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The ceramialian genus Polysiphonia includes over 207 currently recognized marine species distributed along nearly all the coastlines of the Earth. It is primarily a marine macroalgal genus, with physiological mechanisms underpinning its tolerance to varying salinity. Polysiphonia subtilissima is the only species from the genus recorded in truly freshwater habitats, with three known records: (1) Juniper Creek, Florida, USA, North America ; (2) Jamaica, Caribbean Sea, Central America and (3) Pego-Oliva Natural Park, Spain, Europe. Molecular studies have confirmed that the freshwater populations are conspecific with the marine collections of P. subtilissima. The fourth freshwater record of this species is from the Neretva River Valley, a complex of wetland habitats in the Mediterranean part of Croatia, SE Europe. The alga covered solid submerged surfaces, mainly reed and other aquatic plants, from the surface to approximately 50 cm of depth at salinity levels ranging from 0.4 to 4.59 PSU. Vegetation surveys revealed coverage of P. subtilissima between 5 and 75 %, forming blooms in two sites: a river segment of 7 km and a wetland area of 70 ha. All populations were dense and associated with allochtonous tropical red alga Compsopogon caeruleus and invasive aquatic plant Myriophyllum heterophyllum. The most recent record from Croatia provides new insight into the species’ general distribution, spread into freshwater habitats and its ecological preferences.

Fourteen moss taxa were recorded for the first time in Croatia, many of which (Conardia compacta, Cynodontium tenellum, Dichodontium flavescens, Rhabdoweisia crispata and Schistidium trichodon var.trichodon) are of boreal-montane or (sub) arctic distribution, found in mountain areas of the country. Myurella sibirica can be considered a glacial relict in the western Dinarides, where particular microhabitat with specific relief and spring influence enabled its survival. The study of ephemerals of drawdown zones resulted in finding of a new species Physcomitrium eurystomum, confirmation of dubious Riccia cavernosa and R. frostii and new localities of rare Physcomitrella patens and Leptobryum pyriforme. Ricciocarpos natans was discovered in backwaters of Danube, Drava and Mura rivers. Finding of rare Natura 2000 hornwort Notothylas orbicularis, reported only from four Central European countries, is the first in southeastern Europe and the southernmost in Europe. Furthermore, we recorded Anthoceros agrestis and Phaeoceros carolinianus, rare or overlooked species in southeastern Europe. Aquatic Fissidens fontanus and Mediterranean epiphyte Orthotrichum philibertii were also new for country. Revision of Tortella bambergeri revealed neglected Tortella fasciculata in Croatia. New localities of rare Didymodon tophaceus subsp. sicculus, Ephemerum serratum, Mannia triandra, Oxystegus tenuirostris and Sphaerocarpos michelii were found. The further spread of invasive Campylopus introflexus was detected.

Plitvice Lakes are situated in Dinaric region of Croatia characterized by different karst formations. One of them is the system of 16 larger and several smaller cascading lakes, stretched 8 km in length and interconnected by numerous waterfalls of different size, height and water velocity. They are formed through the biodynamic process of growing tufa barriers in water oversaturated with calcium carbonate, pH value higher than 8 and low concentration of dissolved organic matter. All these tufa barriers are overgrown by rich vegetation dominated by bryophytes. This vegetation was studied using phytosociological methods followed by measurements of environmental parameters and analysis of ecological indicator values. In total 44 bryophyte species were recorded of which 26 are constantly present in 90 vegetation relevés. The main characteristics of vegetation are r vascular plants and very constant species composition with a low number of species present with high abundances. Four main species are Palustriella commutata, Eucladium verticillatum, Hymenostylium recurvirostrum and Pellia endiviifolia. Nevertheless, three main types of bryophyte vegetation are differentiated – species poor vegetation of non-shaded waterfalls mostly with high water velocity, the vegetation of shaded waterfalls with weaker water flow, and species rich vegetation of moist rocks outside direct or constant influence of running water. All of these vegetation types belong to the moss rich vegetation of carbonate springs of montane and subalpine belts of Europe belonging to the alliance Cratoneurion commutati. However, due to the complex system of lakes and waterfalls, very large surfaces covered by this vegetation, species richness and their high abundances, Plitvice Lakes represent one of the most important diversity and distribution centres in Europe regarding the tufa forming bryophyte vegetation and is of the highest conservation value.

During vegetation seasons 2016 and 2017 macrophyte vegetation of 36 (21 in Dinaric and 15 in Pannonian ecoregion) artificial water bodies – reservoirs and accumulations was studied in order to get insight into macrophyte diversity and to develop assessment method for water quality using macrophytes according to EU Water Frame Directive. The vegetation was surveyed using transects positioned perpendicular to the bank and stretched to the depth limit of macrophyte occurrence. Extended, nine-degree, Braun-Blanquet scale was used for estimation of species cover-abundance. Physico-chemical and hydromorphological parameters were also included in analyses. In total, 110 species were recorded with very uneven distribution. High water level fluctuations are the most limiting factor for macrophyte occurrence, followed by water turbidity and some chemical parameters. For estimation of ecological classes of water quality, reference index was developed based on system of indicator species (indicators of good status and referent species, indifferent species and indicators of degradation). It was shown that reference index is significantly correlated with environmental parameters and therefore can be used as measure of water quality. In general, artificial water bodies in Dinaric ecoregion have higher macrophyte diversity and higher water quality i.e. ecological status in comparison to those in Pannonian ecoregion.

