Božena Mitić

Airborne pollen spectra at three sites in inland Croatia, 2003

The aim of this study was to determine whether there were major differences in the seasonal incidence and abundance of pollen grains and pollen types in pollen fall between sites of different land use. The material was collected from 5 January until 20 December 2003 at three sites in central Croatia. The sampling sites were located in an average urban setting (Zagreb), a rural setting (Ivanic Grad), and a small town surrounded by a large woodland with partially thermophilic vegetation (Samobor). Using the volumetric method of pollen collection, pollen grains of 35-37 taxa were identified, depending on the sampling site, eight of them producing the greatest amount of pollen (Alnus sp., Ambrosia sp., Betula sp., Carpinus sp., Poaceae, Quercus sp., Taxus/Juniperus, and Urticaceae). Differences among the sampling sites were recorded according to seasonal pollen concentration, total monthly pollen count, and total annual pollen count. The proportion of particular plant classes (tree, grass and weed) was quite comparable among the three sampling sites because of their relative geographic proximity (i.e. within the same climatic region). A difference was observed in the air pollen concentration. All three monitoring sites revealed the total annual airborne pollen concentration in inland Croatia to be dominated by highly allergenic pollen (Zagreb 54%, Samobor 58% and Ivanic Grad 82%) of the following taxa: Alnus sp., Ambrosia sp., Betula sp., Carpinus sp., Corylus sp., Poaceae, Urticaceae and Artemisia sp. Accordingly, there were no distinct phenologically induced differences in pollen species recorded at the three monitoring sites. However, substantial differences were observed in seasonal pollen grain count and in the percentage proportion of some allergenic pollen grains (Ambrosia sp., Betula sp., Carpinus sp., Poaceae), providing valuable information to individuals suffering from pollen allergy.

In vitro propagation of Inula verbascifolia (Willd.) Hausskn. subsp. verbascifolia

Abstract A clonal propagation method has been developed for Inula verbascifolia (Willd.) Hausskn. subsp. verbascifolia, a species of horticultural as well as potential medicinal interest. Shoots originating from aseptically germinated seeds were used for culture initiation. The highest multiplication rate of 6.5 shoots per explant was achieved in an 8-week culture period on Murashige and Skoog medium supplemented with 2.2 μM 6-benzylaminopurine and 2.9 μM gibberellic acid. During the first three subcultures of the multiplication phase, two-thirds of explants spontaneously rooted on all tested media. Rooting of excised shoots on MS medium supplemented with 3 μM IAA or 3 μM IBA was 100%. Aside from the fact that all the explants were rooted on this root-inducing media, explants developed a surprisingly high mean number of shoots, 4.6 and 2.9 after 4 weeks, on medium supplemented with IAA or IBA, respectively. Rooted plantlets were transferred to potting soil and acclimatized to outdoor conditions.

Invasive alien plants in Croatia as a threat to biodiversity of South-Eastern Europe: Distributional patterns and range size

During the analysis of alien and invasive flora of Europe, as a threat to biodiversity, data for Croatia were missing. The aim of our research was to analyse distributional patterns and range size of all invasive alien plants (64) for the state area (57,000 km(2)). They were detected on 49% of the state territory, averaging five taxa per 35 km(2). The greatest number of invasive plants (>30 per grid cell) was recorded in the major urban centres, increasing in the south-east direction and reflecting positive correlation with temperature and negative with altitude. The most endangered areas are in the Mediterranean region, especially on islands. The number of invasive plants increased with habitat diversity and almost 75% of all sites with invasive plants are located within a few habitats with direct anthropogenic influence. The results should provide a reliable regional and global basis for strategic planning regarding invasive alien plants management.

First aerobiological study in the Mediterranean part of Croatia (Dalmatia) : pollen spectrum and seasonal dynamics in the air of Split

The aim of this study was to investigate aerobiological dynamics of pollen in the Mediterranean part of Croatia in the air of the city of Split. Pollen monitoring during the period from 2005 to 2013 was performed using a Hirst volumetric trap. Among the identified pollen of 50 taxa, 21 were allergenic. The average annual pollen index was 33,513. Three pollination seasons were established: early winter season dominated by tree pollen, spring–summer season dominated by herbaceous plants and summer–autumn season with lower amounts of Parietaria and Cupressaceae pollen. According to the abundance, the main taxa were: Cupressaceae, Parietaria/Urtica, Pinus, Quercus, Olea, Carpinus/Ostrya, Poaceae, Platanus and Ambrosia. The annual pollen index together with the daily maximum concentrations showed an upward trend for selected taxa during the study period. The highest monthly pollen index and the highest biodiversity were recorded in April and the lowest during the late autumn and winter months. The pollen calendar created for the city of Split confirmed Mediterranean features of the pollen spectrum. The longest pollen seasons were recorded for Cupressaceae, Parietaria/Urtica and Poaceae pollen types. The correlations between pollen concentrations and meteorological parameters were analyzed. The correlations between pollen concentrations and temperature were positive, while the humidity and the precipitation mostly showed negative influence.

