flowering individuals too much. For degenerated stands of wet heathland we recommend large-scale sod cutting to activate the seed bank. Additionally, seed introduction may be helpful to encourage the development of a wet heathland with characteristic floristic composition.