U elaboratu se iznose i komentiraju rezultati godišnjeg istraživanja fizikalno-kemijskih, bioloških i ihtioloških značajki nadzemnih voda rijeke Drave na području utjecaja hidroelektrana Varaždin, Čakovec i Dubrava tijekom 2018. godine.

Genus Ulva Linnaeus (Ulvophyceae, Ulvales, Chlorophyta) is a cosmopolitan macroalgal genus commonly known as „sea lettuce“. It comprises species living in different aquatic environments, however represents the most frequent coastal seaweed world-wide. Nevertheless, since the mid 1800’s Ulva is being observed in European inland waters as well. At the beginning of the 21st century, massive occurrences of Ulva flexuosa have been noted in European lakes, ponds and rivers, making the genus an obvious dominant element in these waterbodies. In Croatia, a number of specimens involving Ulva (including former Enteromorpha) have been recorded in inland freshwater and brackish sites of northern and middle Adriatic, casually and erroneously described as Enteromorpha intestinalis (Linnaeus) Nees (=Ulva intestinalis) and E. salina Kützing (=U. prolifera). Intrigued by the observed ingress of sea taxa towards freshwaters, we collected specimens from freshwater sites along Eastern Adriatic coast in Croatia while conducting the monitoring of macrophytes. Additionally, macrophyte vegetation surveys were performed and physico-chemical parameters were measured in situ or by Central Water Management Laboratory. In the period 2016-2018 Ulva flexuosa has been recorded in Raša, Mirna, Zrmanja, Cetina rivers, water bodies in the Neretva River Delta and in freshwater spring on the island of Krk. In these locations, salinity ranges were from 0 to 18 PSU, while species occasionally occurred in massive blooms and undoubtedly formed significant habitats in the form of rooted or floating aquatic vegetation. These findings mark the first data about occurrence of U. flexuosa in Croatian fresh and brackish waters.

Despite the fact that Croatia is bryologically one of the most explored countries of former Yugoslavia and Southeastern Europe, the data are to a large extent spatially and temporally biased. Beginning in the first decades of the 19th century, the research had the highest peak at the end of the 19th and at the beginning of the 20th century, intensified again in the 1950s and 1960s, followed by the almost complete absence of any bryological work until 2009. Thenceforward, during the last 10 years, mainly owing to cooperation between the Hungarian Natural History Museum and the University of Zagreb (Croatia), 58 new taxa were discovered as new for Croatia. Apart from this, in order to summarise all historical literature and herbarium data, a publically available database with nearly 31.000 geocoded spatio-temporal entries has been established. Concluding, at the current state of knowledge, Croatian bryoflora includes 789 taxa - 606 mosses, 178 liverworts and five hornworts. Future studies should be focused on (1) Croatian regions with lack of bryological data, (2) many taxa with single and very old records and (3) threatened species and species of conservation value.

The bryophyte flora in the settlement Selina and the surrounding area (western Istria) was surveyed during the vegetation season of 2014. Altogether 66 mosses and 6 liverworts were recorded. Phytogeographically, the most abundant species are of the temperate zonobiome, i.e. circumpolar species, with respect to eastern limit categories. Analysis of bryophyte flora through habitat types shows that the highest species richness occurs by shaded rocks and in crevices, while the lowest richness occurs on arable land and occasionally the flooded banks of ponds. Regarding species composition, habitat types are clustered in four basic groups. Based on Ellenberg’s ecological indicator values for light, moisture, reaction of substrate and amount of nutrients, the differences between bryophyte floras of different habitats are explained using methods of descriptive and multivariate statistics.

Mediterranean coastal and islands region abounds in small and shallow, mainly temporary freshwater ponds which have been rare subject of a scientific topic for a long time. They represent unique habitats in dry and arid climate inhabited numerous species, especially invertebrates with a short life cycle and can be rapidly colonized during the flooding season. Impact of benthic invertebrate predators and fish on zooplankton was assessed in the island freshwater ponds (island Korčula), and this is one of the first data for these habitats in the eastern Adriatic coast. The goals of this study were to investigate: i) interaction among benthic invertebrates, fish and zooplankton ; and ii) difference in shelter selection, bottom sediment vs. macrophytes. Analysis of ecosystem functioning shows decreased abundance of planktonic crustaceans in ponds with low macrophyte coverage, and vice versa, which highlighted role of macrophyte for zooplankton refuge against predators (acari, heteropterans, fish). Results suggest that macrophyte can serve as shelter for zooplankton, but in the case of high macrophyte abundance and numerous benthic invertebrate predators, role of macrophyte shelter is diminish, and zooplankton probably found refuge in sediment. This is confirmed by increased abundance, especially cladocerans, in the sediment. Through the dual impact of predators and low macrophyte coverage, as well as huge impact of benthic invertebrates among macrophytes, sediment was an efficient refuge for zooplankton. Interaction between predators (benthic invertebrates and fish) and zooplankton displayed higher complexity along habitat heterogeneity, while zooplankton share an important fraction in food resources among the trophic network.