Diversity, knowledge and spatial distribution of the vascular flora of Croatia

The Balkan Peninsula is recognized as an important centre of plant diversity. Despite the fact that Croatia contains more than 50% of all Balkan species of vascular flora, the knowledge of the spatial distribution, α-diversity and relation to the conservation efforts have never been summarized and presented. A spatial analysis was performed on several data-sets containing a number of records and a number of species per grid cell. Results show that the Croatian flora consists of 4507 species and 1159 subspecies. The residuals around the linear regression used as a measure of the species richness indicate that Croatia had the highest residual value among the 40 European countries sampled and highest stress on the biodiversity value of the Apennine, the Iberian and the Balkan peninsulas. On the basis of half a million findings and their spatial distributions, we observed that within one grid cell (35 km2) 542 species could be expected. A number of records based on the herbarium specimens, literature and field observation and related spatial distribution were discussed. The spatial distribution of α-diversity indicates that the national hot spots were more consistent with the important plant areas network than with the network of officially protected areas.

Ecological characteristics of plant species and associations along two Dinaric karstic rivers (Bosnia and Herzegovina, the Balkans)

This paper describes the plant communities of two oligotrophic karstic rivers with a slight anthropogenic influence — the Trebižat and the Lištica — in South Bosnia and Herzegovina, their sinecology, and the relationship between vegetation and plant species and environmental parameters. According to 87 relevés, a total of 26 plant associations, using Braun-Blanquet methods, were found in the rivers and nearby surveyed area. Only nine associations were common to both rivers. Eight associations were recorded for the territory of Bosnia and Herzegovina for the first time. Associations from both rivers differed according to following parameters measured at the sampling site: water temperature, distance from the mouth (river kilometers), river width, water depth, flow, pH and slope. There were no differences in nutrient concentrations among the associations. According to Canonical Correspondence Analysis (CCA), three environmental variables out of the 11 initially considered were retained as being related to plant distribution. The first two axes explained 56.8% and 35.2% of variance of species-environment relationship in the Trebižat and Lištica rivers, respectively. Water depth in the Trebižat River, and pH and river kilometers in the Lištica River were found to be the most influential, while nutrients and other physico-chemical parameters were not significant in either river. Water depth vector was identified as an underlying environmental factor determining distribution of Potamogeton lucens and Myriophyllum verticillatum (Potamion), and Nymphaea alba (Nymphaeion albae). According to in situ measurements of light intensity, the highest coefficients of light attenuation, radiance and reflection were found at a station with dense populations of Potamogeton lucens and Nuphar luteum (Potametum lucentis). The vegetation and floristic value of the rivers is discussed as a basis for biodiversity conservation programmes and evaluating the state of these ecosystems in the future.

Pollen morphology of the genus Iris L. (Iridaceae) from Croatia and surrounding area: taxonomic and phylogenetic implications

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.

Orchid diversity of the cape of Kamenjak (Istria, Croatia)

Orchid diversity of the cape of Kamenjak (Istria, Croatia) Twentytwo taxa have been recorded in the south of Istrian peninsula (north Adriatic coast, Croatia). The research was performed in the period 2003-2004. A great majority of taxa belong to Euri-Mediterranean (seven taxa, 41.18%) and Steno-Mediterranean (six taxa, 35.29%) floral elements. Eurasiatic (two taxa, 11.76%), Atlantic (one taxa, 5.88%) and endemic (one taxon, 5.88%) plants were also present. Almost a half of recorded orchids are abundant or frequent. The most of taxa are endangered s.l.; nine vulnerable (VU) plants (52.94%), and one species endangered s.s. (EN) (5.88%). There are also near threatened (NT) (two taxa, 11.76%), and data deficient (DD) (one taxon, 5.88%) plants, while others have no category assigned (four taxa, 23.53%).

Echinochloa colona (L.) Link (Poaceae), a new species in the flora of Croatia

Abstract During floristic research into the eastern parts of Mt Medvednica (NW Croatia), in the period from 2007 to 2010, the neophyte taxon Echinochloa colona (L.) Link was found. Since E. colona is not included in plant identification handbooks, a new determination key for the two closely related taxa of genus Echinochloa, presented in Croatia, has been prepared, and the biology of this new alien plant is briefly discussed.

Taxonomic notes on Puccinellia teyberi (Poaceae), a critical species of Croatian flora

Puccinellia teyberi Hayek (Poaceae) is a critical species of the Croatian flora, described for the first time as Atropis rupestris Teyber from two small islets of central Adriatic Sea. Nomenclature, lectotypification, morphology, karyology, leaf anatomy, palynology, ecology and conservation status of this taxon are examined. According to these data, it must be treated as a distinct species, taxonomically related to P. convoluta and P. festuciformis. Besides, it represents a neoendemic apomictic species, confined to rocky costal places and having a punctiform distribution.