Stepi podobna traviška vegetacija na hribih okoli jezer Vegoritida in Petron v severno centralni Grčiji

The present paper describes the floristic composition and synecology of steppe-like dry grasslands occurring in a Natura 2000 site in North-Central Greece around the two karstic lakes of Vegoritida and Petron. In total, 245 relevés of vascular plant species composition and abundance were sampled and subjected to cluster analysis and ordination analysis. Passive explanatory variables, including environmental parameters as well as indicator values, were used to support the ecological interpretation. Four plant communities were distinguished in the area, namely Artemisia campestris-Dasypyrum villosum, Chrysopogon gryllus-Bothriochloa ischaemum, Satureja montana-Artemisia alba and Stipa capillata-Koeleria macrantha. All communities were classified within the Festuco-Brometea class and the Astragalo-Potentilletalia order. Soil properties (soil reaction, moisture and nutrient content) and meso-climate factors (temperature variation along topographic gradients) were identified as the main factors determining the floristic differentiation among the four communities. The dry grasslands harbor a number of species associated with steppic habitats. We discuss the relict character of the steppe-like vegetation.V članku opisujemo floristično sestavo in sinekologijo stepi podobnih suhih travišč, ki se pojavljajo v Natura 2000 območju v severni centralni Grčiji okoli dveh kraških jezer Vegoritida in Petron. Vzorčili smo 245 vegetacijskih popisov in jih analizirali s klastrsko in ordinacijsko analizo. Rastišče smo interpretirali s pasivnimi pojasnjevalnimi spremenljivkami, kamor smo vključili okoljske spremenljivke in indikatorske vrednosti. Na raziskovanem območju smo ločili štiri rastlinske združbe: Artemisia campestris-Dasypyrum villosum, Chrysopogon gryllus-Bothriochloa ischaemum, Satureja montana-Artemisia alba in Stipa capillata-Koeleria macrantha. Vse združbe smo uvrstili v razred Festuco-Brometea in red Astragalo-Potentilletalia. Lastnosti tal (reakcija tal) in mezo klimatski dejavniki (spreminjanje temperature vzdolž topografskih gradientov) so glavni dejavniki, ki vplivajo na floristične razlike med štirimi rastlinskimi združbami. V suhih traviščih najdemo številne vrste stepskih habitatov. V članku razpravljamo o reliktnem značaju stepi podobne vegetacije

Abundance, diversity and distribution of macrophyte communities in neighboring lakes of different trophic states and morphology in north-central Greece

The role of aquatic vegetation in wetland ecosystems is closely related with their abundance, diversity and distribution, which in turn represents synergy of various environmental factors. The floristic composition of the aquatic vegetation in two neighboring lakes (Vegoritida and Petron) in north-central Greece was investigated by means of 160 relevés, which were recorded using the Braun-Blanquet method. The analysis of relevés based on TWINSPAN clustering showed the existence of 10 plant communities from the Lemnetea, Potametea, Phragmito-Magnocaricetea and Juncetea maritimi classes. The most important environmental factors for the vegetation differentiation in the study area, according to the ordination diagram, are light intensity and water depth of the habitats. The plant species diversity was quantified with species richness, Shannon Diversity and evenness indices at a scale of each relevé, with a sampling size of 20 m2. There was a clear differentiation between the relevés at the more eutrophic Petron Lake and those at Vegoritida Lake. The mean plot diversity was also calculated for each plant community, to enable comparison of the diversity indices among the communities at the plot level

GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

The ecosystem of lakes Vegoritida and Petron: flora, vegetation and plant geography

