The importance of forestry education and science at the University of Zagreb for the development of Croatian forestry

Šumarski fakultet Sveučilišta u Zagrebu proslavio je 2018. godine 120. obljetnicu osnutka, jer je 20. listopada 1898. godine na Sveučilištu u Zagrebu počela s radom Šumarska akademija kao prva visokoškolska šumarska institucija u Hrvatskoj i jugoistočnoj Europi. Kontinuitet visokoškolske šumarske nastave na Sveučilištu u Zagrebu zadržao se do danas, kroz razdoblja djelovanja Šumarske akademije (1898.–1919.), Gospodarsko-šumarskog fakulteta (1919.–1946.), Poljoprivredno-šumarskog fakulteta (1946.–1960.) i Šumarskog fakulteta (od 1960.). Cilj je ovoga rada objasniti kako su visokoškolska šumarska nastava i šumarska znanost na Šumarskom fakultetu Sveučilišta u Zagrebu tijekom proteklih 120 godina utjecali na stvaranje i očuvanje šumskog bogatstva Republike Hrvatske kao temeljnog, izvornog, prirodnog, biološki raznolikog i samoobnovljivog. U prilog tomu, naveden je pregled značajnijih postignuća fakulteta i njegovih istaknutih profesora.This paper explores the influence of higher forestry education and forestry science at the Faculty of Forestry of the University of Zagreb on the formation and preservation of forest wealth in the Republic of Croatia during the past 120 years as the basic, authentic, self-renewable, biologically diverse and distinctly natural element. In order to do so, we shall provide a survey of some significant achievements of the faculty and its distinguished professors by citing examples of important textbooks and scientific papers.In the year 2018, the Faculty of Forestry in Zagreb marked the 120th anniversary of its establishment. It was on October 20th, 1898, that the Academy of Forestry was founded within the University of Zagreb as the first higher forestry institution in Croatia and in the south-east of Europe.  The continuity of higher forestry education at the University of Zagreb has been retained to date through the periods of activity of the Academy of Forestry (1898 - 1919), the Faculty of Agriculture and Forestry (1919-1946), the Agricultural-Forestry Faculty (1946 - 1960) and the Faculty of Forestry (1960 - to date). Three characteristic periods can be singled out in the development of forestry education and science at the Faculty of Forestry in Zagreb in the course of 120 years: the first half of the 20th century, the second half of the 20th century and the first half of the 21st century. The first half of the 20th century witnessed a surge in the Croatian forestry, which can primarily be attributed to the development of higher forestry education and science at the Academy of Forestry and the Faculty of Agriculture and Forestry of the University of Zagreb. Among the most important contributions of university forestry education and science in Croatia are the establishment of the Zagreb School of Silviculture and the beginnings of organized and systematic scientific research in forestry. The second half of the 20th century is characterized by the blossoming of higher forestry education and science in Croatia, which had a direct impact on the condition of forests and the development of practical forestry. During this period, the Croatian forestry, science and practice became an outstanding example of mutual cooperation and powerful development, which brought about an improvement in the condition of forests in Croatia as a whole. The forestry practice firmly adhered to the principles of the Zagreb School of Silviculture, an orientation towards natural regeneration, natural stand structure, and natural, diverse and stable forests.This trend has continued in the 21st century. The new age has given rise to vast changes and challenges in higher forestry education and science. The crisis of forestry, which has gradually been evolving over the past fifteen years, has had its repercussions on the basic activity of the Faculty: higher education and science. Today, the Faculty of Forestry is confronted with two serious challenges: lesser interest of young people in studying and a reduced intensity and scope of scientific research in forest ecosystems.  There are no objective reasons for either of the above, however. Forests are the most widespread and the most important natural wealth in the continental part of the Republic of Croatia. There are currently a large number of job openings in forestry and urban forestry, as well as in nature and environment protection, and this trend will continue to rise in the future. The Croatian forest ecosystems are facing growing numbers of challenges and problems. On the other hand, there are fewer and fewer workers in forestry. In view of this, there is no reason for crisis in one of the most natural and oldest studies at the University of Zagreb. On the contrary, forestry experts have splendid prospects in today’s ecological, economic and social conditions. The task of the Faculty is to adjust itself and its basic products, experts in the management of forest ecosystems of the Republic of Croatia, to new challenges. Forestry practice and forestry science must work together, just as they have done throughout the long forestry history. Only be doing so will their development be ensured in accordance with the definition: forestry is a science, profession and art of managing and preserving forest ecosystems for the permanent benefit of man, society, environment and economy

Virgin forest and its significance for forest management in Croatia

Cilj je članka na temelju dosadašnjih znanstvenih spoznaja prikazati temeljne značajke prašume te objasniti kako se upotrebljavaju u praksi gospodarenja šumama u Hrvatskoj. Ističe se kako je prašuma nestabilna i strukturno raznolika, podložna promjenama u prostoru i vremenu. Analizirane su promjene koje doživljava u svom razvoju (razvojni stadiji i faze). Proučavanje prašume koristi u gospodarenju prirodnim šumama. Prašumu shvaćamo kao “školu prirode” koja pruža mogućnosti spoznaje životnoga puta šume od njezina nastanka do ugibanja tj. raspadanja i istodobnoga ponovnoga nastanka. To u praksi gospodarenja šumom odgovara razdoblju od nastanka šume do njezine konačne sječe i istodobne obnove. Regularne gospodarske šume se uzgajaju tako da se tijekom života održavaju u stanju koje odgovara optimalnoj fazi prašume, a pomlađuju prema načelima podfaze raspadanja. To znači kako se se sječe pomlađivanja na kraju gospodarskoga vijeka regularnih šuma obavljaju na način kojim se imitira proces prašumskoga raspadanja. Ono što je u prašumi raspadanje to je u gospodarskoj šumi pomladna sječa. Kako u prašumi, tako se i u gospodarskoj šumi istodobno s raspadanjem odnosno sječom događa pojava i rast nove generacije. Izlučivanje stabala tijekom njege šume odvija se u skladu s načelima prirodnoga odabira u prašumi. Razlika je u tome što prašuma ima apsolutno prirodne kriterije odabira, a u gospodarenju šumama odabir usklađujemo s ciljevima gospodarenja. Preborne gospodarske šume trajno se održavaju prebornim gospodarenjem u stanju koje odgovara prebornoj fazi prašume. Proizilazi to iz činjenice kako jelovo-bukove prašume dinarskoga krša trajno zadržavaju preborni izgled. Ponajprije zahvaljujući pristupu hrvatskoga šumarstva naše su šume do danas zadržale prirodni karakter, a površina im je ostala sačuvana.The purpose of this article is to show the main characteristics of virgin forest based of scientific cognitions and explain how to apply them to the practice of forest management in Croatia. It is stated that virgin forests are unstable and structurally various, liable to changes in space and time. Different changes that virgin forest goes through in its development ( stages and phases of development) are analyzed. Observation of virgin forest is used in natural forest management. Virgin forest is seen as a “school of nature” that gives opportunity to understand the life cycle of a forest from its creation to its perishing i.e. its decay and at the same time its creation again. In the practice of forest management this corresponds to the period from the creation of a forest to its final cutting and simultaneous renewal. Regular economic forests are grown in the way that throughout their lives they are kept in the condition equivalent to the optimum virgin forest phase, and are renewed following the principles of decay subphase. This means that the renewal cutting at the end of the economic lifetime of regular forests is done in the way that imitates the process of virgin forest decay. What is decay in virgin forest, that is renewal cutting in economic forest. In virgin forest, as well as in economic forest, together with the decay or cutting there is also the growth of the new generation. Separation of trees during the attendance of forests is performed in accordance with the principles of natural selection in virgin forests. The difference is that the virgin forest has completely natural selection criteria, whereas in forest management the selection is coordinated with the aims of management. Over-piny economic forests are permanently maintained through over-piny management in the condition that corresponds to the over-piny phase in virgin forests. It comes out of the fact that fir-beech virigin forest of the Dinara Mountain looks permanently over-piny. Mainly owing to the approach of Croatian forestry Croatian forests have withheld its natural characteristics, and their surfaces have been preserved

