Explore the vast range of titles available.

The high-biodiversity phenomenon of the Balkan Peninsula is a result of the past and present topographic, climatic and geological conditions, as well as human impact. The Dinaric Alps, as a part of the Balkan Peninsula, harbour a high number of endemic species, some of them comprising a small number of populations, which are often endangered. We investigated spatial distribution, community composition, site ecology, genetic diversity and conservation of Degenia velebitica , a stenoendemic species of the north-western Dinaric Alps. Our results showed that D. velebitica is nowadays restricted to three localities with the area of occupancy of 48,560 m 2 , harbouring approximately 37,000 individuals. Degenia velebitica stands are differentiated into three well-characterized, floristically homogenous syntaxa, very distinct from the surrounding vegetation, suggesting their azonal occurrence and restriction to spatially highly fragmented microsites exposed to stormy winds. Spatial distances of populations, differences in D. velebitica community composition and site ecology are mirrored in genetic variation patterns of the populations, such as high-frequency down-weighted marker values in the north-western populations and high gene diversity in the south-eastern group of populations. The fact that we could not find a single D. velebitica individual at the locus classicus indicates the existence of the ever-growing fragmentation. The analyses of genetic structure using AFLP data recognized two main genetic groups of populations as evolutionary significant units that should be considered when planning protection measures. According to our IUCN Red List reassessment, D. velebitica should be treated as a critically endangered species that requires immediate conservation actions.

The relationships within the Alpine-Dinaric and cultivated populations of the genus Iris, Pallidae series, have been analysed. Seven morphological characteristics (stem length, length of the largest leaf, greatest width of the largest leaf, length of the smallest leaf, greatest width of the smallest leaf, the number of leaves and the number of flowers) and seven leaf anatomical (length and width of stomata, length and width of epidermal cells, number of stomata and epidermal cells per mm'- and length of styloids) have been used for this purpose. Relationships between populations were analysed by methods of multivariate statistics (Cluster, PCA and MST analyses). The results of Cluster and PCA analyses showed that, owing to leaf anatomical features, five main groups of the populations could be distinguished within the Pallidae series. Four of them belong to the species L. pallida, L. cengialti, L. illyrica and I. pseudopallida. The MST analyses showed that the fifth group contained mixed populations of I. illyrica and I. pseudopallida. The results point at the lack of taxonomic usefulness of the leaf anatomical features analysed and indicate that they caused successive geographical differentiation of the populations of the Pallidae series.

Intra- and interpopulational relationships and taxonomic status of six natural black pine populations (Pinus nigra Arnold) from Croatia were analyzed. Special attention in this research was paid to the establishment of taxonomic status and distribution of stenoendemic Dalmatian black pine (Pinus nigra Arnold subsp. dalmatica (Vis.) Franco). Three morphological and twenty-one anatomical traits of needles were used as well as analysis by the methods of multivariate statistics. Most of the researched individuals showed strong population affiliation, whereas a clinal transition of morphological and anatomical traits of needles was determined among the populations. The opinion of the existence of three subspecies of black pine on the territory of Republic of Croatia (Pinus nigra Arnold subsp. nigra, Pinus nigra Arnold subsp. dalmatica (Vis.) Franco and Pinus nigra Arnold subsp. illyrica (Vid.) Fukarek) was confirmed. For each of the three subspecies new ranges were represented. Four Croatian populations were included in the stenoendemic subspecies of the Dalmatian black pine (Brač, Hvar, Grobnik and Pelješac), and a new distribution, broken in two, was suggested. Since the Dalmatian black pine has been reduced to several populations only, and there are some signs of continuous diminishing of its range, this research points out the need of making an action plan to preserve all natural populations of this subspecies.

The relationships within the Alpine-Dinaric and cultivated populations of the genus Iris, Pallidae series, have been analysed by methods of multivariate statistics (Cluster, PCA and MST analyses). The bases for multivariate analyses were seven morphological characteristics (stem length, length of largest leaf, greatest width of the largest leaf, length of smallest leaf, greatest width of the smallest leaf, the number of leaves and the number of flowers) and relative chromosome length for 12 chromosome pairs. In spite of two similar looking isolated populations (Stara Baška and Konavle), the presence of four groups within the series was established, to which a species status can be ascribed: I. pallida Lam. separated as a horticultural species, /. cengialti Ambr. - endemic in Alpine region, /. illyrica Tomm. - endemic to the northern Adriatic Littoral and I. pseudopallida Trinajstić - endemic to the southern Adriatic Littoral. To differentiate the established groups, in PCA analysis the most significant features turned out to be: relative chromosome length of eleventh and tenth chromosome pairs, the length of the smallest leaf, relative chromosome length of the seventh chromosome pair and length of the stem.

Very frequently biological databases are used for analysing distribution of different taxa. These databases are usually the result of variable sampling effort and location uncertainty. The aim of this study was to test the influence of geographically biased sampling effort and spatial uncertainty of locations on models of species richness. For this purpose, we assessed the pattern of invasive alien plants in Croatia using the Flora Croatica Database. The procedure applied in testing of the sensitivity of models consisted of sample area sectioning into coherent ecological classes (hereinafter Gower classes). The quadrants were then ranked based on sampling effort per class. This resulted in creation of models using varying numbers of quadrants whose performance was tested with independent validation points. From this the best fitting model was determined, as well as a threshold of sampling effort. The data from quadrants with sampling effort below the threshold were considered too unreliable for modelling. Further, spatial uncertainty was simulated by adding a random term to each location and re-running the models using the simulated locations. Biased sampling effort and spatial uncertainty of locations had similar effects on model performance in terms of the magnitude of the affected area, as in both cases 7% of the quadrants showed statistically significant deviations in alien plant species richness. The model using only on the quandrants with the highest 35% quantile sampling effort best balanced the sampling effort per quadrant and overall geographical coverage. It predicted a mean number of 3.2 invasive alien plant species per quadrant for the Alpine region, 5.2 for the Continental, 6.1 for the Mediterranean and 5.3 for the Pannonian region of Croatia. Thus, the observational databases can be considered as a reliable source for species richness models and, most likely, for other types of species distribution models, given that their limitations are accounted for in the data selection process. In order to obtain precise estimates of species richness it is required to sample the whole range of ecological conditions of the study area.