The aim of the present study is to investigate the flora and the vegetation in the Natura 2000 network site “Limnes Vegoritida – Petron” (GR 1340004). The study area is located at north-central floristic region of Greece, in W. Macedonia, and characterized by the presence of dry calcareous grasslands, as well as it hosts forests of Quercus trojana, a Balkan species with restricted and phytogeographically interesting distribution. To investigate the flora of the study area, ca. 2500 plant speciments were collected from 15 major, geographically defined, collecting localities. In total 615 terrestrial and 49 aquatic taxa were recorded. The present study revealed the existence of two new taxa for Greece, five taxa new for the phytogeographical region of north-central Greece and four aquatic taxa are considered rare in Greece. 648 relevés were conducted according to the Braun-Blanquet method. Vegetation data were analyzed applying multivariate, numerical methods of classification and ordination. The classification of the terrestrial vegetation resulted in the distinction of four ecological groups, which comprise 13 communities, 15 sub-communities and one facies. The first group includes ruderal communities of synanthropic vegetation. It appears at the transitional zone between natural vegetation and cultivations, around the lakes and at the edges of roads close to human settlements. The floristic differentiation of this group is probably caused by the increased soil humidity and nutrients availability. The second group corresponds to rock-cliff and scree vegetation, and it grows on screes that have been formed by the erosion of the substrate from the surrounding hills or have been built by human for the construction of a railway, as well as, on smaller or larger spots, where the substrate is superficial. The ecological differentiation of this group may be attributed to the dry and warm microclimate conditions due to reduced water-holding capacity of the substrate. The third group includes the thermophilous deciduous forests with Quercus trojana. These communities represent tree and shrub vegetation with relatively low cover and rich in herbaceous species. The floristic differentiation of this group may be attributed to the optimal moisture and temperature conditions, due to shade of the tree and shrub layer. The fourth group corresponds to calcareous steppe-like vegetation of low altitudes. It includes vegetation units dominated by grasses, on eroded soils of small depth. Differentiation of soil properties (e.g. presence of gravels or superficial substrate) causes a mosaic of soil moisture and temperature conditions, which form a correspondence mosaic of drought-resistant herbaceous species and scattered shrub species. Plant communities of this ecological group are composed by taxa growing under direct sunlight and at more continental climates than those recorded in the rest plant communities of the study area. The phytosociological relevés of the aquatic vegetation were classified into seven associations, three communities and five sub-associations. The floristic differentiation of the aquatic vegetation units may be attributed to its distance from the shoreline and water depth, factors that determine the zonation of vegetation in aquatic ecosystems. The submerged associations of Magnopotamion and Parvopotamion occur at higher distance from the shore and at deeper waters, the communities which characterized by the presence of floating species grow near the shoreline, at sites periodically flooded, and emerged communities occur at sites outside the lakes.