Off-Pump versus On-Pump – Intermittent Aortic Cross Clamping – Myocardial Revascularisation: Single Center Expirience

The aim of this randomised, prospective study was to evaluate hospital mortality and morbidity after myocardial revascularisation, comparing on-pump coronary artery bypass graft (CABG) myocardial revascularisation versus off-pump coronary artery bypass graft (OPCAB) myocardial revascularisation in population with multivessels coronary artery disease. Sixty patients with multivessels coronary artery diseases were scheduled to undergo coronary artery bypass grafting from January 15, 2006 to June 30, 2007 in our institution. Patients were randomized to off-pump or on-pump surgery with intermittent cross-clamping of aorta and ventricular fibrillation, using the envelope method with random numbers. In the results only difference we did find postoperatively was in Creatine Kinase-MB (CK-MB) release, the amount of bleeding and intensive care unit (ICU) stay (p<0.05). There was no diference between the two groups of patients regarding incidence of main morbidity and hospital moratlity. In summary, we didn’t find no superiority in any of the two techniques regarding on hospital mortality and morbidity

Structure, Texture and Regeneration of Dinaric Beech-fir Virgin forest of Čorkova Uvala

Istraživanje je obavljeno u dinarskoj bukovo-jelovoj prašumi Čorkova uvala u Nacionalnom parku Plitvička jezera, u razdoblju 2004–2005. godine, na sistematskom uzorku od 68 ploha postavljenih u obliku mreže, s razmacima 100 m, svaka površine 805 m2. Istraživanjem je ustanovljeno stanje strukture, teksture i pomlađivanja u prašumskoj sastojini, koja se prostire na 80,50 ha. Prašumsku sastojinu u prosjeku tvori 440 stabala po hektaru. Ukupni broj stabala opada s porastom prsnog promjera, a koeficijent (q) distribucije stabala po prsnim promjerima iznosi 1,20. Volumen sastojine iznosi 671,23 m3/ha, od čega je 52 % jele, 42 % otpada na bjelogoricu, a ostatak u iznosu od 6 % pripada volumenu smreke. Među tanjim stablima, čiji su prsni promjeri do 30 cm, kumulirano je 7,55 % ukupnoga volumena. Na stablima sred­njih prsnih promjera između 31 i 50 cm kumulirano je 19,92 % ukupnoga volumena sastojine. Ostatak volumena u iznosu od 72,53 % kumuliran je na stablima velikih prsnih promjera iznad 50 cm. Ustanovljeno je postojanje razvojnih faza, ali na malim površinama, pa se može zaključiti o prebornom obliku sastojinskog sklopa. Po hektaru površine prašumske sastojine nalazi se u prosjeku deset odumrlih (suhih i trulih) stabala, od čega je sedam stabala obične jele. Ukupna brojnost mladoga naraštaja najveća je na lokalitetima na kojima je ustanovljena prijelazna inicijalna/preborna faza razvoja. Ti su lokaliteti najrjeđe zastupljeni po njezinoj površini. Po hektaru površine prašumske sastojine u prosjeku nalazimo 6190 biljaka pomlatka. Na jelu otpada 60 %, bukvu 28 %, smreku 2 %, a na gorski javor 10 % ukupnoga broja mladoga naraštaja.Not so very long ago (the end of the 19th century) a large part of the Dinaric Mountain range in Croatia was covered by beech-fir and beech virgin forests. These forests have since been gradually converted into natural managed forests (Prpić et al. 2001). Nevertheless, several Dinaric beech-fir virgin forests have remained until the present day, including Čorkova Uvala, Devčića Tavani, Nadžak-Bilo, Plješivička Uvala, Javorov Kal and Štirovača (Prpić et al. 2001, Vukelić and Tomljanović 2001). Their total area amounts to 360 ha. The best investigated of these is Čorkova Uvala. The first scientific forest research in this forest dates back to 1957. Its structure has since been analyzed on several occasions: in a permanent sample plot of one hectare (Tikvić et al. 2006, 2004, Prpić and Seletković 1996, Prpić 1979, 1972), in 12 sample plots of 2,500 m2 each, systematically placed in the form of a network at a distance of 250 m from each other (Kramarić and Iuculano 1989) and in 153 sample plots, each sized 200 m2 and systematically set up in the central part of the old growth stand in the form of a network 50 m from one another (Mayer et al. 1980). In addition, several inventories have also been conducted as part of the management program for the management unit of Čorkova Uvala (1987), and the structure of a wider area of Čorkova Uvala – Čudinka reserve has been analyzed (Cestar et al. 1983). Most of these investigations and inventories provide an average picture of the old growth stand structure. Apart from the results of Mayer et al. (1980), there have been no in-depth analyses of its structure and regeneration. More recently, research into natural regeneration in the old growth stand of Čorkova Uvala has been intensified and initial results have been published (Roženberger et al. 2007). This work presents the results of initial comparative research into the structure, texture and regeneration in the old growth stand of Čorkova Uvala. This research was undertaken in the Dinaric beech-fir virgin forest of Čorkova Uvala in Plitvice Lakes National Park in the period 2004–2005. The research involved a systematic sample of 68 plots of 805 m2 each. The plots, set up in the form of a network, were placed 100 m from one another. The activities in each plot included measuring the terrain slope, describing the relief, assessing the canopy, identifying life stages of the virgin forest, measuring breast diameters on all trees (d1.30 > 3 cm) and classifying them by tree species. Dead trees were recorded separately. A height sample was measured in the plots and in their immediate proximity. The young growth was measured in each plot over an area of 80 m2 and classified by tree species and height. Research provided the condition of the structure, texture and regeneration in the old growth stand extending over 80.50 ha. The old growth stand is made up of 440 trees per hectare on average. Common beech and other hardwoods (OHW) account for almost half of the trees (49 %). There are 45 % of fir trees (Abies alba Mill.) and 6 % of common spruces (Picea abies Karst.). The total tree number declines with an increase in breast diameters. The coefficient (q) of tree distribution by breast diameter is 1.20. Stand volume is 671.23 m2/ha, of which fir accounts for 52 %, broadleaves account for 42 %, and the remaining 6 % relates to spruce. 7.55 % of the total volume is accumulated among thinner trees with breast diameters up to 30 cm. Trees with mean breast diameters between 31 and 50 cm contain 19.92 % of the total stand volume. The remaining volume of 72.53 % is accumulated on trees with breast diameters above 50 cm. Different developmental stages have been identified, albeit over small areas, allowing us to conclude that the stand profile has the selection form. The initial developmental stage was determined in 9 % of the cases, the optimal stage in 18 % of the cases, the terminal stage in 65 % of the cases (ageing and decomposition), and the typical selection developmental stage in 8 % of the cases. The late optimal stage and the ageing stage are the most common due to the depression-like relief of Čorkova Uvala, which protects it from severe winds and allows mature and dead trees to remain standing for long periods. The decomposition stage occurs over small areas as a consequence of fall of singe trees or small groups of trees. In the area of the old growth stand the typical initial stage is relatively modest. It occurs in gaps but also under the canopy. The typical selection stage was found in the smallest number of cases. It is the densest (548 trees/ha), with a volume of 434.70 m3/ha and the highest participation of the silver fir. There are on average ten dead (dry and rotten) trees per one hectare of the old growth stand, of which seven are trees of silver fir. The highest number of dead fir trees was recorded in the 11–20 cm diameter class. The total abundance of the young growth was found in the localities in which a transitional initial/selection developmental stage was recorded. These localities are the least represented. There are 6,190 seedlings on average per one hectare of the old growth stand. Fir accounts for 60 %, beech for 28 %, spruce for 2 % and sycamore for 10 % of the total number of the young growth. Two thirds of the seedlings are up to 50 cm tall. On average, a fir taller than 50 cm is found on every 12 m2 of the area and one taller than 100 cm on every 30 m2 of the area. Unlike beech and sycamore, no fir taller than 300 cm was found up to the taxation limit. Of the total number of the young growth up to 100 cm in height, beech accounts for 15 %, spruce for 2 % and sycamore for 9 %. Beech and sycamore prevail in height classes above 100 cm. The young growth of spruce has a secondary role and occurs sporadically, reaching a height of up to 175 cm

Variability of morphological and biological characteristics of Wild Service Tree (Sorbus torminalis (L.) Crantz) fruits and seeds from different altitudes

Aims and objectives of research: The study aimed to research the influence of altitude on dimensions, i.e. the shape of Wild Service tree fruits (Sorbus torminalis (L.) Crantz). We also wanted to test the variability of major biological characteristics of fruits and seed, the elements of seed quality and their relations. Materials and Methods: In September 2003 we gathered fruits from 24 Wild Service Trees of different ages and positions in the stand structure on three sites (Medvednica, Psunj and Južni Dilj) situated at different altitudes. The altitude of each tree was determined with the GPSmap 60CSxdevice, after which dendrometric measurements were carried out and fruits were collected.We measured fruit length (FL) and width (FW) and calculated their index (FL/FW). The mass of each fruit was weighed on the laboratory scales Sartorius and the number of fruits per kilo was calculated. The seeds were manually extracted from the fruits and the number of filled (sound) seeds per fruit was counted in line with the ISTA rules. In order to break the double seed dormancy we applied the stratification in accordance with the ISTA rules. For the statistical analysis of the data we used ANOVA, LSD test, correlation analysis and canonical discriminant multivariate analysis with the locality as a grouping variable. All statistical analyses were performed using STATISTICA 8.0 program package. Results: We obtained a positive and strong correlation between fruit length and altitude (R=0.67), i.e. between fruit shape index and altitude (R=0.71), which means that the higher the altitude of the population of the Wild Service Tree in the Republic of Croatia, the longer the fruits. At higher altitudes the Wild Service Tree seed shows a larger degree of dormancy and requires somewhat longer period of stratification. Conclusion: The observed differences between the three studied locations might be attributed to changed climatic and soil conditions

Selection of tree species for the substitution of poplar plantations along the river Drava near Osijek

U radu su prikazani rezultati istraživanja preživljenja i rasta nekih vrsta drveća kojima bi se u slučaju potrebe mogla obaviti zamjena topola u nasadima. Pokus je postavljen na području Šumarije Valpovo, u Gospodarskoj jedinici Valpovačke podravske šume, šumski predjel Topolje, odsjek 23a. Taj lokalitet predstavlja tipičan primjer slabog uspijevanja i odumiranja nasada topola, čak i nakon višekratnih popunjavanja sadnicama topole i njege. Pokus je postavljen po shemi slučajno-bloknog rasporeda, sa šest tretiranja u četiri bloka. Tretirani su sljedeći sastojinski oblici: A – hrast lužnjak, B – poljski jasen, C – bagrem, D – hrast lužnjak s običnim grabom, E – divlja trešnja s poljskim jasenom i F – divlja trešnja s običnim grabom. Pokus je postavljen 18. studenog 2009. godine.  Preživljenje biljaka je utvrđeno svake godine tijekom petogodišnjeg praćenja pokusa. Tijekom zime 2015. godine izmjerene su visine svih stabala te je određen prostorni položaj živih i odumrlih jedinki po plohicama. S obzirom na preživljenje i visine kao indikatore rasta i razvoja biljaka, najbolje su rezultate pokazali redom obični bagrem, poljski jasen i hrast lužnjak. Najlošije rezultate postigli su divlja trešnja i obični grab. S obzirom na mikroreljef, najbolje preživljenje je pokazao obični bagrem koji podjednako dobro raste u nizi i na gredi. Poljski jasen i hrast lužnjak bolje preživljenje imaju u nizi. Divlja trešnja i obični grab imaju općenito loše preživljenje, neovisno o mikroreljefu. Rezultati istraživanja pokazali su kako je nasade topola u promijenjenim stanišnim prilikama nakon višekratnih ophodnji moguće zamijeniti sa sastojinom koja svojim sastojinskim oblikom odgovara terminalnoj šumskoj zajednici istraživanoga podučja – veza i poljskog jasena s hrastom lužnjakom (Fraxino-Ulmetum laevis Slavnić 1952). Postupku treba prethoditi izrada detaljnog šumskouzgojnog plana, koji bi između ostalog definirao područja niza i greda u određenom odjelu. Nize i vlažne grede treba prepustiti poljskom jasenu koji je pokazao vrlo dobre rezultate u pokusu. Hrast lužnjak je pokazao zavidnu stabilnost i vitalitet, pa ga treba upotrebljavati u smjesi s poljskim jasenom. Obični bagrem preporuča se za najsuše lokalitete s pjeskovitim tlima koja su naglo ostala bez podzemne i poplavne vode, na kojima nema uvjeta za nastavak uzgajanja topola.The paper presents the results of research on the survival and growth of several tree species which could be used to replace poplars in plantations if necessary. The experiment was established in the area of Valpovo Forest Office, in the Management Unit of Valpovačke Podravske Šume, forest area of Topolje, sub-compartment 23a. This locality is a typical example of poor growth and dieback of poplar plantations even after multiple restocking with poplar seedlings and tending. The experiment was set up according to the randomized block design, with six treatments in four blocks. The following stand forms were treated: A - pedunculate oak, B - narrow-leaved ash, C - black locust, D - pedunculate oak with common hornbeam, E - wild cherry with narrow-leaved ash, and F - wild cherry with common hornbeam. The experiment was established on November 18, 2000. Plant survival was recorded every year over a five-year trial monitoring period. During the winter of 2015, the height of all the trees was measured and the spatial position of live and dead individuals per subplot was determined. In terms of survival and height as indicators of plant growth and development, the best results were manifested by black locust, followed by narrow-leaved ash and pedunculate oak. The poorest results were achieved by wild cherry and common hornbeam. With regard to the micro-relief, the best survival was displayed by black locust, which grows equally well both in unsoaked micro depressions (niza) and on micro elevations (greda). Narrow-leaved ash and pedunculate oak survived better in micro-depressions. In general, wild cherry and common hornbeam showed poor survival irrespectively of the micro-relief. Research results confirm the hypothesis regarding the need to replace or substitute poplar plantations under changed site conditions towards a stand whose stand form is adequately suited to the terminal forest community of the study area - spreading elm and narrow-leaved ash with pedunculate oak (Fraxino-Ulmetum laevis Slavnić 1952). The procedure should be preceded by a detailed forest management plan which would, among other things, define the areas of micro-depressions and micro-elevations in a particular compartment. Micro-depressions and wet micro-elevations should be reserved for narrow-leaved ash, which showed very good results in the trial. Pedunculate oak displayed very good stability and vitality and should therefore be used in a mixture with narrow-leaved ash. Black locust proved to be suitable in all conditions, but it is recommended to use it over the driest and sandy soils which have abruptly remained without ground and floodwater

A contribution to the knowledge of morphological-biological properties of fruits and seeds of the false indigo (Amorpha fruticosa L.)

U radu se ispituju morfološka i biološka svojstva plodova (mahuna) i sjemena grmaste čivitnjače (Amorpha fruticosa L.). U studenome 2005. godine u potpunosti su skupljeni plodovi s dvaju prosječnih grmova amorfe na svjetlu i dvaju grmova pod zastorom krošanja starih stabala. Nakon 10 dana sušenja plodova razgrnutih u tankim slojevima plodovi su izmjereni, izvagani i pobrojeni te ručno očišćeni na određenom težinskom uzorku. Apsolutna težina sjemena skupljena s grmova na svjetlu iznosila je 6, 7 g, a grmova pod zastorom 8, 8 g. Unatoč zamjetnoj razlici u veličini mahuna, a samim time i apsolutnoj težini sjemena s obzirom na to je li ono skupljeno s grmova na svjetlu ili pod zastorom krošanja, nije dokazana statistički značajna razlika u varijabilnosti mahuna (maks. promjer/maks. duljina). U skladu s Pravilima ISTA, metodom tetrazola, ispitivana je vitalnost svježega sjemena. Vitalnost sjemena u jednom i drugom slučaju bila je izuzetno visoka i iznosila je 94 % kod sjemena s grmova na svjetlu odnosno 98 % kod sjemena s grmova pod zastorom krošanja. Dio je sjemena stavljen u posudu s vodom koja je ostavljena u vanjskim uvjetima preko zime. Nakon 146 dana močenja sjemena u vodi ponovno je ispitana vitalnost. Vitalnost sjemena s grmova na svjetlu pala je za 72 %, a sjemena s grmova pod zastorom za 70 %. Ispitivano je i tonjenje mahuna amorfe u vodi sobne temperature. Nakon 10 dana potonulo je 74, 50 % mahuna s grmova na svjetlu i 86, 25 % mahuna s grmova pod zastorom krošanja. Nakon četiri tjedna zabilježen je početak klijanja mahuna u vodi, a nakon 42 dana izbrojene su proklijale sjemenke. Ukupno je proklijalo 18, 75 % sjemena s grmova na svjetlu odnosno 8, 00 % sjemena s grmova pod zastorom. Laboratorijsko ispitivanje plodova (mahuna) i sjemena obavljeno je prema Pravilima ISTA uz procjenu klijanaca (pravilni i nepravilni). U radu su posebno prikazani nepravilni klijanci (%) s kratkim opisom nepravilnosti. Najmanju laboratorijsku klijavost, prosječno 19, 13 %, imalo je sjeme amorfe močeno 146 dana u vodi, slijedi laboratorijska klijavost mahuna čuvanih na sobnoj temperaturi (48, 25 %). Najveću laboratorijsku klijavost, kao i energiju klijavosti, imalo je očišćeno sjeme amorfe (67, 50 %). Klijavost mahuna amorfe koje potječe s grmova na svjetlu bila je za 3 % veća od klijavosti mahuna skupljenih pod zastorom krošanja. Klijavost očišćenoga sjemena amorfe koje potječe s grmova na svjetlu također je bila 7 % veća od onoga skupljenoga pod zastorom krošanja

Is Mitral Valve Repair Safe Procedure in Elderly Patients?

The aim of this randomized, prospective, study was to evaluate postoperative hospital mortality and morbidity after mitral valve repair by comparing two surgical techniques for resolving mitral valve insufficiency in elderly patients. In comparison were: mitral valve repair vs. mitral valve replacement in patients older than 70 years. In period from January 1st 2006 until August 30th 2009. Eighty patients with mitral valve disease, isolated or associated with other co morbidities, were scheduled for mitral valve repair or mitral valve replacement in our institution. Patients were randomized in two groups, one scheduled for mitral valve repair and another one for mitral valve replacement using the envelope method with random numbers. Results show no difference in hospital mortality and morbidity postoperatively in both groups. In group undergoing valve replacement we had one significant complication of ventricle rupture in emphatically calcified posterior part of mitral valve annulus. In conclusion we found no distinction in postoperative hospital mortality and morbidity after using one of two surgical techniques

Influence of Light on Natural Regeneration of Pedunculate Oak (Quercus roburL.) in the Maksimir Forest Park in Zagreb

U park-šumi Maksimir, u mješovitoj sastojini hrasta lužnjaka i običnoga graba (Carpino betuli-Quercetum roboris/Anić 1959/ Rauš 1969), analiziran je utjecaj svjetla na brojnost i kvalitetu mladog hrastovog naraštaja. Pokusna ploha obuhvatila je dvije pomladne jezgre u razvojnom stadiju mladika i površinu između jezgri u fazi ponika te mlađeg i starijeg pomlatka. Analiza podataka pokazala je da se prirodno pomlađivanje na malim površinama u park-šumi Maksimir odvija uspješno. Broj biljaka po jedinici površine je zadovoljavajući i iznosi 8,3 kom/m2. Prema vrsti smjese to je mješovita sastojina hrasta lužnjaka i običnoga graba s manjim udjelom divlje trešnje (PrunusaviumL.), klena (Acer campestreL.), lipe (Tiliasp.) i mliječa (A. platanoidesL.). Prednost mješovitih sastojina ogleda se u biološkoj i ekološkoj ravnoteži, a to su glavni ciljevi gospodarenja u park-šumi Maksimir. No, kvaliteta mladog na raštaja hrasta lužnjaka je upitna. Posljedica visoke gustoće biljaka na pom-lad noj površini je visok prosječni koeficijent vitkosti mladog hrastovog naraštaja. Velik udio deformiranih debala, loše razvijenih krošnji i prevelika zastupljenost korovske vegetacije posljedica su nenjegovanja pomlatka. Utvrđene su prosječne godišnje relativne vrijednosti difuznog i izravnog svjetla u pojedinim razvojnim stadijima hrasta lužnjaka. Ovisnost broja biljaka u različitim razvojnim stadijima o svjetlosnim uvjetima pojedinog mikrostaništa potvrđena je ?2testom. Dobivena je jaka pozitivna linearna ko re lacija između prosječnog visinskog prirasta hrasta lužnjaka i vrijednosti izravnog svjetla (r = 0,5809).In a forest park Maksimir, in a mixed forest stand of Pedunculate Oak and Common Hornbeam (Carpino betuli-Quercetum roboris/Anić 1959/ Rauš 1969), influence of light conditions on number and quality of young oak growth was investigated. Experimental plot covered two regeneration gaps and the space between, including the trees in a different stage of development (seedlings, saplings and young trees). Measurements were taken in the winter 2006 and spring 2007 in a single plot within the stand. The plot was divided in 105 sub-plots of 1.5 m x 1.5 m and on each sub-plot height (cm), tree length (cm), ground level diameter (mm) and last five height increments (cm) were measured. Parallel to the measurement, evaluation of stem quality, crown form and tree health state was conducted. Spatial distribution of old grown trees at the plot area, together with crown projections, was recorded. At each sub-plot a hemispherical photograph was taken. Average annual relative values of diffuse and direct light for different development stages of Pedunculate Oak were determined. Depending on the values of diffuse and direct light, four microsites (marked: A – D) with different light conditions were defined. Results indicate that natural regeneration in naturally occurring gaps could be considered successful. Average number of trees per square meter was 8.3. Species composition of naturally occurring young trees in the gap indicates a continuation of the same forest community, namely mixed forest stand of Pedunculate Oak and Common Hornbeam with a smaller share of Wild Cherry (Prunus aviumL.), Hedge Maple (Acer campestreL.), Norway Maple (A.platanoidesL.) and Lime (Tiliasp.). Mixed forest stands are of great biological and ecological value, but also attractive to the park visitors. Maintaining them and their stability is a main management goal in this forest park. However, in naturally occurring gaps in the absence of silvicultural treatments the quality of young trees is questionable. High density of young growth at our plot resulted with high tree slenderness coefficient of 97,7. Share of deformed tree stems was significant (30.3 %), as well as share of badly developed tree crowns (44.3 %). Great abundance of weed vegetation was recorded and can be attributed to the lack of silvicultural treatments during regeneration. Chi-square test showed statistically significant dependence of number of young oak growth in different development stages with respect to the light conditions at microsite. Lower values of direct and diffuse light (microsite C) correspond with great number of oak seedlings. Surviving of oak seedling in low light conditions confirms the fact that in first few years oak is shade tolerant. However, great abundance of oak saplings at microsites A (lower values of direct and higher values of diffuse light) and D (higher values of direct and lower values of diffuse light) indicates that oak, when it arrives to the stage of saplings, favours higher light conditions. This is further corroborated at microsite B (with high values of direct and diffuse light) where young oak trees were most abundant. Quality of oak saplings and young trees was better at microsite B. Young oak trees grown in high light conditions obtained greater height increment and stem verticality. High positive correlation is obtained between Pedunculate Oak average height increment and average values of direct light (r = 0,5809)