DE GRUYTER
OPEN
HACQUETIA 14/2 • 2015, 265-276
DOI: 10.1515/hacq-2015-0005
PHYTOSOCIOLOGY AND ECOLOGY OF CRESSA CREtICA L. (CONVOLVULACEAE) ON THE EASTERN ADRIATIC COAST
Nenad JASPRICA^*, Milenko MILOVIČ2 & Marija ROMIC^
Abstract
The present phytosociological study of the eastern Adriatic coastal salt-marsh at Blato, Croatia, is based on the Braun-Blanquet approach. Five plant associations were recorded in the area: Juncetum maritimo-acuti, Puc-cinelliofestuciformis-Sarcocornietumfruticosae, Scirpetum maritimi, Enteromorpho intestinalidis-Ruppietum maritimae and Cressetum creticae. The association Cressetum creticae was found for the first time in Croatia as well as on the eastern Adriatic coast. This therophytic and halo-nitrophilous association shows a monospecific or paucispe-cific character and occupies the most haline and the driest parts of the salt-marsh. The association develops during the summer on silty clay substrates with organic matter derived from the decay of plants of the neighboring communities. According to key soil factor analysis no differences of grain size of the soils among the associations were found, while regarding electrical conductivity, Cl- and Na+ concentrations were higher in the Cressetum creticae than in any of the others associations. The particular original features of the site regarding its flora and vegetation would justify some measures of protection and management.
Key words: halophytic vegetation, soil analysis, Thero-Suaedetea splendentis, syntaxonomy, Croatia, central Adriatic, NE Mediterranean.
Izvleček
Predstavljamo fitocenološko raziskavo obalnega slanega mokrišča Blato (Hrvaška) v vzhodnem Jadranu, ki smo jo naredili po Braun-Blanquetovi metodi. V raziskovanem območju smo zabeležili pet asociacij: Juncetum maritimo-acuti, Puccinellio festuciformis-Sarcocornietum fruticosae, Scirpetum maritimi, Enteromorpho intestinalidis--Ruppietum maritimae in Cressetum creticae. Asociacija Cressetum cretice je na ozemlju Hrvaške in tudi na vzhodni obali Jadranskega morja opisana prvič. Terofitska in halo-nitrofilna asociacija je monospecifična ima siromašno vrstno sestavo in se pojavlja na najbolj slanih in suhih delih slanišča. Sestoji se razvijajo poleti na glineni podlagi z organsko snovjo, ki jo sestavljajo odmrli rastlinski deli s sosednjih združb. Analiza tal je pokazala, da med asociacijami ni bilo razlik v velikosti talnih delcev, električni konduktivnosti, koncentraciji Cl- in Na+ ionov pa sta bili v asociaciji Cressetum creticae višji kot ostalih asociacijah. Zaradi posebnosti v flori in vegetaciji bi bilo potrebno na preučevanem območju zagotoviti določene mere zaščite in ustrezen način upravljanja. Ključne besede: halofitska vegetacija, analize tal, Thero-Suaedetea splendentis, sintaksonomija, Hrvaška, srednji Jadran, SV Mediteran.
1. INTRODUCTION	and staging of birds. In the Adriatic salt-marsh
vegetation occurs mostly on the western and Coastal salt-marshes are distributed throughout northern coasts, the east coast being generally the Mediterranean area (Gehu 1999). In addition rocky (Pandža et al. 2007). to hosting some very rare plant species and com- Considerable research has been done on the munities, they are important areas for the nesting halophyte vegetation along the western Adriatic
1	Institute for Marine and Coastal Research, University of Dubrovnik, P.O. Box 83, HR-20000 Dubrovnik, Croatia. * Corresponding author: nenad.jasprica@unidu.hr
2	"Antun Vrančic" Grammar School, Put Gimnazije 64, HR-22000 Šibenik, Croatia
3	University of Zagreb, Faculty of Agriculture, Svetošimunska 25, HR-10000 Zagreb, Croatia
(cf. Poldini et al. 1999, Merloni 2007, Tomaselli et al. 2011, Sciandrello & Tomaselli 2014, and references therein) and eastern Adriatic coasts (Jankovic & Stevanovic 1983, Alegro et al. 2004, Kaligarič & Škornik 2006, 2007, Pandža et al. 2007, Shehu et al. 2010, Šajna et al. 2013), but there remain sites that have not yet been investigated. Among these is a coastal salt-marsh situated on the central east coast of the Adriatic in south Croatia. There is, in fact, no previous detailed study that describes the phytosociology of Cressa cretica L. (Convolvulaceae) - a rare plant of the salt-marshes in the Adriatic Basin. These matters are addressed by the present study, in which the halophytic vegetation with C. cretica is related to key soil factors.