Neretva River Delta is a marshland area situated in southern Dalmatia, encompassing the last 20 km of the river, together with a network of surface water bodies, which are well interconnected due to the long-term human influence and interventions into the landscape. Previous studies revealed over 800 plant taxa in the Delta, however no systematic study of waterbodies was ever performed. In this study, we have focused on mapping two alien aquatic plants Egeria densa and Myriophyllum heterophyllum along the waterbodies in the Delta, by performing a systematic and comprehensive fieldwork. We have recorded a large number of new localities of these aliens and observed populations displaying invasive behaviour. Apart from the targeted species, we have recoded 62 mostly aquatic plants. Altogether eight threatened taxa were recorded: critically endangered (CR) Dorycnium rectum and Hydrocotyle vulgaris, endangered (EN) Cynanchum acutum, Hippuris vulgaris, Hottonia palustris, Periploca graeca and Ranunculus lingua and vulnerable (VU) Cyperus longus. Near threatened (NT)Butomus umbellatus and data deficient (DD) Utricularia australis were also recorded. The species Hydrocharis morsus-ranae and Nymphoides peltata, not previously known from the Mediterranean Croatia apart from one and two historical records from Neretva, were found on many sites during this study. Similarly, we have recorded Sagittaria sagittifolia and not previously known from Mediterranean Croatia and Hottonia palustris and Thelypteris palustris previously recorded in Dalmatia only once. A rare species Cladium mariscus was also recorded, as well as a very rare moss Riccia fluitans, previously known only from very few localities in continental Croatia.

The bryophyte flora in the settlement Selina and the surrounding area (western Istria) was surveyed during the vegetation season of 2014. Altogether 66 mosses and 6 liverworts were recorded. Phytogeographically, the most abundant species are of the temperate zonobiome, i.e. circumpolar species, with respect to eastern limit categories. Analysis of bryophyte flora through habitat types shows that the highest species richness occurs by shaded rocks and in crevices, while the lowest richness occurs on arable land and occasionally the flooded banks of ponds. Regarding species composition, habitat types are clustered in four basic groups. Based on Ellenberg’s ecological indicator values for light, moisture, reaction of substrate and amount of nutrients, the differences between bryophyte floras of different habitats are explained using methods of descriptive and multivariate statistics.

Istraživanje je obuhvatilo inventarizaciju mahovinske i vaskularne flore te vegetacije Spomenika prirode Vrelo Une. Specifična kombinacija submediteranskog krša i izvora omogućila je stvaranje lokalnog centra raznolikosti biljnih vrsta i staništa na vrlo malom prostoru u kojem se susreću utjecaju dvaju vegetacijskih pojaseva.

Cilj istraživanja bio je zabilježiti odabrane kopnene invazivne biljne vrste u području Delte Nertve, te procijeniti veličinu njihovih populacija. Zabilježeno je 46 invazivnih svojti, od kojih čak 16 po prvi puta na ovom području. Najveći broj svojti ima točkaste populacije (manje od 10 kvadratnih metara), dok samo pojedine svojte formiraju populacije značajne veličine. Utvrđeno je da istraživane vrste dolaze u čitavom području Delte, no najveći broj nalaza je u područjima i na staništima pod izraženim ljudskim utjecajem.

The Plitvice Lakes represents a system of 16 larger and several smaller cascading lakes interconnected by numerous waterfalls. All these tufa barriers are overgrown with dense vegetation, which was studied using phytosociological methods. In total 44 species of bryophytes and 52 vascular plants were recorded, out of which 26 bryophytes and 40 vascular plants are constantly present in 90 vegetation relevés. The vegetation is mainly characterized by dominance of bryophytes over vascular plants, and constant species composition. Four main bryophyte species are Palustriella commutata, Eucladium verticillatum, Hymenostylium recurvirostrum and Pellia endiviifolia. The most abundant and constant species of vascular plants is Petasites kablikianus, present in almost all vegetation plots. This species occur only in the Plivice Lakes within Croatia, which make this vegetation unique and peculiar. Nevertheless, three main types of vegetation are differentiated: 1) species poor vegetation of non-shaded waterfalls mostly with high water velocity, 2) vegetation of shaded waterfalls with weaker water flow, and 3) species rich vegetation of moist rocks outside direct or constant influence of running water. All these vegetation types belong to the moss rich vegetation of carbonate springs of montane and subalpine belts of Europe, belonging to the alliance Cratoneurion commutati. However, due to the complex system of lakes and waterfalls, very large surfaces covered by this vegetation, species richness and their high abundances, Plitvice Lakes represent one of the most important diversity and distribution centres in Europe regarding the tufa vegetation, and are of the highest conservation value.

The aim of this study was to collect and analyse data on aquatic plants within the Herbarium Croaticum (ZA), the largest and oldest herbarium collection in Croatia. In total 951 herbarium sheets representing 72 aquatic taxa were renovated, digitized, geo-referenced (generating distribution map for each taxa)and made publically available in Flora Croatica Database and Virtual herbarium of ZA & ZAHO. Aquatic plants within ZA collection have been collected during the period of 165 years, the oldest sheet originates from as early as 1844, while the average age of herbarium sheets is 76 years. The most abundant genera are Potamogeton and Ranunculus, whereas most common families are Potamogetonaceae and Ranunculaceae. Most of the specimens were collected in Croatia, and smaller part in neighbouring and geographically close countries (Slovenia, Hungary, Serbia, Bosnia & Herzegovina, Montenegro, Italy, Austria and FYR Macedonia). As much as 28 Red listed aquatic taxa are stored within ZA collection. The importance of collection is expressed through specimens of many rare and threatened species, for which this collection represents the only evidence of their presence in Croatia (regionally extinct Caldessia parnassifolia, as well as Luronium natans, Callitriche platycarpa, C. truncata, C. hermaphroditica, Potamogeton alpinus, P. polygonifolius, Scheuchzeria palustris, Rynchospora fusca, Myriophyllum alterniflorum, Nuphar × spenneriana and Sparganium minimum). Collection of aquatic plants in ZA is important source of data considering their historical and recent distribution, which are the basis for estimation of distribution changes, threat evaluation and protection planning.