The Campanula pyramidalis complex is a group of closely related taxa with a distribution across the Balkans, from the Gulf of Trieste in the north to the Peloponnese Peninsula in the south, with small disjunct parts of the range in the south Apennines. Although 21 taxa were described within this complex, only three, C. pyramidalis, C. versicolor, and C. secundiflora, have been generally accepted in recent synoptical taxonomic treatments. Our molecular phylogenetic analyses based on sequences of three non‐coding chloroplast regions (psbA‐trnH, psbZ‐trnfM, trnG‐trnS) as well as of nuclear ribosomal internal transcribed spacers (nrITS), lend strong support to the recognition of several lineages which only partially correspond to generally accepted taxonomic concepts. Molecular data presented in this study showed that C. pyramidalis is a polyphyletic assemblage that segregates into three distinct lineages, one of which is described here as a new species, C. austroadriatica sp. nov. The lectotype of C. pyramidalis, redefined in a strict sense, is designated. Neither C. versicolor nor C. secundiflora were found to be strictly monophyletic, but their monophyly could not be rejected. Morphological and biogeographical implications are discussed.

Although intraspecies researches within the black pine (Pinus nigra Arnold) have a long tradition, the intraspecies taxonomy, classification and chorology are still unclear. Among the numerous reasons that have caused this situation the most important are: the absence of a study that would completely cover the whole range of this species, the impossibility of connection of results of the existing detailed studies of certain areas, and the high variability of traits which have been used so far. Since the characteristics of the molecular systematic techniques could make possible the research free of the mentioned shortages, the intention of this study was to determine the relationships among nine populations of black pine using the random amplified polymorphic DNA (RAPD). The obtained results were compared to the recent results of the morphological and anatomical analysis of the leaves of the same populations. The RAPD results clearly divided the Croatian populations from populations of Austria (subsp. nigra) and Turkey (subsp. pallasiana), while among Croatian populations, as in previous study, the existence of several groups (subsp. illyrica, subsp. dalmatica and transitional population between them) was noticed. It is assumed that the optimisations conducted in this study will finally make possible estimating the relationships on the level of the whole range of the black pine and the classification based on molecular traits that are probably less dependent on environmental influences than it has been the case with the characteristics mostly used so far.

In this paper we have analysed invasive flora of Medvednica Nature Park, Croatia with respect to their origins, life forms, systematic positions, types of seed dispersal, Ellenberg indicator values and spatial distributions using MTB 1/64 grid units for analyses. A total of 27 invasive plant species, belonging to 14 families, were recorded with Asteraceae being the most frequently occurring family. Therophytes were the most common life form, as is generally true of Croatian invasive plants; however, hemicryptophytes and geophytes were more frequent in Medvednica. Here, invasive plants originated mainly from both Americas with slightly lower portion in comparison to all Croatian invasive plants, while contrary was the case when comparing those originated from Asia. The most widespread species was Erigeron annuus (L.) Pers., and the species with the lowest occurrence were Chamomilla suaveolens (Pursh.) Rydb and Datura innoxia Mill. A multiple regression model explains 44% of the spatial variability in the invasive plants data per MTB 1/64 unit, using the number of all recorded plant species, the average elevation and the lengths of paths and roads as estimators. The latter two variables also had the most influence on the ordination axes in analyses of the spatial distribution of seed dispersal types present in each MTB 1/64 unit. Anemochory was the most frequent type of seed dispersal.

In Croatia and the surrounding area, the genus Iris is represented with about 20 Alpine-Dinaric, Mediterranean and Pannonian taxa from the subgenera Iris and Limniris. We researched pollen morphology of all taxa by using scanning electron microscopy. All pollen grains are sulcate with few palynological features, which could have taxonomic importance on different classification levels: shape of dry pollen grains; shape, outline and approximate size of hydrated pollen grains, approximate size of the sulcus, and ornamentation of the sulcus membrane and of the exine. At least four pollen types were recognised and taxonomically delimited to the series level: two characterise the subgenus Iris, section Iris (series Elatae and Pumilae), and two the subgenus Limniris, section Limniris (series Laevigatae, Sibiricae and Spuriae). Taxonomic implications of pollen morphology of their critical groups and taxa have been evaluated. Possible phylogenetic implications of pollen morphology of the genus Iris on the Southern European area were suggested: the subgenus Iris is more advanced than the subgenus Limniris; I. graminea seems to be the most primitive member of the subgenus Limniris on the Southern European territory; and pollen morphology of the population of the subspecies I. sibirica subsp. erirrhiza from the Mountain Bjelolasica could represent a link between the subgenera Limniris and Iris in the territory of Southern Europe. The possible pathway of evolution of the genus Iris on the territory of Southern Europe was suggested: from the subgenus Limniris, through the “linked taxon” I. sibirica subsp. erirrhiza from the Bjelolasica Mountain, to the subgenus Iris, series Pumilae, and finally to the series Elatae.