Cressa cretica is a perennial plant (Pignatti 1982) with a lifecycle that continues in the summer period when the salt marsh area drains. Bouchard (1977) considers it an annual or perennial plant, while most authors from the Mediterranean area (cf. Ozenda 1983, Lorenzoni & Paradis 1994, Biondi et al. 2001, etc.), including Croatian authors (Milovic & Markovic 2003), have emphasized its therophytic character.
It occurs in the Mediterranean region and east through western and central Asia as far as India and south to northern and central Africa, also being found in South America, Australia and parts of South-east Asia, and it can be considered as a thermo-cosmopolitan halophilous species (Lansdown 2013). There is no information on whether some of these populations may be non-native. In addition, C. cretica is used in various folklore medicines (Priyashree et al. 2010, Rani et al. 2011). This species is included in the lUCN Red list of threatened species and being classed as Least Concern does not face any major threats (Lansdown 2013).
It has been found in the coastal areas of most Mediterranean countries (Greuter et al. 1986), and in some is included in national Red lists of plants (e.g. Italy, France, Bulgaria, etc.). According to the data in the literature, on the east Adriatic coast it is found at only one locality in Croatia (Milovic & Markovic 2003) and in Albania (Baldacci 1896, Ball 2011). According to the Flora Croatica Database (Nikolic 2014), this species is also found on two mid-Adriatic islands (Brač and Šolta) and the peninsula of Pelješac, mostly on gravel (Šolta, Pelješac) or gravel-muddy (Brač) substrates.
The aim of this paper is to contribute to the knowledge of the ecology and phytosociology of
C. cretica on the eastern Adriatic coast and in the Adriatic Basin generally.
2. STUDY AREA
The study area of Blato (Gauss-Krüger coordinates X = 5571512, Y = 4840171, UTM WJ 74) is located along the Republic of Croatia's central Adriatic coast (Figure 1). Phytogeographically this area belongs to the Mediterranean vegetation zone of thermophilic evergreen vegetation of the Fraxino orni-Quercion ilicis alliance (Trinajstic 1995, sensu Biondi et al. 2014).
Average annual air temperature is 15.4 °C and precipitation averages 773.8 mm yr-1 (data from the nearby town of Šibenik station for 1976-2006, Croatian Meteorological and Hydrological Service). The highest daily average temperature is 25.1 °C in July, and the lowest falls below 6.9 °C in January. The absolute minimum temperature (-8.6 °C) was recorded in January 1985, and the absolute maximum (39.2 °C) in August 1981. The greatest rainfall is in November (average 99.6 mm) and December (average 89.2 mm). In the period from June to August the rainfall is 121.9 mm. Northern winds prevail throughout the year. This area has 2,698 hours of sunshine per year. On average, the relative air humidity is 57%. In winter, the frequent northern wind called the 'bura' significantly decreases the relative air humidity.
The study area of Blato ('mud') is about 6 km from the town of Šibenik near the village of Zablace and the Solaris Resort. The village of Zablace has 500 year-round inhabitants, but this number increases several-fold in summer. Blato is a small salt-marsh about 250 m distant from the seacoast. At present it covers a surface area of ca. 5-6 ha. The vegetation is threatened by human activitivities and currently the situation is in a transitional stage of abandonment and the creation of new habitats.
The Blato coastal salt-marsh is colonized by various halophilous plant communities, whose species tolerate the periodical inundation by sea-water of their growing-sites, as well as the complete desiccation that give rise to halomorphic soils, characterized by a high saline concentration in the upper stratum. In practice, Blato is a shallow depression of silty and clay soils. For most of the year the soils have a high moisture content or are inundated to 5-10 cm with salt or brackish
Figure 1: Geographical position (▲) of the study area (Abbreviations: BIH: Bosnia and Herzegovina; MNE: Montenegro; AL: Albania).