Σκοπός της παρούσας διατριβής είναι η μελέτη της χλωρίδας και της βλάστησης στην περιοχή «Λίμνες Βεγορίτιδα – Πετρών» (GR 1340004) του δικτύου ΦΥΣΗ 2000. Η περιοχή έρευνας βρίσκεται στη δυτική Μακεδονία, στη φυτογεωγραφική περιοχή της βορειο-κεντρικής Ελλάδας και χαρακτηρίζεται από την παρουσία εκτεταμένων ασβεστολιθικών γρασιδιών στους λόφους γύρω από τις λίμνες, αλλά και δρυοδάσους μακεδονικής δρυός (Quercus trojana), ενός είδους με περιορισμένη γεωγραφική εξάπλωση. Για τη μελέτη της χλωρίδας συλλέχθηκαν, περίπου 2500 φυτικά δείγματα, από 15 γεωγραφικά οριζόμενες περιοχές συλλογής. Συνολικά, καταγράφηκαν στην περιοχή 615 χερσαία και 49 υδρόβια φυτικά taxa. Δύο taxa αναφέρονται για πρώτη φορά στον Ελλαδικό χώρο, πέντε taxa αναφέρονται για πρώτη φορά στο φυτογεωγραφικό διαμέρισμα της βορειο-κεντρικής Ελλάδας και τέσσερα υδρόβια taxa αποτελούν είδη σπάνια για την Ελλάδα. Η μελέτη της βλάστηση έγινε με βάση τη μέθοδο του Braun – Blanquet και μέσω της δειγματοληψίας 648 επιφανειών. Η επεξεργασία των δεδομένων βλάστησης έγινε με τη χρήση πολυμεταβλητών μεθόδων αριθμητικής ταξινόμησης και ταξιθέτησης. Στη χερσαία βλάστηση, διακρίθηκαν 4 οικολογικές ομάδες που περιλαμβάνουν 13 φυτοκοινότητες, 15 υπο-φυτοκοινότητες και 1 όψη. Η πρώτη ομάδα περιλαμβάνει ημι-νιτρόφιλες και νιτρόφιλες κοινωνίες συνανθρωπικής βλάστησης. Αναπτύσσεται στη μεταβατική ζώνη μεταξύ της φυσικής βλάστησης και των καλλιεργειών, στις ακτές περιμετρικά των δύο λιμνών και στις παρυφές των δρόμων γύρω από τους οικισμούς της περιοχής έρευνας. Η χλωριδική διαφοροποίηση της ομάδας αυτής, πιθανώς, σχετίζεται με την αυξημένη περιεκτικότητα θρεπτικών στο έδαφος και την ένταση ανθρωπογενών διαταραχών. Η δεύτερη ομάδα αντιστοιχεί σε βλάστηση που αναπτύσσεται πάνω σε ασβεστολιθικές σάρρες που έχουν προέλθει από τη μηχανική διάβρωση των υπερκείμενων λόφων ή έχουν δημιουργηθεί από τον άνθρωπο κατά την κατασκευή της σιδηροδρομικής γραμμής, αλλά και σε σημειακούς ή ευρύτερης έκτασης σταθμούς, όπου το μητρικό πέτρωμα είναι επιφανειακό. Η οικολογική διαφοροποίηση της ομάδας αυτής, πιθανά οφείλεται στο ξηρό και θερμό μικροκλίμα των σταθμών, λόγω της μειωμένης ικανότητας υδατοσυγκράτησης του υποστρώματος. Η τρίτη ομάδα περιλαμβάνει τη βλάστηση των θερμόφιλων δρυοδασών της μακεδονικής δρυός. Πρόκειται για χαμηλή δενδρώδη και θαμνώδη βλάστηση, που χαρακτηρίζεται από πλούσια χλωρίδα, λόγω της χαλαρής δομής του ανωρόφου και του πετρώδους υποστρώματος. Η χλωριδική διαφοροποίηση των θερμόφιλων δρυοδασών, πιθανώς, οφείλεται στις ευνοϊκότερες συνθήκες υγρασίας και θερμοκρασίας, λόγω της σκιάς του φυλλώματος των κυρίαρχων δενδρωδών και θαμνωδών ειδών. Η τέταρτη ομάδα αντιστοιχεί στη στεππόμορφη ασβεστολιθική βλάστηση των χαμηλών υψομέτρων. Περιλαμβάνει μονάδες βλάστησης γρασιδιών πάνω σε διαβρωμένα και μικρού βάθους εδάφη. Η διαφοροποίηση των εδαφικών συνθηκών δημιουργεί ένα πολύπλοκο μωσαϊκό κοινοτήτων ξηροφυτικών ειδών με σποραδική παρουσία θαμνωδών taxa. Η βλάστηση γρασιδιών χαρακτηρίζεται από την αυξημένη παρουσία ειδών με ηπειρωτική εξάπλωση, ενώ χλωριδικά διαφοροποιείται από τις υπόλοιπες οικολογικές ομάδες, κυρίως λόγω της έντονης ηλιακής ακτινοβολίας. Από την επεξεργασία των δειγματοληπτικών επιφανειών της υδρόβιας βλάστησης προέκυψαν 7 φυτοκοινωνίες, 3 φυτοκοινότητες και 5 υπο-φυτοκοινωνίες, η χλωριδική διαφοροποίηση των οποίων αντικατοπτρίζει τη ζωνώδη ανάπτυξη των φυτοκοινωνιών ενός υδάτινου οικοσυστήματος. Οι υφυδατικές κοινωνίες των ενώσεων Magnopotamion και Parvopotamion αναπτύσσονται σε μεγαλύτερη απόσταση από την ακτή και χαρακτηρίζονται από μεγαλύτερα βάθη, οι κοινότητες που περιλαμβάνουν εφυδατικά είδη απαντώνται σε θέσεις που περιοδικά γεμίζουν με νερό και οι υπερυδατικές κοινότητες αναπτύσσονται εξωτερικότερα από την ακτογραμμή

Benchmarking plant diversity of Palaearctic grasslands and other open habitats

Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m(2) and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file "GrassPlot Diversity Benchmarks" and the web tool "GrassPlot Diversity Explorer" are now available online () and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology

Benchmarking plant diversity of Palaearctic grasslands and other open habitats

Aims Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location Palaearctic biogeographic realm. Methods We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology

Benchmarking plant diversity of Palaearctic grasslands and other open habitats

Abstract Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m² and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology