Invasive plants of Kalnik forests

U radu se navode invazivne biljne vrste koje se javljaju u šumama Kalnika. Također se navodi i stanje njihove rasprostranjenosti u Hrvatskoj i njihov utjecaj na šume Kalnika. Ukupno je zabilježeno 14 invazivnih vrsta koje u šumama Kalnika stvaraju probleme, a to su – Acer negundo L. (negundovac), Ailanthus altissima (Mill.) Swingle (pajasen), Ambrosia artemisiifolia L. (ambrozija), Amorpha fruticosa L. (čivitnjača), Asclepias syriaca L. (cigansko perje), Conyza canadensis (L.) Cronquist (kanadska hudoljetnica), Echinocystis lobata (Michx.) Torr. et Gray (divlji krastavac), Erigeron annuus (L.) Pers. (krasolika), Impatiens glandulifera Royle (žljezdasti nedirak), Juncus tenuis Willd. (nježni sit), Phytolacca americana L. (vinobojka), Reynoutria japonica Houtt. (japanski dvornik), Robinia pseudoacacia L. (bagrem), Solidago gigantea Aiton (velika zlatnica). Najviše problema u šumama Kalnika čini bagrem, i to na svim tipovima staništa i u sastojinama svih starosnih skupina, a posebno su štete značajne u mladim sastojinama te u sastojinama u fazi obnove. Na površinama nakon čistih sječa a prije pošumljavanja, u mladim sastojinama i osunčanim čistinama starih sastojina u fazi obnove, štetu čine i gusti sklopovi krasolike, ambrozije, žljezdastoga nedirka i vinobojke. Ostale navedene vrste za sada nalazimo uz rubove šuma, cesta, vlaka, obalama vodotoka te na šumskim čistinama, gdje dolaze u manjim skupinama ili pojedinačno te za sada ne čine ozbiljne štete, ali su stalna prijetnja autohtonim vrstama, kao i bioraznovrsnosti.This paper presents an invasive plant species that occur in the forests of Kalnik. It also presents the state of the distribution and their impact on forests of Kalnik. A total of 14 invasive species in the forests of Kalnik and these are – Acer negundo L., Ailanthus altissima (Mill.) Swingle, Ambrosia artemisiifolia L., Amorpha fruticosa L., Asclepias syriaca L., Conyza canadensis (L.) Cronquist, Echinocystis lobata (Michx.) Torr. et Gray, Erigeron annuus (L.) Pers., Impatiens glandulifera Royle, Juncus tenuis Willd.), Phytolacca americana L., Reynoutria japonica Houtt., Robinia pseudoacacia L., Solidago gigantea Aiton. Alochtonous vegetation is not only inevitable, but it also appears to be a constant future challenge in the globalizing world which communicates on all levels with every means possible. Its influence should not by any means be marginalized. Its importance and influence is not completely negative and there are possible benefits and dangers which should be controlled by the preventive measures and physical regulation. The most important species in Kalnik forest vegetation is definitely acacia. It is especially important for private forest lands where acacia tree has become very popular because of its characteristics as a fast growing tree species without any special requirements with relation to growth and it gives fast results concerning timber and firewood. Private lots are usually very small and fragmented. There is a growing need for timber, therefore the trees are grown extensively, from stumps and roots. Other woody species still do not pose a serious threat in economical or biological sense. The impact of herbaceous plants differs in various areas. The most problematic issues for the forestersare thick layers of unwanted specieswhich grow in young forest stands or in forests in the phase of restorationwhere these unwanted speciesinvasively compete with autochthonous species. In biological sense, invasive species pose a constant threat not only to domestic vegetation and biodiversity, but also to human health. We should also mention apiculture, a very important and well developed activity on Kalnik. Above mentioned species are very important and interesting for apiculture as a type of rich bee pasturage. Apiculture in this area depends on acacia pasturage and it is one of very important reasons for growing acacia tree. Other tree species are also valuable for bee pasturage, especially late in autumn when there is no other bee pasturage available and they are mostly species which blossom in autumn and represent a valuable source of pollen (Japanese Knotweed, Prickly cucumber  and European goldenrod). Generally speaking, the biggest responsibility for possible consequences of invasive plant species to the vegetation of Kalnik lies on foresters who have to recognize and monitor the appearance of invasive species, especially in state forest lands where they grow and directly influence their composition and state

New localities and syntaxonomic characteristics of sea buckthorn (Hippophaë rhamnoides L., Elaeagnaceae) in Croatia

Pasji je trn glacijalni relikt, koji se je nakon povlačenja ledenoga pokrova širio prema sjeveru i višim planinskim po­lo­žajima. U Hrvatskoj je bio rasprostranjen u Međimurju i u Podravini (uz Muru i Dravu – Legrad, Bukovec, Dubra­va, Križovljan-grad). Vrlo je rijedak i u uzgoju ili subspontano proširen, te se još navodi i za područje Samobora, Skra­di­na, a u uzgoju je još zabilježen u Botaničkome vrtu Prirodoslovno-matematičkoga fakulteta Sveučilišta u Zagrebu, Nespešu, Starom Brestju (Sesvete), uz brzu cestu Sv. Helena-Bjelovar i u Park-šumi Adica u Vukovaru. Tijekom prve polovice 20. stoljeća nije bilo nikakvih novih podataka o rasprostranjenosti pasjega trna u Hrvatskoj, a u dru­goj polovici 20. stoljeća, tijekom fitocenoloških istraživanja vegetacije u priobalnome pojasu rijeke Drave u široj varaždinskoj okolici Trinajstić (1964, 1994) bilježi nekoliko grmova, bez posebne fitocenološke pripadnosti. Za Hrvatsku prve podatke o fitocenološkim značajkama vrste H. rhamnoides donosi Trinajstić (2006) i to na osnovi jedne fitocenološke snimke iz koje se može jasno razabrati da ona prema svom florističkom sastavu pripada u sintaksonomskom smislu as. Hippophao-Berberidetum Moor 1958.Najnovijim istraživanjima sukcesije vegetacije u Podravini, 26. lipnja 2015. godine utvrđeno je novo nalazište vrste H. rhamnoides sjeverno od sela Veliki i Mali Bukovec (46.3070540, 16.7275400). Napravljena je jedna fitocenološka snimka (Tab. 1). Analizom fitocenološke snimke vidljivo je da je ona bogatija vrstama (25 : 15) od fitocenološke snimke Trinajstić-a (2006) i vrlo je slična snimkama Moor-a (1958). Dosad je Trinajstić-ev (2006) nalaz pasjega trna iz 1966. godine bio posljednji zabilježeni nalaz ove vrste u Hrvatskoj. Kako su hidrološkim zahvatima uništena staništa i kako je pasji trn nestao s toga prostora novi nalaz pasjega trna i nalaz as. Hippophao-Berberdetum Moor 1958 (Berberidion vulgaris Br.-Bl. 1950) su jedini postojeći prirodni nalazi. Iz tih razloga potrebno je naglasiti da je hrvatska flora sada bogatija za jednu vrstu prirodno rasprostranjenu, a i vegetacija Hrvatske je bogatija za jednu asocijaciju kojima treba dati odgovarajuće prirodoznanstveno značenje.Common sea-buckthorn is a glacial relict, which was, after the last glaciation, spreading to the north and higher mountain positions. In Croatia, it was widespread in Međimurje and Podravina (near Mura and Drava river – Legrad, Bukovec, Dubrava, Križovljan-grad). It is very rare in cultivation or sub-spontaneous spread, some sites are referred to the ​​Samobor and Skradin area, and cultivated it can be found in the botanical garden of the Faculty of Science, University of Zagreb, Nepeš, Staro Brestje (Sesvete), by the road Sv. Helena-Bjelovar and in the Forest Park Adica in Vukovar. During the first half of the 20th century there was no new information on the distribution of sea buckthorn in Croatia, and in the second half of the 20th century, during the phytosociological survey of vegetation in the coastal zone of the river Drava in the wider Varaždin surroundings Trinajstić (1964, 1994) records several shrubs, without special phytosociological affiliation. As for Croatia, the first data on phytosociological features of the species H. rhamnoides brings Trinajstić (2006), based on one phytosociological relevé which, according to its floristic composition, in syntaxonomic terms belongs to the Ass. Hyppophao-Berberidetum Moor 1958.The latest research on vegetation succession in Podravina, 26th of June 2015, showed a new locality of H. rhamnoides, north of the villages Veliki and Mali Bukovec (WGS84 Lat: 46.307054, Long: 16.727540). One phytosociological relevé was made (Tab. 1). The analysis of the relevé shows a greater species richness (25, 15) compared to the one of Trinajstić’s (2006) and is very similar to the relevé of Moore’s (1958). So far Trinajstić-s (2006) finding of sea-buckthorn in 1966 was the last recording of this species in Croatia. As the hydrological interventions destroyed the habitats, causing the sea-buckthorn to disappear from this area, the new records of sea-buckthorn and Ass. Hyppophao-Berberdetum Moor 1958 (Berberidion vulgaris Braun-Blanquet 1950) are the only existing natural findings there. For these reasons, it should be noted that the Croatian flora is now richer for one naturally spread species, as well as the vegetation of Croatian is richer for one association which should be given an adequate importance in natural science

Phytosociological analysis of beech forests in the Žumberak and Samobor highlands (Croatia)

The Žumberak and Samobor highlands are situated in the north-western part of Croatia where the characteristics of the Dinarides, the Alps and the Pannonian Plain meet. The greater part of the area is occupied by beech forests. The aim of the study was to determine the syntaxonomic affiliation of these forest communities, and to explore their floristic and main ecological features. Numerical analyses of floristic compositions were conducted on a data-set consisting of 144 new relevés and 99 relevés from the existing literature. Relevés were made following the standard Braun-Blanquet method. For descriptions of ecological conditions Ellenberg’s indicator values were used. Six plant associations and two subassociations of beech forests were established in Luzulo-Fagion and Aremonio-Fagion alliances. The higher altitudes of the studied area are occupied by ass. Cardamini savensi-Fagetum, whereas the lower altitudes are occupied by ass. Lamio orvalae-Fagetum and Hacquetio-Fagetum. Ass. Hacquetio-Fagetum spreads on southern slopes and ridges, whereas ass. Lamio orvalae-Fagetum occurs in ditches and on northern slopes. In the warmer habitats with shallow soils on a dolomite base ass. Ostryo-Fagetum occurred. A small part of the area is characterized by silicate substrate which is occupied by ass. Luzulo-Fagetum and Gentiano asclepiadeae-Fagetum

Taksonomski status misterioznoga “Zelenoga hrasta” (Quercus× viridis Trinajstić) iz Hrvatske, temeljen na filogenetskoj analizi

The “green oak” is a well-known specific individual oak tree of unknown origin growing near Zadar in Croatia. Depending on the authors, it was described either as a hybrid taxon between Quercus cerris L. and Q. ilex L. (named Q. × viridis Trinajstić) or alternatively as a presumed hybrid between Q. cerris and Q. suber L. To finally resolve the origin of this taxon, we performed molecular analyses and investigated the phylogenetic relationships between the “green oak” and other closely related oak taxa from the surrounding area, including all putative parental species. A total of 16 individuals representing nine Quercus L. taxa were investigated based on both plastid (trnK-matK and trnH-psbA) and nuclear (5.8S + ITS2) DNA sequence variation. Placement of the green oak in the phylogenetic relationships between the studied oak taxa does not support Q. ilex as one of its parental species but rather indicates that this taxon is in fact Q. crenata Lam., reaffirming previous alternative hypothesis that the green oak is a hybrid between Q. cerris and Q. suber. We therefore confirm the presence of Q. crenata in the Croatian flora and based on historical literature survey, we explore and discuss the implication of its occurrence and possible hybridogenic origin in the Croatian territory.„Zeleni hrast“ je već dugo poznato i specifično stablo hrasta nepoznatoga podrijetla, koje raste u selu Islam Latinski blizu Zadra u Hrvatskoj, a procjenjuje se da je staro preko 200 godina (Slika 1). Svoje ime zahvaljuje činjenici što njegovo debelo kožasto zeleno lišće ostaje na stablu duboko u zimu. Zeleni hrast prema našim saznanjima po prvi puta u literaturi spominje Jedlowski (1955) te pretpostavlja kako se radi o križancu cera (Quercus cerris L.) i hrasta plutnjaka (Q. suber L.). Kasnije ga Trinajstić (1974) opisuje kao novi takson Quercus × viridis Trinajstić, hybr. nov. koji je prema njegovom mišljenju križanac cera (Q. cerris) i hrasta crnike (Q. ilex L.) (Slika 2). Nakon toga ovaj hrast bio je predmet mnogih istraživanja, kako taksonomskih, tako i ekoloških, botaničkih, anatomskih i morfoloških. Posljednji pregledni članak o zelenom hrastu (Müller i sur., 2003) zaključuje kako rezultati većine dosadašnjih istraživanja podupiru mišljenje koje je dao Jedlowski, a ne opis taksona od Trinajstića. Međutim, do danas taksonomski status zelenoga hrasta i njegovo podrijetlo ostaju neizvjesni. Stoga je u ovome radu po prvi puta provedena analiza filogenetskih odnosa zelenoga hrasta na temelju molekularnih biljega u odnosu na ostale blisko srodne vrste hrasta koje rastu u njegovoj široj regiji, uključujući sve potencijalne roditeljske vrste (Q. cerris, Q. ilex, Q. suber i Q. coccifera L.) kao i takson Q. crenata Lam. koji je poznat kao stabilni križanac vrsta Q. cerris i Q. suber u Italiji. Također su u analizu uključeni predstavnici skupine Quercus (Q. robur L., Q. petraea /Matt./ Liebl. i Q. pubescens Willd.) kao vanjske grupe. Ukupno naš set podataka uključivao je devet taksona i 16 jedinki roda Quercus L. (Tablica 1). Kako bismo konačno utvrdili taksonomski status zelenoga hrasta koristili smo kloroplastne (trnK-matK i trnH-psbA) i jezgrine (5.8S + ITS2) DNK biljege (tzv. DNK barkod regije) na temelju kojih smo rekonstruirali srodstvene odnose pomoću mreže haplotipova/ribotipova (Slika 3) te pomoću filogenetskoga stabla dobivenoga metodom maksimalne štedljivosti (Slika 4 i 5). Rezultati filogenetskih odnosa između zelenoga hrasta i ostalih zastupljenih taksona u ovome istraživanju (Slika 3, 4 i 5) ne podržavaju teoriju da je Q. ilex jedna od njegovih roditeljskih vrsta. Umjesto toga, molekularna filogenija nedvojbeno dokazuje kako je zeleni hrast zapravo takson poznat pod prihvaćenim nazivom Q. crenata, te potvrđuje alternativnu hipotezu kako se radi o križancu između vrsta Q. cerris i Q. suber. Pojedini autori u starijoj literaturi već su navodili svojtu Q. crenata na temelju morfoloških karakteristika za područje Istre i Kvarnera te Dalmacije, koristeći se uglavnom sinonimom Q. pseudosuber Santi (Strobl, 1872; Freyn, 1877; Richter, 1897; Schneider, 1906; Ascherson i Graebner, 1908-1913; Adamović, 1911; Hirc, 1916; Hayek, 1924, 1927; Lovrić, 1981). Međutim, kasnije Trinajstić (2006) ipak zaključuje kako takson Q. crenata nije zastupljen u hrvatskoj flori te je do danas ovo pitanje ostalo dvojbeno. U novije vrijeme vrsta Q. crenata zabilježena je samo u kulturi u Perivoju Vladimira Nazora u Zadru (Perinčić, 2010; Nikolić 2017). Na osnovi naših rezultata temeljnih na molekularnoj filogeniji sa sigurnošću zaključujemo da je vrsta Q. crenata prisutna u hrvatskoj flori.

Rural Garden and Parks Decorative Flora of Town Slatina (Croatia)

Za istraživano područje grada Slatine zabilježeno je 389 svojti ukrasne flore vrtova i parkova. Utvrđene svojte pripadaju odjeljku Spermatophyta, pododjeljcima Coniferophytina i Magnoliophytina te razredima Ginkgoopsida, Pinopsida, Liliopsida i Magnoliopsida. U razredu Pinopsida nalaze se 2 reda, 4 porodice, 19 rodova, 41 svojta te 35 kultivara. U razredu Liliopsida nalaze se 4 reda, 12 porodica, 29 rodova, 30 svojti te 2 kultivara, dok se u razredu Magnoliopsida nalazi 39 redova, 73 porodice, 190 rodova, 317 svojti i 50 kultivara. Udio zastupljenih svojti u razredu Magnoliopsida iznosi 81,49 %, a taj razred ima i najveću zastupljenost križanaca. Najzastupljenije su svojte iz porodice Rosaceae (43 svojte, 11,05 %) te Asteraceae (33 svojte, 8,48 %). Najveći broj kultivara (ukupno ih je utvrđeno 87) zastupljen je u porodici Cupressaceae (27 kultivara, 31,03 %), slijedi porodica Aceraceae (9 kultivara, 10,34 %). Autohtone svojte zastupljene su s 233 svojte (59,90 %), dok su alohtone svojte zastupljene sa 156 svojti (41,10 %). Zastupljenost neofita kod alohtonih svojti je 143 svojte, dok su arheofi ti zastupljeni s 13 svojti te u odnosu na autohtone svojte čine 40,10 % udjela. S obzirom na florni element autohtone fl ore najveću zastupljenost ima euroazijski florni element sa 61 svojtom, dok najmanju zastupljenost ima atlantski florni element s 3 svojte. Kultivirane i adventivne biljke autohtonoga flornog elementa čine 35 svojti. Životni oblik Phanerophyta sudjeluje s 56,56 % ukupnoga broja svojti autohtone i alohtone fl ore grada Slatine.For the studied area of Slatina, there were 389 species of ornamental plants gardens and parks. Established species belonging to Spermatophyta section, subsections and Coniferophytina Magnoliophytina and grades Ginkgoopsida, Pinopsida, Liliopsida and Magnoliopsida. In the classroom Pinopsida are 2 rows, 4 families, 19 genera, 41 species and 35 cultivars. In the class Liliopsida are 4 lines, 12 families, 29 genera, 30 species and 2 varieties, while in class Magnoliopsida are 39 orders, 73 families, 190 genera, 317 species and 50 cultivars. The share represented taxa in the class Magnoliopsida is 81.49 %, and this class has the highest representation of hybrids and crossbreeds. The most dominant species of the family Rosaceae (43 species, 11,05 %) and Asteraceae (33 species, 8,48 %). The greatest number of varieties represented in the family Cupressaceae (27 cultivars, 31,03 %), followed by families Aceraceae (9 cultivars, 10,34 %) from the determined total number of cultivars (determined total of 87 cultivars). Indigenous species are represented with 233 species, or 59.90 %, while the introduced species are represented with 156 species, or 41,10 %. Representation of neophytes in the 143 taxa of alien species, while the incidence arheofita with 13 species, and in relation to indigenous species constitute 40,10 % share. According to the indigenous flora fl oral element has the highest representation of Eurasian floral element with 61 species, while the lowest representation of the Atlantic has floral element with 3 species. Cultivated and adventive plants indigenous fl oral element consists of 35 taxa. Form Phanerophyta participates with 56.56 % of the total number of species of native and alien flora of Slatina

Photosyntesis Intensity andVegetative Growth of Pedunculate Oak (Quercus roburL.) in Common-Garden Experiment

U radu je analiziran utjecaj mikrostaništa na fiziološke značajke i vegetativni rast hrasta lužnjaka. Istraživanje je provedeno na dvije pokusne plohe koje se odlikuju različitim kemijskim značajkama, sadržajem vlage i temperaturom tla. Cilj rada bio je utvrditi utjecaj različitih kemijskih značajki tla na vegetativni rast i intenzitet fotosinteze hrasta lužnjaka, kao i odnos koncentracije klorofila i intenziteta fotosinteze. Biljke uzrasle na tlu s većom koncentracijom humusa, dušika, fosfora i kalija imaju veći intenzitet fotosinteze, veću koncentaraciju klorofila te bolji vegetativni rast. Zbog povoljnog odnosa volumetrijskog sadržaja vlage u tlu i vodnog potencijala istraživanih biljaka, njihov značajniji utjecaj na fiziološke i vegetativne značajke hrasta lužnjaka nije utvrđen. Rezultati ukazuju na visoku pozitivnu korelaciju između indeksa ukupnih klorofila u proljetnim listovima i većine fizioloških te vegetativnih značajki istraživanih biljaka.The effect of various types of environmental stress factors on forest trees is most often manifested through the reduced absorption of mineral nutriments. This results in lowered efficiency of photosynthetic pigments on the leaf’s cellular level and production of insufficient amounts of carbohydrates necessary for normal vegetative growth. Due to sudden increase in concentration of carotenoids in relation to chlorophyll, which is susceptible to a sudden destruction under the effect of stress factors, a change takes place in the relative amounts of chlorophyll and carotenoids. Because of this, the leaves in the crown of a tree temporarily lose their green color and turn yellow, which is indicative of plant’s lack of nitrogen nutrition, i.e. the nitrogen deficiency in the soil. The role of nitrogen as a plant nutriment is connected with numerous physiological processes responsible for successful growth and development of plants. For example, nitrogen is an essential element responsible for an uninterrupted continuation of photosynthetic process and vegetative plant growth, primarily because of its role in the synthesis of chlorophyll and certain proteins, such as ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), which is responsible for CO2assimilation. In the previous studies of forest trees, significant differences were determined in the intensity of photosynthesis and vegetative development regarding the diverse conditions in the habitats. These variations are usually due to the lengths of summer droughts and high temperatures, the intensity of illumination, and the differences between dry and wet years. The aim of this study was to, (1) determine the effect of various chemical characteristics of the soil on the intensity of photosynthesis and the vegetative growth of pedunculate oak, (2) establish a connection between content index of the total amount of chlorophyll in the leaf, and the intensity of photosynthesis and the vegetative growth of pedunculate oak. The study was conducted during the vegetative period in 2010, on 4-yearold plants, planted with 2 – 2,5 meters of space between plants. Based on visual differences in the leaf color, two plots have been set aside – the chlorotic and the control plots (without chlorosis). Each field contained 8 plants, i.e. 16 in total. The average height of the plants under study before the start amounted to 1.96 ± 0.44 meters, and the diameter of the trunk 2.5 centimeters, measured 30 centimeters above ground. In order to determine the differences in the soil’s chemical characteristics between the two studied plots, the samples were taken on the depth of 0–30 centimeters. The soil reaction was determined with a potentiometer in the suspension of soil and water, i.e. soil and nKCl. Humus was determined by the Thorin method, and the total nitrogen level by the Kendahl method. The content of physiologically active phosphorus and potassium was determined by the Al-method. The study determined height and diameter increment for the plants studied, and also height and diameter increment for primary branches of each plant. The number of spring and summer shoots with its attending leaves was also determined. Based on the number and surface area of leaves, as well as the projection of crown surface on the ground, index of leaf surface was calculated for each tree. The measurements of photosynthesis intensity and the index of total chlorophyll content were performed early in September. The photosynthesis intensity was measured with the help of the infrared gas analizer portable device LCpro + (ADC BioScientific). While taking photosynthesis intensity measurements, each leaf was subjected to illumination intensity of 1500 µmol m-2 s-1, CO2concentration of 380 ± 10 µmol mol-1and the air temperature of 25 ± 2 °C. The chlorophyll content index was determined by using chlorophyll content meter CCM-200. By using a portable chamber for measuring water potential, the measurement of water potential was taken in the leaves (.) of plants under study. The chemical characteristics of the soil in the test plots were shown in Table 1. There was an extremely acidic reaction in the chlorotic plot, and acidic in the control plot. The chlorotic plot was marked by an extremely low nitrogen supply, while the control plot had a medium to good nitrogen supply. The content of physiologically active phosphorus in the chlorotic plot was extremely low, while the control plot was averagely supplied with physiologically active phosphorus. Both plots under study featured accessible potassium levels on the lower margins of an average supply. The humus content in the studied plots was very low, especially in the chlorotic plot. Statistically significant difference in the measured values of water potential of the plants grown in the plots was determined only during noon measuring throughout July. In August and September, statistically significant differences in the measured values of water potential were not determined (Table 3). All the parameters of the vegetative growth of the plants under study which were grown on the control plot had statistically significant higher values compared to the plants grown on the chlorotic plot, except for the number of primary branches, which showed no statistically significant differences between the two studied plot trials (Table 4). Leaf surface index, value of which was taken in the middle and near the end of the vegetative cycle, was statistically significantly higher in the control plot than in the chlorotic plot (Figure 2). There was statistically significant difference in the intensity of photosynthesis measured on spring leaves of studied plants between the control and the chlorotic plot. The intensity of photosynthesis on the control plot was 28.4 µmol CO2m-2 s-1, while its value on the chlorotic plot was 19.3 µmol CO2m-2 s-1. Content index values of total chlorophyll in the leaves of the studied plants were statistically significantly different regarding the plots under study, no matter whether the measuring of chlorophyll content was conducted on spring or summer leaves (Figure 4). Regression analysis determined a high positive correlation between the content index of total chlorophyll measured on spring leaves of studied plants with the intensity of photosynthesis, leaf surface index, tree’s girth increment, and also length and girth increment in the primary branches (Table 5). The correlation between content index of total chlorophyll and tree’s height increment was very weak. The results of the study indicate that the soil’s chemical characteristics have an effect on the photosynthetic activity and the concentration of chlorophyll in the leaves of pedunculate oak. The higher values of the total chlorophyll’s content index and the intensity of photosynthesis were recorded for plants grown on the soil with a higher concentration of humus, nitrogen, phosphorus and potassium. Positive correlations between the content indexes of total chlorophyll in leaves and the intensity of photosynthesis, as well as most of the parameters of vegetative growth, indicate the possibility of successful application of chlorophyll measuring methods when determining vitality of particular trees and forest stands of pedunculate oak

Population differentiation in the wild cherry (Prunus avium L.) in Bosnia and Herzegovina

Background and Purpose: The wild cherry (Prunus avium) has great and multiple importance. The fruits it produces are used for several purposes (as food for people, birds and other animals, as well as in phytotherapy). As many birds and mammals feed on the fruit of the wild cherry, it has the ability of dispersion over large areas in a very short time. It is present in from river deposits up to 1900 m/alt, while it is quite rare in the Submediterranean. Wild cherry grows as a solitary tree or in small groups, usually at the edge of the forest or within the forest in areas with more sunlight. The significance of the wild cherry is reflected in the high conomic value of its wood, which makes itmuch demanded and popular, and thus endangered. Materials and Methods: The plant material was collected from 22 natural populations in Bosnia and Herzegovina. The fruit and leaves were collected from marginal or solitary trees, usually from the south-facing,outer sun-exposed parts of the tree crown. We measured the following fruit characteristics: fruit length (FL), fruit width (FW), fruit thickness (FT), seed length (SL), seed width (SW), seed thickness (ST), length of the stalk (LOS) and width of the stalk (WOS), and leaf characteristics: length of the petiole (LP), length of the leaf blade (LB), distance from the blade base to the blade’s widest part (BBW), width of the leaf blade (WB), insertion angle of the leaf venation (AV), number of leaf teeth on a 2-cm length (NT), blade width at 1 cmfrom the blade apex (WBA) and blade width at 1 cm from the blade’s base (WBB). All statistical analyses of the data were made using the SPSS 15.0 package for Windows. Results: The results obtained show the presence of a high level of intrapopulational, as well as interpopulational, morphological variability in the natural populations of the wild cherry which have been investigated. Analyses of population differentiation have not confirmed our expectations. Our results only indicate differentiation in fruit size characteristics, but the indicators are very weak. The resulting high values of the regression coefficient in this research can serve to estimate the values of some features and characteristics without their measurement. Conclusions: The analyses of 16 morphological characteristics in 22 natural populations of the wild cherry in Bosnia and Herzegovina showed statistically significant differences between investigated populations. Differentiation in natural populations of the wild cherry was very low and identified only in fruit dimension characteristics

Vegetation Succession After the Cutting of Conifer Cultures on the Kalnik Mountain (Croatia)

Šumskim se kulturama u Hrvatskoj, a i na Kalniku gospodari oko dva stoljeća. Obnova i supstitucija tih staništa nakon propadanja ili čistih sječa odvijala se dosad gotovo stihijski, a načini obnove nisu dovoljno znanstveno istraživani ni valorizirani. Podizalo se ovisno o stanišnim uvjetima hrastovima (kitnjak i lužnjak), bukvom i crnom johom, a pojedinačno su unašane voćkarice, javori (gorski i mlječ) i europski ariš. Cilj je ovoga rada bio istražiti sukcesiju vegetacije nakon sječe kultura četinjača i njihove obnove autohtonim listačama. U tom smislu istraživana je vegetacija takvih obnovljenih staništa i uspoređivana je sa stanjem vegetacije prirodno podignutih mladih sastojina sličnih ekoloških uvjeta i starosti. Osim toga istraživan je i florni sastav srednjedobnih i starijih sastojina na okolnom području radi usporedbe s flornim sastavom obnovljenih površina nakon sječe kultura četinjača. Istraživanja su provedena na području cijelog Kalnika i to državnih šuma kojima gospodari UŠP Koprivnica (Šumarije Koprivnica, Križevci, Ludbreg, Sokolovac i Varaždin), te šumama šumoposjednika. Rezultati istraživanja ukazuju na smjer sukcesije mladih sastojina (umjetno i prirodno podignutih) na prepoznatim sušim ili vlažnijim staništima prema prirodnoj vegetaciji utvrđenoj istraživanjem okolnih prirodnih starijih sastojina. Dinamika i tijek sukcesije ovise o stanišnim uvjetima kao i načinu podizanja mladih sastojina.Forest cultures in Croatia, and also on the Kalnik Mountain, have been managed for about two centuries. Two habitat types were determined for the surfaces reforested after the cutting of the cultures and the naturally rejuvenated young stands, i.e. more humid and more arid habitat type. During the analysis of the vegetation composition, the presence of a larger number of species, many of which non-forest, was determined on artifi cially reforested surfaces, in comparison with the naturally rejuvenated ones. We determined a significant similarity in vegetation composition between more humid types of both ways of stand rising, as well as their similarity with humid types of old stands. The same similarity was also determined for more arid habitat types, therefore artificially reforested more arid habitats and naturally rejuvenated ones in comparison with the vegetation composition of middle-aged and old stands. Th e analysis of the soil samples taken from young stands of both types of rising showed higher stability and resistance to degradation processes in more humid habitat types, because humidity is a good habitat preservative. Such habitats are formed on more impermeable soil less susceptible to drainage, thereby to nutrient loss, but also to acidification. The final confirmed thesis is that the vegetation of the artificially reforested habitats after the cutting of the cultures will, within a certain period of time and certainly depending on the habitat conditions, approach and equalize the one from the natural rejuvenation. It will, therefore, progress in direction of the natural stands, considerably faster on more humid than on more arid habitats. Th e problem of the young artifi cially raised stands, where the right species has not been chosen, still remains