Slika 1: Geografski položaj (▲) preučevanega območja (Okrajšave: BIH: Bosna in Hercegovina; MNE: Črna gora; AL: Albanija).
water. Water-depths in some deeper ditches and hollows are ca. 40-50 cm. The excess water is led away by a drainage channel passing through the Blato area and connecting the marine lake Velika Solina to the sea in Podsolaris Bay (Caric et al. 2011). During the summer, the salt-marsh area gradually drains due to low precipitation and high evaporation. In some years the deeper parts of the soil retain some of the moisture even in the driest period (July-August) due to the presence of groundwater.
3. MATERIAL AND METHODS
Fieldwork was carried out in August 2014. For data collection the Braun-Blanquet approach (Braun-Blanquet 1964) was used. Only stands with at least the minimum area recommended for these types of vegetation were investigated (Chytry & Otypkova 2003). In each association a reasonable degree of homogeneity was ensured. The syntaxonomic scheme in the text follows Ri-vas-Mart^nez et al. (2001). The nomenclature of higher syntaxa (alliances, classes) mentioned in the text and Table 1 was derived from Biondi et
al. (2014). The nomenclature of plant taxa follows the Flora Croatica Database (Nikolic 2014). Herbarium specimens are deposited in the herbarium collection of the Laboratory for terrestrial flora and fauna of the University of Dubrovnik. The biological forms were directly verified in the field and expressed according to the acronyms reported by Pignatti (1982) and based on the classification by Raunkiaer (1934). The abbreviations of life forms (Ch - Chamaephytes, H - Hemicryp-tophytes, G - Geophytes, T - Therophytes; Hy -Hydrophytes; scap - scapose, rhiz - rhizomatose, caesp - caespitose, succ - succulent, frut - fru-ticose, ros - rosulate, suffr - suffruticose, rad -rooting, nat - natant) are given in Table 1, before the each species name.
In order to verify the traditional syntaxonom-ic system, the releves were classified by numerical methods. The matrix consists of 22 species x 21 samples (releves). Braun-Blanquet values were transformed according to van der Maarel (1979). An agglomerative, hierarchical clustering algorithm based on Euclidean distances and Ward's method for determination of group linkages was used (McCune & Mefford 2006). Differences between groups obtained in classification were tested by analysis of similarities (ANOSIM). For these purposes the PC-ORD ver. 5 and PRIM-ERv6 software packages (McCune & Mefford 2006, Clarke & Gorley 2006) were used.
Three soil samples were randomly taken in the association Cressetum creticae over the salt-marsh, and one sample each in other associations (except in Enteromorpho intestinalidis-Ruppietum mariti-mae). Samples were collected at depth profiles of 0-20 cm. For the determination of soil properties the surface soil samples (average weight 2 kg) were air-dried and well mixed. A sub-sample of about 1 kg soil was sieved through a 2 mm mesh. For the soil salinity assessment, a soil saturation extract (ECe) was analyzed (US Salinity Laboratory 1954, Rhoades 1996). Soil samples were analyzed in the laboratory and subjected to the following analyses: i) grain size distribution (dry sieving and after dispersion with sodium pyro-phosphate; Dane & Topp 2002), ii) the electrical conductivity (ECe) and pH were measured in a soil saturation extract using a MettlerToledo MPC 227 conductivity/pH meter, iii) calcium carbonate (CaCO3) by the volumetric calcimeter method after HCl attack, iv) element concentrations in a soil saturation extract were determined using a Skalar San+Analyzer spectrofotometer
(Cl-) and an atomic emission spectrometer AAS PerkinElmer 3110 (Na+). Quality control procedures consisted of reagent blanks, duplicate samples and several referenced soil and sediment samples of a similar matrix from the interlabora-tory calibration programme (Houba et al. 1996). Maximum allowable relative standard deviation between replicates was set to 10%.
4. RESULTS
Cressa cretica L. appears within the four plant associations: Juncetum maritimo-acuti (Juncetea maritimi), Puccinellio festuciformis-Sarcocornietum fruticosae (Sarcocornietea fruticosae), Scirpetum maritimi (Phragmito australis-Magnocaricetea ela-tae) and Cressetum creticae (Thero-Suaedetea splend-entis, Table 1, Figure 2).
