Iskanje po katalogu digitalne knjižnice

Opis: Changes in soil chemistry after invasion by bracken (Pteridium aquilinum) have been studied in heathlands, but comparable studies in meadows are lacking. We investigated if bracken invasion into P-deficient meadows alters the soil nutrient-resource pool, as well as the mechanisms behind it linked to soil processes and bracken nutrition. Furthermore, we investigated how community composition responds to differences in soil chemistry before and after the invasion. Soil and plant material sampling, along with vegetation survey, were performed during bracken peak biomass. Data analyses included analysis of variance and canonical correspondence analysis (CCA). Bracken invasion increased soil P availability, soil organic C concentration, as well as C:N, C:S and N:S ratios, while decreasing Fe and Co concentrations. Bracken pinnae were rich in P, and its rhizomes were rich in K, whereas N:P of pinnae and rhizomes was low. CCA showed contrasting abundance patterns of frequent meadow species related to P and K availability. Holcus lanatus exhibited competitive advantage under extremely low P availability. Increase in P availability under bracken may have occurred through promoting the leaching of Fe and Al. By increasing P availability for its growth and increasing N limitation for other species, bracken can gain a competitive advantage from the soil resource-niche perspective. Its ability to increase soil P availability, along with the physiological mechanisms behind its high P acquisition efficiency, seem to differentiate bracken from other species of competitive ecological strategy, which are mainly confined to nutrient-rich environments. This enabled bracken to invade P-deficient meadows.
Ključne besede: vegetation succession, invasive species, biogeochemical processes, soil ecology, plant invasion
Objavljeno v DKUM: 17.06.2024; Ogledov: 148; Prenosov: 8
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Opis: According to recent molecular analyses of Salicornia, we revised the annual glassworts from the Croatian coast, classified until now only as Salicornia europaea. Two species, a diploid Salicornia patula and a tetraploid S. emerici were recognized. They can be easily distinguished by floral characters, but not only by their habitus, which varies extremely according to environmental factors. Both species differ also in seed morphology. Salicornia patula has dimorphic seeds, with larger central seeds reaching high germination rates. Germination patterns helped to explain the habitat preferences. The species rarely co-occur, however. The rare S. patula occupies drier habitats, on coastal mudflats or sands that are irregularly inundated. It occurs within the assoc. Suaedo maritimae-Salicornietum patulae. Salicornia emerici occupies the lowest coastal mudflats, regularly inundated, where nutrient-rich conditions prevail, and forms an almost monotypical assoc. Salicornietum emerici. Due to the synonymy of S. veneta with S. emerici, we exclude the occurrence of S. veneta in Croatia as an independent taxon.
Ključne besede: botany, vegetation, Croatia
Objavljeno v DKUM: 28.03.2017; Ogledov: 1108; Prenosov: 454
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Opis: The aim of the study was to compare how the relevés of species-rich dry grasslands (classis Festuco-Brometea) in Central and Eastern Slovenia differ among each other on the basis of floristic composition and of 11 Plant Functional Traits (PFTs). On the basis of floristic structure and cover values, the relevés were classified in three well separated clusters. In the PCA ordination, the first axes suggested a gradient of soil pH, while the second, floristically based gradient, was interpreted as soil humidity. On the basis of selected traits, 3 PFTs were clustered, but not clearly interpreted. Despite differences in environmental parameters across Slovenia (climate, geographical position, altitude, soil conditions) and variety of land use disturbances - drivers of floristic variety, no discernible difference in vegetation structure in terms of selected plant traits were perceived by PCA ordination. It could be concluded that secondary dry grasslands share rather uniform functional types with not clearly detectable structural differences among them.
Ključne besede: botanika, vegetacija, biogeografija, travišča, suha travišča, rastlinski funkcionalni znaki, rastlinski funkcionalni tipi, Slovenija, funkcionalni pristopi, botany, biogeography, vegetation, grasslands, dry grasslands, plant functional traits, plant functional types, Slovenia, functional approaches
Objavljeno v DKUM: 10.07.2015; Ogledov: 1530; Prenosov: 42
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Opis: In this paper, floristic and functional approaches to the classification of different types of sub-Mediterranean illyrian grasslands of the association Danthonio-Scorzoneretum villose lalliance Scorzonerion villosae, order Scorzoneretalia villosae, class Festuco-Brometea) are compared. The data set includes table with 30 relevés from SW Slovenia, sampled in two contrasting geological bedrocks - flysch and limestone - and matrix with 18 treits determined for 119 plant species. We also tested an impact of different geological bedrock on the relative proportions of C-S-R plant strategies in the relevés. With DCA ordinetion, relevés from limestone and flysch were clearly divided in two groups. First DCA axis suggested a gradient of soil humidity and pH. On the basis of selected traits, 5 Plant Functional Types were clustered and interpreted with Twinspan analysis. PCA ordination of relevés on the basis of plant functional traits revealed that samples from limestone could be separated from those taken on flysch substrate also with functional approach. Reievés from limestone tend to have bigger shares of species, which propagate by seed and vegetatively, and competitors and herbs. Nevertheless, it could be concluded that there are no major functional differences between meadows from both geological substrates. The positions of all relevés in standard C-S-R temary diagram showed that that the relative proportions of C-S-R functional types were not influenced by different geological bedrock.
Ključne besede: botanika, vegetacija, travišča, suhi travniki, rastlinski funkcionalni tipi, severni Jadran, C-S-R strategije rastlin, botany, biogeography, vegetation, grasslands, dry grasslands, classifcation, North Adriatic, C-S-R plant strategy
Objavljeno v DKUM: 10.07.2015; Ogledov: 1676; Prenosov: 40
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Ključne besede: botanika, vegetacija, halofiti, kalitev, botany, vegetation, halophytes, germination, Salicornia
Objavljeno v DKUM: 10.07.2015; Ogledov: 1501; Prenosov: 49
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