Flora of Hrastovička Gora (Petrinja city area)

Hrastovička gora is the northernmost part of the hilly area of Zrinska Gora in Banovina (Sisak-Moslavina County). No systematic research on flora of this region was ever done. An inventory of the flora was conducted in 2020. In all, 433 plant taxa were found, belonging to 90 plant families. The most frequent families are Fabaceae (36 taxa), Asteraceae (35 taxa), Lamiaceae (31 taxa) and Poaceae (31 taxa). Analyses of chorological types, life forms and origin were made. The most common chorological type is Eurasian (40.1%), followed by European (14.8%) and Mediterranean (11.6%). Most taxa (80.1%) are of indigenous origin, but as many as 19 invasive plant species were recorded. Almost two-thirds of all taxa are either hemicryptophytes (44.2%) or geophytes (20.4%). Only one endemic species was found, namely Helleborus atrorubens Waldst. et Kit. A large number of endangered and strictly protected plant taxa were also recorded with 17 taxa being threatened and 14 taxa being strictly protected. Forests and thermophilous grasslands have been shown to be important habitats for endangered and strictly protected species and it is therefore crucial to keep a management regime that will conserve their favourable status, while preserving stable ecological conditions

Prilog poznavanju rasprostranjenosti vrste Damasonium polyspermum Coss. (Alismataceae) u Hrvatskoj

Damasonium polyspermum Coss. occurs only in the Mediterranean, and is relatively rare across the whole distributional range. It grows in shallow standing water bodies with significant fluctuations of the water level, and it is considered characteristic for Mediterranean temporary ponds, which are rare and endangered habitats. According to IUCN, D. polyspermum is globally vulnerable (VU). In Croatia this species is denoted as data deficient (DD), however, more recently it was proposed to category endangered (EN), to critically endangered (CR). Until this record, there were only two known localities of D. polyspermum in Croatia, both in Northern Dalmatia. In June 2014 we have discovered a new locality of D. polyspermum in the area of Vrana Lake in Northern Dalmatia. Due to the specific ecological requirements which account for the small number of findings, new localities of D. polyspermum represent a significant contribution to the knowledge on its distribution.Vrsta Damasonium polyspermum Coss. rasprostranjena je isključivo u Mediteranu, s relativno rijetkom pojavnošću u čitavom arealu. Uspijeva u plitkim, slatkovodnim stajaćicama kod kojih dolazi do značajne fluktuacije razine vode, te se smatra karakterističnom vrstom za mediteranske povremene lokve, rijetka i ugrožena staništa. Ova vrsta je globalno procijenjena kao osjetljiva (VU), dok za nacionalnu procjenu prilikom izrade aktualne Crvene knjige nije bilo dovoljno podataka, pa je vrsta označena kao nedovoljno poznata (DD). Ipak, novija razmatranja ukazuju na to da je vrsta ugrožena (EN) do kritično ugrožena (CR). U Hrvatskoj je do sada zabilježena na svega dva lokaliteta u sjevernoj Dalmaciji. U lipnju 2014. pronašli smo novo nalazište ove vrste, na području Vranskog jezera u sjevernoj Dalmaciji. Zbog vrlo specifičnih ekoloških zahtjeva, koji su odgovorni za mali broj nalaza ove vrste, novi nalazi predstavljaju značajan doprinos poznavanju rasprostranjenosti ove vrste

BEAUTY OF BIOLOGY (cover image)

BEAUTY OF BIOLOGY As announced with first such cover in our issue 1 in 2017 (https://doi.org/10.18054/pb.v119i1.bb1), occasionally cover image will not be related to one of the papers in the issue itself. About the image: Photograph show Alpine longhorn beetle – Rosalia alpina (Linnaeus, 1758) taking a rest on the leaf of the black locust – Robinia pseudoacacia L. and could be called “Beauty and the Beast”. Alpine longhorn beetle is listed on the Annex II of the Habitat Directive (most important nature protection Act in the European Union) and on the Bern Convention, as protected and important as an indicator of favourable status of the woodland and forest habitats. Being a saproxylic species (like e.g. stag beetle), its presence in some area is dependent on the existence of dead wood, which implies type of the forest managements that will promote such conditions for the benefit of numerous organisms that rely on the dead and decaying wood. Black locust is as well, present in the various lists, but those of the invasive species! Originated from the North America, it was deliberately introduced out of its native range for the ornamental and other purposes (e.g. soil stabilisation, bee forage), but nowadays it is invading open habitats, and somewhere poses a serious threat to the native biodiversity. The photograph was taken by Sven D. Jelaska, on July 27th, 2019. around 5 P.M. in Medvednica Nature Park, which is part of the NATURA2000 network in Croatia

120th Volume of Periodicum Biologorum and 21st FIFA World Cup – what do they have in common?

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Distribution and morphological variations of invasive macrophytes Elodea nuttallii (Planch.) H. St. John and Elodea canadensis Michx in Croatia

The invasive species Elodea nuttallii was recorded for the first time in the Croatian flora in 2006, in the drainage channels of Kopački rit (Baranja). After its establishment, E. nuttallii begins to spread to the eastern and northern part of the drainage channel network from 2006–2009. High water levels are responsible for the linear spreading direction of E. nuttallii, E. nuttallii and E. canadensis show a wide range of morphological variation, which is characteristic of successful invaders. To show morphological variations of two Elodea species, the most impor tant characters indicated in the literature were measured on 24 fresh collected samples from the seven sites in Croatia. In spite of some overlap in leaf length and width between the two Elodea species, the differences of all morphological traits except internode length are statistically significant. In E. nuttallii leaf width, length and internode length show a higher morphological variability as a result of the higher adaptive strategy to environmental parameters. The most reliable morphological characters distinguishing E. nuttallii and E. canadensis are leaf width 0.5 mm below the tip and the angle at the apex. E. nuttallii can be expected to spread to other areas of Croatia

Australian acacias across eastern Adriatic – abundant but not aggressive

Background and Purpose: Biological invasions are considered among the main factors of global changes and the identification of future invaders may help in taking effective steps to prevent their dispersal and/or establishment. For some Australian Acacia species, especially Acacia dealbata Link, an invasive status has been already described in some European countries. The aim of this work was surveying the actual spatial pattern of Australian acacias across the eastern Adriatic, and, by applying GIS techniques, to learn more about their ecology and distribution. Materials and Methods: We carried on two field surveys during the flowering season of the year 2014, and recorded the locations of Acacia species, their flowering state, floral characteristics, and the insects present on the inflorescences. We georeferenced any plant detected, and collected soils samples under the plant crowns and in close natural or semi-natural areas. Results and Conclusions: Very few species were recorded and mostly in private gardens, A. dealbata being the preferred ornamental. Records referring to plants grown in abandoned or unattended gardens demonstrate the potential of this species to expand if not properly controlled. In addition, we detected no plants outside gardens in natural habitats. Results on soil characteristics, with higher pH values than those usually found under trees of this genus elsewhere, may partly explain our findings. The surveys took place during a spring following an unusually warm winter: this may have influenced both phenology and pollinator activity, finally reducing observations of the latter. Descriptive statistics and MaxEnt analysis have shown the importance of the warmer areas in determining the presence of Acacia species. At present, acacias are not to be considered aggressive invaders along the eastern Adriatic according to our observations; they can be classified as alien, with a local trend toward becoming casual

Possible Implications of Two Management Types in Olive Groves on Plant Diversity

To evaluate the impact of two predominant management types (mowing vs. tilling) in olive groves on plant diversity, we have surveyed olive groves at ten localities in the surroundings of Šibenik (Dalmatia, Croatia). Among the surveyed groves, 12 were managed by tilling and 11 were managed by mowing. Altogether 323 taxa from 207 genera and 58 families were recorded. The families with the highest numbers of taxa were Fabaceae, Poaceae, Cichoriaceae and Asteraceae. Mowed olive groves were significantly richer in flora (280 taxa) in relation to the tilled ones (181 taxa), with 138 taxa in common to the both management types. An analysis of the life forms showed the domination of therophytes (54.18%) and the phytogeographycal analysis showed that the most frequent floral element was Mediterranean (46.13%). Mowed olive groves almost exclusively contained endemic and endangered species while the invasive alien plant taxa were recorded mostly in the tilled olive groves. Mowing seems as much better management practice from the standpoint of the nature conservation. Based on its floristic composition and richness, tillage seems to completely remove the nursing effect that olive groves can provide for the dry grasslands listed in the Annex I of the Habitat Directive, which are otherwise, in open spaces without grazing exposed to disappearing through the process of secondary succession

Grime’s CSR strategies of the invasive plants in Croatia

Background and Purpose: Biological invasions are causing serious problems in the environment, often resulting in significant modifications of the landscape structure and ecosystem functioning. J.P. Grime’s theory on CSR strategies of plants indicate whether plant species is a good competitor, adapted to disturbance or to limited resources. The goal of this study was to find which CSR strategy (if any) prevails among invasive plants in Croatia. Materials and Methods: Data on CSR strategies were not available, or not consistent, for all invasive plants in Croatia, hence we have allocated CSR strategies to 15 invasive taxa, using the methodology based on several plant traits, which resulted in assignment of CSR type to 57 invasive plants. Distributional records of those 57 taxa in Croatia from the Flora Croatica Database were used to analyse the occurrence of invasive plants among three biogeographical regions (Alpine, Continental and Mediterranean). Results and Conclusions: In total, 10 CSR types were found among the invasive plants of Croatia, mostly CR-strategists, followed by C-strategists and R-strategists. The largest proportion of R-strategists was found in the Mediterranean region, while the largest proportion of C-strategists was found in the Alpine region. Out of the three main strategies, competitive ability and ruderality were found to be frequently present within the Croatian invasive flora, while stress tolerance was almost absent

Plant diversity and chemical soil composition of rocky pastures in relation to the sheep grazing intensity on the northern Adriatic islands (Croatia)

Optimal grazing pressure on rocky pastures is beneficial to the development of plant species and maintenance of plant diversity. Both abandonment of grazing and overgrazing gradually reduce plant diversity. This paper correlated abundance patterns of the flora on rocky pastures with the values of the chemical composition of the soil resulting from the degree of sheep grazing intensity. The study was carried out in the period from 2008 to 2010 on the islands of Pag, Krk and Cres. At 30 sites, 310 taxa of vascular plants were found. The highest plant diversity and 220 plant taxa were found on moderately grazed pastures. Abandoned pastures with a total of 93 plant taxa observed show the dominance of phanerophytes (35.5%) and the highest proportion of the Mediterranean floral element when compared to pastures of moderate and heavy grazing intensity. The highest concentration of total nitrogen in the soil (0.71%) was recorded on plots of heavy grazing intensity. The results of the study indicate that moderate grazing intensity, from 1 to 1.5 sheep ha–1, can be recommended on the northern Adriatic islands. This should contribute not only to the preservation of plant diversity, but also to the improvement of ecological sheep farming