Figure 2: Dendrogram of the releves. Enteromorpho intesti-nalidis-Ruppietum maritimae (*), Cressetum creticae (A), Scirpetum maritimi (▲), Puccinellio festuciformis-Sarcocornietum fruticosae (□), Juncetum maritimo-acuti (■). Slika 2: Dendrogram popisov. Enteromorpho intestinalidis-Ruppietum maritimae (*), Cressetum creticae (A), Scirpetum maritimi (▲), Puccinellio festuciformis-Sarcocornietum fruticosae (□), Juncetum maritimo-acuti (■).
Among them, the Cressetum creticae (Figures 3 & 4) association was found for the first time in Croatia as well as on the eastern Adriatic coast.
The syntaxonomic synopsis of the Cressetum creticae is:
THERO-SUAEDETEA SPLENDENTIS Rivas-Mar-t^nez 1972
Thero-Suaedetalia splendentis Braun-Blanquet
& O. Bolos 1958
Thero-Suaedion splendentis Braun-Blanquet in Braun-Blanquet, Roussine & Negre 1952 Cressetum creticae Brullo & Furnari 1976
This halo-nitrophilous community shows a monospecific or paucispecific character and it is exclusively composed of therophytes. C. cretica is the characteristic and dominant species of the association. In fact the companions Salsola soda L. and Suaeda maritima (L.) Dumort. appear in some releves. Generally, the association shows highly variable vegetation cover (20-90%). This low vegetation (<30 cm) occupies the driest depressions (aproximately 30 cm lower than surrounding vegetation types) in the salt-marsh. The association develops in summer (most commonly in August) on silty clay substrates with organic matter derived from the decay of saltmarsh bulrush (Scirpus maritimus) and sub-halophyte communities of rushes (Juncetum maritimo-acuti) and widgeon grass (Enteromorpho intestinalidis-Ruppi-etum maritimae), in depressions subject to flooding in winter. According to World Reference Base for Soil Resources (lUSS Working Group WRB, 2006), the soil belongs to Solonchaks (Alcalic Clayic Evapocrustic Humic Hypersalic).
In total, the association covered a surface area of ca. 0.05 ha in 2014. According to observations of the second author (M. Milovic) over the last decade, due to climatological conditions in particular years more or less of this surface area may be covered by the association.
Cressa cretica appears in three other associations only sporadically, but it is presented over almost the whole salt-marsh surface area (Table 1). It is missing in the deepest parts of the salt-marsh covered by the Enteromorpho intestinalidis-Ruppi-etum maritimae association.
In terms of grain size, the soil samples were classified as silty-clay. Clay (<2 pm) and fine silt (2-20 pm) contents were much higher than coarse silt (20-63 pm) or sand (>63 pm). There were no differences of the soil grain-size distribution among the associations (Table 2). The main soil characteristics of the four associations of the marsh are summarized in Table 3. Among the associations, Cressetum creticae showed the highest electrical conductivity, Cl- and Na+ concentrations and Juncetum maritimo-acuti the lowest.
Figure 3: Spatial distribution of the associations in the investigated area: Cressetum creticae (1), Juncetum maritimo-acuti (2), Scirpetum maritimi (3), Puccinellio festuciformis-Sarcocornietum fruticosae (4) (photo: N. Jasprica, August 8, 2014). Slika 3: Prostorska razširjenost asociacij na preučevanem območju: Cressetum creticae (1), Juncetum maritimo-acuti (2), Scirpetum maritimi (3), Puccinellio festuciformis-Sarcocornietum fruticosae (4) (foto: N. Jasprica, 8. 8. 2014).
Figure 4: Cressetum creticae in the study area (photo: M. Milovič, August 31, 2008).
Slika 4: Cressetum creticae v proučevanem območju (foto: M. Milovič, 31. 8. 2008).
Both of them are established on the soils with the highest content of CaCO3 and humus.
5. DISCUSSION
This investigation revealed the presence of the halo-nitrophylic association Cressetum creticae in the eastern Adriatic coast.
This association has already been noted for Tunisia (Barbagallo et al. 1990), Corsica (Paradis & Tomasi 1991, Gehu & Biondi 1994, Lorenzoni & Paradis 1994, Paradis & Lorenzoni 1999), Sardinia (Biondi et al. 2001), Sicily (Brullo & Fur-nari 1976), Spain (Galan de Mera et al. 1997), and the south-western Adriatic coast (Tomaselli et al. 2010, 2011). Although C. cretica has also been reported from Albania, it does not build separate
plant associations (cf. Dring et al. 2002, Shehu et al. 2010, Imeri et al. 2010, etc.).