U sklopu projekta provedeno je detaljno istraživanje flore i vegetacije sedrenih barijera u čitavom sustavu Plitvičkih jezera.

Vaccinium myrtillus L., Ericaceae (bilberry) leaf is traditionally used in southeastern Europe for the treatment of diabetes. In the present study, the variation of the phytochemical composition, antiradical and tyrosinase-inhibiting activity of 11 bilberry populations from Croatia (5) and Montenegro (6) was investigated with the aim of their use for cosmetic purposes. Content of phenols, flavonoids and phenolic acids, as well as antiradical and enzyme inhibiting activity of leaf extracts was determined spectrophotometrically. The content of the most abundant flavonoid, hyperoside, was determined using HPLC with DAD detection. Furthermore, the content of selected metals (K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr) was determined using TXRF. Outstanding quantitative variability of total phenols (386.8 – 133.9 mg/g), flavonoids (83.1-12.0 mg/g) and phenolic acids 112.4-38.0 mg/g) was recorded. The extracts displayed excellent antiradical activity (IC50 between 120.8-11.1 g/g) and somewhat weaker anti-tyrosinase activity (IC50 between 400.3-170.9 g/g). Hyperoside content in the extracts varied between 73.1 and 5.7 mg/g. There were no statistically significant differences between the measured variables according to the country of origin. However, the chromatograms of Montenegro extracts could be easily distinguished from the Croatian ones by the presence of additional peak in chromatogram, which, according to its UV spectrum, belonged to a quercetin derivative. The observed activities of bilberry leaf extracts suggest that they might be used in cosmetic products. However, before the development of such products, a detailed analysis of plant material is advisable in order to select the populations with the highest potential activity.

Sedrene barijere su jedan od temeljnih fenomena rijeke Krke. Projektom su obuhvaćene sedrene barijere na čitavom toku rijeke, odnosno svih sedam sustava slapišta (Bilušića buk, Brljan, Manojlovac, Rošnjak, Miljacka, Roški slap, Skradinski buk). Na osnovu 53 vegetacijske snimke utvrđena su tri osnovna tipa zajednica. Flora i vegetacija sedrenih barijera Krke dobro su strukturirane i bogate vrstama što upućuje na njihovu prirodnost i očuvanost.

Cilj istraživanja bio je utvrditi pristnost algi parožina u Parku prirode Vransko jezero, njihovu pokrovnost te promjenu u sastavu vrsta i pokrovnosti u odnosu na prethodna istraživanja od 2010.-2014. te u 2018. Uzorkovanje je obavljeno na 42 ranije definirana lokaliteta u jezeru i okolnim kanalima. Predstavnici skupine zabilježeni su na 33 lokaliteta, najčešće vrste bile su Chara intermedia i Nitellopsis obtusa. Stanje populacija algi parožina u 2019. godini u Vranskom jezeru pokazuje trend održavanja stabilnosti populacija s malim promjenama u prostornoj rasprostranjenosti pojedinih vrsta i blagom padu ukupne pokrovnosti. Zaključno, u 2019. godini je zastupljenost algi iz porodice Characeae procijenjena na oko 80 % jezera.

Grasslands stretch mainly along the edge parts of Medvednica Nature Park, where numerous ecotones are formed in contact with forest edges and shrubs vegetation. Although covering only 1.81% of the Park's surface, they contribute significantly to the landscape diversity and are important as habitats of many species that are relevant for protection. The aim of the first research was to determine the grassland types and their degree of overgrown within the Park. The survey was carried out in 2010 on a total of 49 localities, including the vegetation images production using the standard Braun-Blanquet method, as well as data on exposure, incline and habitat utilization. The results identified four basic grassland groups and so-called high green, and within each group two communities and several of their succession stages can be distinguished. By abandoning the villages and traditional use of space such as grazing and mowing, the development of successive vegetation of woody and bushy species has begun to change habitats. The most valuable and most endangered is the thermophilic dry grassland type with upright bromegrass in the wider Čučerje area as the only remaining finding site of Anemone Sylvestris species in Croatia. Because all of this, the employees of the Public Institution have regularly visited and evaluated the condition of flora and grassland habitats in recent years. Further research and introduction of flora and other components monitoring is essential for effective grassland management planning and the introduction of active management measures.

Lake Visovac is situated in Krka National Park and it represents the largest extension of Krka River. In summer 2018 the line transect sampling method was applied for vegetation mapping. In total 21 transcts perpendicular to the shore up to the depth at which the macrophytes cease to appear were made, generating as much as 293 species/location records. In total, 26 species of aquatic plants was found, including one yellow-green algae, eight charophytes, two mosses and 15 vascular plants. The most common species in the flora of Lake Visovac are Myriophyllum verticillatum, Najas marina, Phragmites australis and Potamogeton perfoliatus. Discovery of a rare aquatic moss Fissidens fontanus is of great importance, being the second in Croatia. There are four main vegetation belts in the aquatic vegetation of Lake Visovac: helophytic (dominantly reed) vegetation, submerged vegetation with or without floating leaves (belonging to NATURA 2000 habitat type 3150 Natural eutrophic lakes with Magnopotamion or Hydrocharition) and charophyte vegetation (NATURA 2000 habitat type 3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara spp.). Lake Visovac is dominated by plants of light, warm habitats which survive unfavorable living conditions with their buds in water and which prefer supstrata rich in nutrients and water with neutral pH and low salinity. The increased inlet of nutrient rich water and the anchoring represent the main threats to the preservation of Lake Visovac vegetation.

U elaboratu se iznose rezultati monitoringa travnjaka NP Sjeverni Velebit na koje nakon nekoliko desetljeća izostanka, ponovno vraćena ispaša govedima. Istraživanje je obuhvatilo kompleks sljedećih travnjaka: Veliki Lubenovac, Tudorevo, Šegotski padež, Bilenski padež, Dundović-Mirovo i Barićević Dolac. Izrađivane su vegetacijske snimke prema standardnoj srednjoeuropskoj metodi, te su napravljeni prostorno-vremenski prikazi kretanja stoke tijekom vegetacijske sezone. Detaljno je analizirana dostupna literatura o demografskim kretanjima u 20. i 21. stoljeću na području Parka i područja koje mu gravitira (Podgorje), te podaci o broju stoke.

Ephemeral bryophytes are short-lived species that can germinate and finish their whole life cycle within a brief period when favourable conditions occur. A significant number of these specialist species are associated with moist and finetextured substrata of the margins of lakes, reservoirs and rivers, also known as drawdown zones. Our study of the vegetation of drawdown zones, the first focusing on these specific habitats in Croatia, resulted in significant records for Croatian bryoflora ; a new species (Physcomitrium eurystomum), confirmation of two species, the occurrence of which was doubtful (Riccia cavernosa and R. frostii) and new localities of two extremely rare species (Physcomitrella patens and Leptobryum pyriforme). Although these species and their habitats are considered relatively rare and threatened in Europe, the low number of records in Croatia is to a considerable extent the result of there having been insufficient research into ephemeral habitats and the bryophyte flora in general.

Large areas of National park "Krka" used to be covered with dry rocky grasslands, used for centuries as pastures and maintained by permanent coppicing and occasional burning. The abandonment of this traditional land use in the second half of the 20th century caused major changes through encroachment of pastures by shrubs and trees. The aim of this study was to understand the dynamics of plant recolonization on grasslands and provide a sustainable model for habitat maintenance by monitoring the effects of controlled fire. Two closed transects of eight and nine 10 × 10 m subplots were regularly monitored three times a year, starting from 2015, before first burning, using Braun-Blanquet extended scale. The results have shown that in the first year after the fire, the vegetation structure is unstable exhibiting “non interactive species equilibrium”, when annual ruderal species prevail in flora composition. However, during second and third year “interactive species equilibrium” was established, when typical grassland species start to dominate and the number of species drastically increased in comparison to the pre- fire condition. Simultaneously, deciduous shrubs and trees started to recover from the underground plant parts. In contrast, Juniperus oxycedrus and Pinus halepensis do not show such renewal, but establish exclusively from new seedlings. Interestingly, there is also high variability in recolonization and flora structure with respect to previous plant cover, e.g. the slowest recolonization rate is evident at the spots of burnt juniper shrubs, where grass species show remarkably poor ability to enter this microhabitat.

According to the Flora Croatica Database, Croatian flora so far includes 5722 plant taxa, which is a rather high number considering the corresponding area. Although the distribution of the majority of taxa is well documented, rare taxa are often poorly known. Native rare taxa are most commonly documented in historical literature, while recent data are absent or very scarce. Alien taxa may be rarely recorded due to the short residence time, or low speed of spread. Within the course of different botanical studies, we have encountered some of the rarely documented plants such as Frankenia pulverulenta L., Vincetoxicum fuscatum (Hornem.) Rchb. f., Quercus trojana Webb, Lemna minuta Kunth, Reynoutria sachalinensis (F. Schmidt) Nakai, Sporobolus pungens (Schreb.) Kunth, Veronica peregrina L., Crocus thomasii Ten. and Petasites kablikianus Tausch ex Bercht., gaining new insight into their occurrence in Croatia. These findings are of great importance for the conservation of rare natives, and early detection and better understanding of spread of rare aliens. Given that loss of biodiversity starts with rare species, specific studies and continuous field searches and visits to historical localities of rare taxa are needed in order to keep the track of the status of Croatian plant diversity.

Hornworts are quite inconspicuous ephemeral bryophytes mostly inhabiting transient but regularly recurrent habitats subjected to yearly disturbances, such as arable and stubble fields with loamy and clayey soils. Globally, they are the least diverse group among bryophytes regarding the species number. Similarly, only four genera with eight species are known from Europe, five of which were reported from Southeast Europe. Only Phaeceros laevis (L.) Prosk and Phymatoceros bulbiculosus (Brot.) Stotler, W. T. Doyle et Crand.-Stotl. are listed in the available literature for Croatia ; however, with no new records for over 85 years in the case of P. laevis, and 100 years in the case of P. bulbiculosus. Our study, carried out in April 2013 and August 2018 in Central Croatia and focusing on the habitats suitable for hornworts, identified three new species for Croatia, including two new genera – Notothylas and Anthoceros. Record of very rare Natura 2000 species Notothylas orbicularis (Schwein.) A. Gray is the first in Southeast Europe and the southernmost in Europe, with previously known localities from only four Central European countries. Furthermore, we recorded Anthoceros agrestis Paton and Phaeoceros carolinianus (Michx.) Prosk., which are either very rare or, more likely, overlooked and understudied in Southeast Europe. Additionally, available data on hornworts from the literature and herbaria were examined and countrywide overview of the whole group is provided. Finally, these findings increase the richness of Croatian bryophyte flora to 711 taxa - 544 mosses, 162 liverworts and five hornworts.

Bilberry (/Vaccinium myrtillus/, Ericaceae) fruit is one of the most appreciated berries, not only for its dietary importance but also for its medicinal value. Furthermore, due to the abundance of natural polyphenols bilberry leaf has important medicinal potential and it is traditionally used in southeastern Europe for the treatment of diabetes[1]. It has been postulated that this activity may be due to the presence of chromium, an important factor for enhancing insulin activity. Furthermore, the leaf is often collected in the wild and herbal material may be contaminated with heavy metals such as mercury, arsenium, cadmium and others [2], whose presence would negatively affect the consumers health. Since the presence of chromium and other heavy metals is strongly related to environment where the plant grows, the aim of this work was to assess the levels of these metals in plant material collected in several locations in Croatia and Montenegro, where the leaf is usually utilized.

Effects of pollutants in the environment may be well estimated by using bioindicators suitable for indicating pollution according to their occurrence, frequency, abundance, vitality and changes in responses under certain environmental conditions. Mosses are commonly used as indicators of heavy metal (HM) pollution because of their specific morphological and physiological properties. The unique positions of Risnjak National Park (RNP) on the geomorphological boundary between the coastal Mediterranean part of Croatia and the continental hinterland have evidently caused a considerable atmospheric fallout impact on their soil cover. The aim of research was to evaluate the atmospheric deposition of the HM (Cd, Cr, Hg, Pb and Zn) by using Hylocomium splendens (HS) and Brachythecium rutabulum (BR) species of pleurocarpous mosses, which natively grows in the RNP. Mosses were collected during dry and rainy period in 2016 from 5 sampling sites of RNP. Mosses tissue samples were analyzed for Cd, Cr, Hg, Pb and Zn. Data suggest that mosses are more favorably exposed to the atmospheric deposition of contaminants than the soil surface thus enabling the use of mosses as effective bioindicators of metal atmospheric deposition. Conclusions: i) BR is possibly more suitable for biomonitoring of atmospheric metal deposits than the HS ; ii) higher concentrations of all investigated metals were measured at almost all research locations in moss BR and iii) higher concentrations of long-range transported HM (Cd, Pb and Zn), also recorded in BR.

Alnus alnobetula (Ehrh.) K.Koch (Betulaceae) is a monoecious and wind-pollinated, relatively short-lived, medium-sized deciduous shrub with a circumpolar distribution. The green alder comprises five subspecies, of which subsp. alnobetula (= A. viridis (Chaix) DC.) is native to Central, Southern and Eastern Europe. In Croatia, at present it can be found at only one locality on the Žumberak Mt (NW Croatia). The area of its distribution is restricted to the right slope above the Sušik brook, where it grows on moist soil alongside the Sekulići-Sv. Gera road. In this study, we evaluate the morphological variability of the green alder in Croatia. In October 2017, plant samples, i.e. leaves from two different types of shoots (short and long), male catkins, and infructescences (fruiting catkins), were collected for morphometric analysis. Descriptive and multivariate statistical methods were used to examine the diversity. The mean values of characters describing the size and shape of the leaves, as well as those describing male and fruiting catkins are similar to those reported in literature. In addition, our analyses have shown that the leaves from short shoots in comparison with the leaves from long shoots have a smaller leaf blade area, shorter petioles, and more rounded leaf base. Morphological variability is moderate, and significant intra-population variability has been observed for all analysed traits. Nevertheless, the low number of individuals, and large‐scale habitat changes (i.e. vegetation succession caused by abandonment of traditional land use and possible changes in water supply) would lead to the decline of the green alder population in Croatia. Because of its rarity, uniqueness, and scientific and conservational importance, the green alder in Croatia deserves special conservational measures and protection. Ecosystem management practices required to ensure the conservation of this rare and locally threatened woody plant species in Croatia are discussed in this paper.

The flora of the minute islet of Mrduja (1.3 ha), located between the Middle Adriatic islands of Brač and Šolta, was studied in 2017, resulting in the recording of 63 taxa of vascular plants and six bryophytes. The predominance of the Poaceae (13%) and Fabaceae (8%), terophytes (30%) and Mediterranean floral elements (73%) clearly demonstrates the Mediterranean phyto-geographical position of the islet. Nearly one third of taxa were found on anthropogenic habitats, even though they are exceptionally rare on the islet, proving that even a slight human presence can have a profound influence on the flora of an island., Tijekom 2017. provedena su istraživanja vaskularne flore i flore mahovina otočića Mrduje (1.3 ha), smještenog između srednjodalmatinskih otoka Brača i Šolte. Utvrđene su 63 svojte vaskularne flore, te šest svojti mahovina. Dominacija porodica Poaceae (13%) i Fabaceae (8%), terofitskog životnog oblika (30%) i mediteranskih flornih elemenata (73%) jasno ukazuje na mediteranski fitogoegrafski položaj otočića. Gotovo trećina svojti zabilježena je na antropogenim staništima koja su vrlo rijetka na otočiću, što dokazuje da čak i slaba prisutnost ljudi može značajno utjecati na floru otoka.

Mountais are among the most sensitive ecosystems to climate change and are being affected at a faster rate than other terrestrial habitats. Mountains therefore represent unique areas for the assessment of climate-related impacts, including long- distance transport of air pollutants. Mosses serve as effective bioindicators of air quality because of their high surface-to-volume ratio and a very thin cuticle. In this study, we investigated variations in atmospheric heavy metal deposition across an elevation gradient in the Risnjak mountain region using mosses as bioindicators. The capacity for heavy metal accumulation was compared between two species, Brachythecium rutabulum and Hylocomium splendens collected during rainy and dry seasons in 2016, from 5 sampling sites at 350 to 1450 m elevation. Cd, Cr, Pb and Zn were analysed by inductively coupled plasma optical emission spectroscopy (HRN ISO 22036:2011), while Hg was analysed by cold-vapor atomic absorption spectrophotometry (HRN ISO 16772:2009). The Cd concentration ranged from 0.2 to 0.58 mg kg−1, Cr from 0.6 to 27 mg kg−1, Hg from 0.036 to 0.136 mg kg−1, Pb from 3.0 to 8.2 mg kg−1, and Zn from 8.6 to 82 mg kg−1 of dry tissue weight. The highest concentrations of heavy metals were measured in B. rutabulum, especially in the samples collected during the rainy season at higher altitudes, which can be related to more intensive deposition of metals from the atmosphere due to higher precipitation rates in the period before sampling.

Ephemeral bryophytes are short-lived colonists that can germinate and finish their whole life cycle within a brief period during the vegetation season when favourable conditions occur. A significant number of these specialist species are associated with habitats such as margins of lakes, reservoirs and rivers. While conducting the national monitoring of the surface waters in 2016 and 2017 natural and artificial water bodies throughout Croatia were surveyed and water margins were inspected for eventual ephemeral bryophytes. We recorded a new species for the bryophyte flora of Croatia - Physcomitrium eurystomum Sendtn. on the margins of the Lake Biljsko Jezero, an oxbow lake of the Drava River near Osijek. Furthermore, a rare ephemeral species Physcomitrella patens (Hedw.) Bruch & Schimp. Was confirmed for the flora of Croatia. Physcomitrella patens grew in the drawdown zone of the Lake Biljsko Jezero, the Kruščica Reservoir in Lika, the Lake Sakadaš in Baranja and three rivers in Moslavina – Rajić, Ilova and Trebež. During our research rare ephemeral species Riccia cavernosa Hoffm., R. bifurca Hoffm., R. fluitans L. and Leptobryum pyriforme (Hedw.) Wilson were also recorded. Although mentioned species and their habitats are considered relatively rare and threatened in Europe, the low number of records in Croatia is to a considerable extent the result of insufficient research done into ephemeral habitats and bryophyte flora in general.

The most recent check-lists of Croatian bryofl ora were published more than a decade ago (15 years ago for hepaticae, and 12 years ago for mosses). More recently however, major progress was made in the research of Croatian bryofl ora, with many signifi cant contributions in the fi eld up to date. Th erefore, the need to critically revalue the existing lists, and prepare a new list to be incorporated into the Flora Croatica Database (FCD) occurred in recent times. For this purpose, we analysed all available literature about the Croatian bryofl ora, with a special emphasis on old, 19th century literature that was partly omitted from the existing check-lists. Additionally, we have analysed the collection of bryophytes from the Hungarian Natural History Museum. As a result, we have added approximately 25000 literature and 6000 herbarium records into the FCD, creating a list of altogether 782 taxa. Finally, the FCD continues to be regularly updated with additional data from ZA and ZAHO herbarium collections, which includes adding the photographs and synonyms of corresponding taxa.

Grey alder (Alnus incana (L.) Moench) is an European species distributed across central, northern and eastern Europe up to the Caucasus. Contrary to its more widespread congener, the typical lowland common alder (Alnus glutinosa (L.) Gaertn.), grey alder is more common in higher elevations, up to 1400 m, where it mostly forms stands alongside alpine rivers, brooks and other humid habitats. Its communities were recently studied on the European level from the point of phytosociology, but questions about phytosociological diversity, biogeography and relationships to other parts of Europe remained open, since the whole Balkan area was underrepresented in this study. Namely, most of previously published data were written in national languages and published in hardly accessible local journals, representing “grey information”, oft en neglected in modern studies. Th erefore, the aim of our study was to use our recent fi eld researches and investigate the published data more thoroughly, to fi ll this gap. Stands from the south-eastern Dinarides were analysed and compared with the ones from the north-western Dinarides. Th e comparison revealed signifi cant diff erences in the fl oristic composition and the degree of diff erentiation, particularly regarding the presence of the Illyrian fl oristic geoelement. In total 198 relevés were analysed based on fl oristic composition and grouped in four main clusters, out of which three are confi ned to the north-western Dinarides, showing that this is the centre of diversity of Dinaric grey alder phytocenoses. For each cluster, characteristic and diff erential species were estimated, clearly defi ning the ecological and phytogeographical diff erentiation of these phytocenoses. However, further research is inevitable in order to gain a more detailed picture of the characteristics, diversity and relationships between Dinaric stands of grey alder.

During 2017, the indigenous flora of the Bregana settlement in northwestern Croatia was studied. The floristic data available for this area, covering 2.8 km², are sparse, and this study recorded a total of 232 taxa of vascular flora from 178 genera and 75 families. The most common plants belong to the family Asteraceae s.l. (14.4%), Lamiaceae (7.5%), Fabaceae (7.5%), Ranunculaceae (5.1%), Rosaceae (4.6%) and Poaceae (4.6%). The ratio of floristic elements places the study area in the Euro-Siberian/North American region, in the zone of the Central European deciduous forests, with the presence of numerous southern, thermophilic elements, while the species of the Illyrian-Balkan elements indicate a long continuity of those forests, and gives a local distinctiveness to the flora. The presence of Mediterranean, Eastern European and Eastern European/Pontian elements indicates the long-lasting anthropogenic influences. In the spectrum of life forms, the hemicryptophytes are dominant (53%), followed by the phanerophytes and geophytes (15.1%) and therophytes (11.6%). In terms of the IUCN categories of threat, one species is classified as endangered, one as vulnerable, six as near threatened and two as least concern. A total of 29 alien species were also identified, and of these ten are considered invasive.

First “tips” about the macroalgal flora in Croatian freshwaters were provided during mid- and late-19th century, in the form of the observations of certain species of Chlorophyta, Rhodophyta and Chrysophyta in karst watercourses. During the mid-20th century, there was a major breakthrough in this topic when a large number of papers dealing with the occurrence and abundance of algal flora in the watercourses of Dinaric ecoregion was published. Great deal of these papers was published as offprints, on local language in local journals, only available in printed forms ; while only a small number is scanned and available online. In addition, online scans often do not appear in traditional internet search engines, because they do not contain digital keywords recordings but are saved as textual photographs. Between these historical records and recent studies of freshwater algae, there was a large gap of surveys and publishing covering this topic in Croatia. Recent research dating from the begging of 21st century is mostly related to Characeae, as a part of national biomonitoring scheme and specific freshwater macroalgal Chrysophyta, Phaeophyta and Rhodophyta species. The latest papers were the ones published online in digital forms, and therefore much easier to access. Preliminary observation shows the tendency of recent papers to overlook some of the old information ; not only by the authors but also by the paper reviewers. We conclude that the historical information was “lost” through time due to the hardly accessible literature (local papers printed in local language) followed by a discontinuity in research. This overview provides a survey of macroalgal research through historical, hardly accessible literature, and links the results with the recent macroalgal research, therefore, we bring some recent information about occurrence of Hydrurus foetidus (Chrysophyta) ; Heribaudiela fluivatilis (Phaeophyta) ; Bangia artopurpurea, Hildenbrandia rivularis, Lemanea spp., and Thorea hispida (Rhodophyta) in Croatian freshwaters.

The history of Zagreb farmers’ markets began even before the establishment of the City itself, as early as 13th century, when the first public market was established in the area. The beginning of the today’s market system was in 1930, when the central market Dolac was opened for public. After that time and especially after the World War II, the market system enlarged and spread following the spread of the City, and nowadays includes 22 locations. Apart from food and local domestic products, the sellers sometimes offer decorative flowers, out of which some are not cultivated but collected in natural habitats. Our aim was to prepare the overview of the decorative indigenous plants sold on Zagreb farmers’ markets. We have studied all 22 locations in the period January-April 2018, by visiting the markets and surveying the sellers. We made several visits to the markets offering flowers, to include the whole spring season, while the data were collected using previously prepared, original questionnaires. Decorative indigenous plants were found on 13 locations. Total number of respondents was 50, mostly women of the average age 53. Total number of recorded plant taxa was 79, out of which 39 herbs, 15 trees, 14 shrubs, eight mosses and three vines. The respondents provided 64 different common names for a total of 45 plant taxa, mostly giving one name per species, but sometimes also several names per species or the same name for several species. Altogether 93 % of plants were sold as cuttings, while 7 % plants were provided in whole. Only six plant species were provided with underground parts, for further planting. We found two legally strictly protected taxa, Taxus baccata L. and Helleborus niger L. subsp. macranthus (Freyn) Schiffner, both listed in the Red Book as vulnerable (VU). In general, our conversations with the respondents revealed that they are rather familiar and in agreement with the legal protection of the spring flora.

The Neretva River Delta represents the largest complex of wetland habitats in the Croatian coastal zone. In addition to being a Ramsar site, the Delta is protected on the national level as one of a few preserved wetland areas in the Mediterranean region of Europe. The area is nowadays greatly transformed into agricultural land, with most water bodies well interconnected, as a result of numerous anthropogenic interventions since the 19th century onward. First records of alien aquatic plants Egeria densa and Myriophyllum heterophyllum in the Delta occured in 2013 and 2016, respectively. Prior to our survey, E. densa was recorded on five sites, while M. heterophyllum was recorded on one site in the delta. For the purpose of detailed mapping of these taxa, we carried out a survey of the Neretva River Delta in August 2018. Our search has revealed a greater abundance than previously recorded, indicating the recent spread of the two taxa. Egeria densa was rather frequent, recorded in over 12 sites, often forming dense monodominant populations, with the largest one recorded in the Norin River, a right bank tributary of the Neretva River, extending almost continuously for approximately 7 km from the Prud Spring to the settlement Romići. Myriophyllum heterophyllum was recorded in eight sites, however morphologically dubious specimens of Myriophyllum were found in additional 20 sites, possibly hybrids between alien M. heterophyllum and native M. verticillatum. Both M. heterophyllum and E. densa were recorded in bloom, with the latter developing only male flowers. Interestingly, E. densa was frequently found in springs, with water temperature below 20 °C.