In our case, although relatively poor in species, the vegetation composition of the coastal salt-marsh is a mosaic of five plant associations that grow on soils with the same grain-size distribution. Among them, Cressetum creticae occupies the most haline and the driest parts of the salt-marsh. These agree well with the ecological conditions in the Tunisian and Italian associations (Barbagallo et al. 1990, Biondi et al. 2001). Some of the authors who have studied plant communities with C. cretica (Brullo & Furnari 1970, Ciru-jano 1981, Ladero Alvarez et al. 1984) note the coincidence in the frequent appearance of salty efflorescences in these soils. In our case, such salty efflorescences have been found in these soils in the very dry summer of 2008 (cf. Mileta & Likso 2009). In this study, due to the limited number of soil analysis samples collected during the exceptionally rainy summer of 2014, the results may be treated as an approximation rather than definitive.
In Croatia and in most Mediterranean sites, Cressetum creticae has a generally monospecific or paucispecific character. The Croatian association differed from the south-western Adriatic association (Brindisi) which included some more species (8), mostly from the Saginetea maritimae class (Tomaselli et al. 2011).
In our study, Cressetum creticae has connections with the topographic perennial halophyte communities of the Sarcocornietea fruticosae and Juncetea maritimi classes, even of the Phragmito australis-Magnocaricetea elatae class. This agrees with the findings of Barbagallo et al. (1990), Lor-enzoni & Paradis (1994) and Biondi et al. (2001). In fact, C. cretica appears within four associations. Others have commented on the presence of C. cretica within some communities of Thero-Suaedetea splendentis, Sarcocornietea fruticosae, Saginetea maritimae or Isoeto duriei-Juncetea bufonii on Sicily (Guglielmo et al. 2012), Sardinia (Biondi et al. 2001), Corsica (Lorenzoni & Paradis 1994) and in Spain (Ladero Alvarez et al. 1984).
Despite lack of data on the phytosociological and ecological status of C. cretica from two Croatian islands, the most common species found with it on the gravel or gravel-muddy coasts were: Atri-plexprostrata Boucher ex DC. in Lam. et DC., Ely-mus elongatus (Host) Runemark, Limonium cancel-latum (Bernh. ex Bertol.) Kuntze, Arthrocnemum fruticosum (L.) Moq., Inula crithmoides L. and Re-
ichardia picroides (L.) Rot. (Nikolic 2014). C. cre-tica is a quite rare and sporadic species on these localities (M. Ruščic, pers. comm.). In addition, on the peninsula of Pelješac only a few individuals have been found at a fine-pebbly beach, where organic material, carried by the sea, accumulates and decomposes (T. Nikolic, pers. comm.).
Cressetum creticae is closely related to the western Adriatic associations Suaedo-Salicornietum patulae and Suaedo maritimae-Bassietum hirsutae (Poldini et al. 1999, Tomaselli et al. 2011). Nevertheless the Suaedo maritimae-Bassietum hirsutae association is incompletely developed within the north Adriatic, due to the absence of two characteristic species: Cressa cretica is completly missing and Bassia hirsuta has become rare north of Ravenna (Poldini et al. 1999, Kaligarič & Škornik 2006).
Regarding syntaxonomy, we subordinated Cressetum creticae to the pioneer communities of annual glassworts, seablite and other halo-nitro-philes on tidal mud-flats of the Thero-Suaedetea splendentis class (Brullo & Furnari 1976, Lorenzo-ni & Paradis 1994, Rivas-Mart^nez et al. 2001, Di Pietro et al. 2009, Tomaselli et al. 2010, 2011). By contrast this association from the west Mediterranean has been mostly subordinated to the Saginetea maritimae class (cf. Biondi et al. 2001, Far-ris et al. 2007) or to its synonym the Frankenietea pulverulentae class (Ladero Alvarez et al. 1984, Galan de Mera et al. 1997, for details see Brullo & Giusso del Galdo 2003). In fact, some Spanish authors (cf. Rivas-Mart^nez & Costa 1976, Rivas-Mart^nez et al. 1980) included some associations of the Thero-Suaedion splendentis allliance to the Frankenietea pulverulentae class. However, the typical associations of the Saginetea maritimae class are therophytic, halo-subnitrophilous communities with their maximum expression in the early spring, being characterized by microphytes with a very early flowering (Brullo 1988, Brullo & Giusso del Galdo 2003). By contrast, the halo-nitrophilous associations of the Thero-Suaedion splendentis alliance are in particular characterized by therophytic aspects of habitus in general with a succulent summer-autumn cycle (eg. Cressa cre-tica, Salsola soda, Suaeda maritima, etc.). We think that Cressetum creticae must be included in Thero-Suaedetea splendentis.
This Croatian coastal salt-marsh, including the habitat of C. cretica, is exposed to many disturbances. Regarding human presence in the area, alongside urban and industrial land use, hy-drologic alteration and/or eutrophication are the
main factors which influence the physiognomy and floristic composition of the salt-marsh communities (cf. Bromberg Gedan et al. 2009). This vegetation is also of interest and important from the conservational perspective as being threatened by all factors mentioned above. In addition, this salt-marsh with different types of halophyte vegetation is important due the presence of habitats of European or global significance for protection or for botanical interest (Council of the European Communities 1992, European Commission 2007). In contrast to some west Mediterranean sites (Spain, Corsica), where communities with C. cretica are active pastures, in our case the habitat is an important part of the ecosystem in terms of the aesthetics of landscape.
In summary, this study adds to the base of information on the structure and function of small Mediterranean coastal salt-marsh. Of particular note, the presence of the Cressetum creti-cae distinguishes this system from those of other salt-marshes in the region. Stands with C. cretica are extremely rare on the eastern Adriatic coast and, owing to heightened coastal development, perhaps in the process of becoming extinct. They nevertheless are an important part of the region's natural heritage in need of conservation measures to ensure their survival. It was in this context that the present ecological investigation was conducted in August 2014.
Enteromorpho intestinalidis-Ruppietum maritimae
Westhoff ex Tüxen & Böckelmann 1957 Frankenietea pulverulentae Rivas-Mart^nez ex
Castroviejo & Porta 1976 Fraxino orni-Quercion ilicis Biondi, Casavecchia & Gigante ex Biondi, Casavecchia & Gigante in Biondi, Allegrezza, Casavecchia, Galdenzi, Gigante & Pesaresi 2013 Isoeto duriei-Juncetea bufonii Braun-Blanquet &
Tüxen ex Westhoff, Dijk & Passchier 1946 Juncetea maritimi Braun-Blanquet in Braun-Blan-
quet, Roussine & Negre 1952 Juncetum maritimo-acuti Horvatic 1934 Phragmito australis-Magnocaricetea elatae Klika in
Klika & Novak 1941 Puccinellio festuciformis-Sarcocornietum fruticosae
(Braun-Blanquet 1928) Gehu 1976 Ruppietea maritimae J. Tüxen 1960 Saginetea maritimae Westhoff, Van Leeuwen &
Adriani 1962 Sarcocornieteafruticosae Braun-Blanquet & Tüxen ex A. Bolos & O. Bolos in A. Bolos 1950 nom. mut. propos. Rivas-Mart^nez, T.E. D^az, Fern-andez-Gonzales, Izco, Loidi, Lousä & Penas 2002
Scirpetum maritimi (Braun-Blanquet 1931) Tüxen 1937
Suaedo maritimae-Bassietum hirsutae Braun-Blan-quet 1928
Suaedo maritimae-Salicornietum patulae Brullo & Funari ex Gehu & Gehu Franck 1984
ACKNOWLEDGEMENTS
We thank Drs. Marija Pandža, Rade Garic and Nikša Glavic for technical support and two anonymous reviewers for their constructive comments on an earlier version of this manuscript. Thanks are also extended to Steve Latham (UK) for improving the English.
APPENDIX
Syntaxonomic units mentioned in the text and Table 1, but not in the scheme (in alphabetical order).
Ammophiletea Braun-Blanquet & Tüxen ex Westhoff, Dijk & Passchier 1946 Artemisietea vulgaris Lohmeyer, Preising & Tüxen
ex von Rochow 1951 Cakiletea maritimae Tüxen & Preising in Tüxen 1950
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Received 11. 10. 2014 Revision received 1. 12. 2014 Accepted 3. 12. 2014
Table 1: Phytosociology of Cressa cretica in the study area.
Tabela 1: Fitocenologija vrste Cressa cretica na proučevanem območju.
Number of releves
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Vascular plant cover (%) Plot size (m2) Number of species
80 50 20 50 60 80 30 30 30 90 90 90 80 80 90 100 80 50 40 50 100 10 6 10 12 8 10 25 10 10 16 25 25 25 20 6 10 30 25 25 25 4
2 2 1 1 1 1 1 1 2 3 8 11 12 12 4 5 6 8 8 11 2
Thero-Suaede^ea splenden^i^
T scap Cressa cretica L. T scap Suaeda maritima (L.) Dumort. Juncetea maritimi
G rhiz Juncus maritimus Lam. H caesp Juncus acutus L.
Phragmito australis-Magnocaricetea elatae
G rhiz Scirpus maritimus L. G rhiz Phragmites australis (Cav.) Trin. ex Steud. Sarcocornietea fruticosae
Ch succ Arthrocnemum fruticosum (L.) Moq. Ch frut Halimione portulacoides (L.) Aellen H caesp Puccinellia festuciformis (Host) Parl. H ros Limonium narbonense Mill. H caesp Elymus elongatus (Host) Runemark Ch suffr Inula crithmoides L.
Ch succ Arthrocnemum macrostachyum (Moric.) C. Koch Ch suffr Artemisia caerulescens L.
Cakiletea maritimae T scap Salsola soda L.
Saginetea maritimae T scap Polypogon maritimus Willd. T scap Centaurium spicatum (L.) Fritsch T scap Centaurium pulchellum (Sw.) Druce
Artemisietea vulgaris T scap Aster squamatus (Spreng.) Hieron. Ruppietea maritimae
Hy rad/nat Ruppia maritima L.
Enteromorpha intestinalis (L.) Nees
Ammophiletea G rhiz Elymus pycnanthus (Godr.) Melderis
4424453335 1
+ + + +
4 3 3 2 .+22
4 5 4
2	+	+	1.		.3	2	3
	1	+	+ 1	1	+ 1	4	2
+		+	+ .	+	. +	+	+
+	+	+	+ .	+	+ +	+	+
+	+	+	+ 1				+
. + + + + + + + +
5
+
rel. 1-10.	Cressetum creticae
rel. 11-14.	Juncetum maritimo-acuti
rel. 15-17.	Scirpetum maritimi
rel. 18-20.	Puccinellio festuciformis-Sarcocornietum fruticosae
rel. 21.	Enteromorpho intestinalidis-Ruppietum maritimae
+
+ +
+
+ +
+
++
+
+
+ +
+ + +
+
+
+
+ +
+
+ +
+
+
Table 2: Grain-size of soil samples in the associations. Tabela 2: Velikost delcev v tleh v različnih asociacijah.
Association			Grain size (%)		
	<2 ^m	2-20 ^m	20-63 ^m	63-200 ^m	200-2000 ^m
Cressetum creticae (sample 1)	57	26	13	2	2
Cressetum creticae (sample 2)	47	31	17	3	2
Cressetum creticae (sample 3)	50	28	16	3	3
Juncetum maritimo-acuti	46	30	18	3	3
Puccinellio festuciformis-Sarcocorni-etum fruticosae	52	29	15	2	2
Scripetum maritimi	51	28	17	2	2
Table 3: The soil characteristics (± SD) of the associations of the Blato salt-marsh (SD = standard deviation). Tabela 3: Značilnosti tal (± SD) v asociacijah v slanišču Blato (SD = standardni odklon).
Association		soil saturation extract					
	PH	ECe	Cl-	Na+	%	CaCOj	Humus
		dS m-1	g L-1	g L-1	saturation	%	%
Cressetum creticae (n=3)	8.03 ± 0.13	44.5 ± 10.69	18.62 ± 5.76	8.78 ± 2.40	81.81 ± 8.03	19.84 ± 9.22	2.86 ± 1.46
Juncetum maritimo-acuti	8.30	14.86	4.82	2.79	77.91	20.71	2.18
Puccinellio festuciformis-	8.20	32.30	11.85	6.74	75.41	7.77	1.51
Sarcocornietum fruticosae							
Scripetum maritimi	8.26	25.10	8.63	5.40	82.56	8.20	1.72