U vegetacijskom smislu, šume hrasta crnike sastavni su dio mediteranske regije, a hrast crnika se pojavljuje kao edifikator klimatogene zajednice vazdazelenog pojasa. Tijek razvoja vegetacije u ...smislu progresije i regresije prikazan je sukcesijom crnikovih šuma. Sukcesija je prisutna ne samo na hrvatskoj obali Jadrana, nego i u cijelom Sredozemlju. U radu je prikazan pregled vegetacijskih analiza i dinamika razvoja crnikovih šuma. Istraživanjem su obuhvaćene samo MAB plohe i plohe na otoku Rabu na poluotoku Kalifrontu osnivane istraživanjima Rauša, Španjola i Barčića (plohe Šumarskog fakulteta). Uz navedeno u radu je analizirana zapaljivost i gorivost hrasta crnike s obzirom da su šumski požari najveća ugroza za šumsku vegetaciju i općenito raslinje u mediteranskoj zoni.
In the vegetative sense, holm oak forests are an integral part of the Mediterranean region, with holm oak appearing as the dominant tree species in the climatogenic community of the coniferous belt. The course of vegetation development, i.e. progression and regression, is seen in the succession of holm oak forests. Succession is present on the Croatian coast of the Adriatic Sea, and throughout the whole Mediterranean area. This paper provides an overview of the vegetation analyses and dynamics of development of holm oak forests. Research was conducted only on MAB plots and plots on Rab Island (Kalifront Peninsula, belonging to the Faculty of Forestry, University of Zagreb for the research of Rauš, Španjol and Barčić). Vegetation inventory generated a list of all plant species in the tree, shrub and undergrowth layers that were observed and recorded on the selected plots, with values for abundance (number) and cover. The combustibility and flammability of holm oak were analysed, since forest fires are the most significant threat to forest vegetation and vegetation in general in the Mediterranean zone. Multifactor analysis of variance (Sokal & Rohlf, 1995) was applied to determine the
flammability and combustibility for holm oak. Linear correlation analysis was applied to examine the relationship between individual variables. The course of vegetation development, i.e. progression and regression, shows the succession of holm oak forests (Figure 5). The figure indicates the long time period necessary for the succession of forest vegetation, particularly in the case of progressive succession and complete species conversion. This includes at least several rotations of pine stands, and is in direct correlation with the habitat conditions. The research of holm oak forests on the permanent experimental plots is particularly important. These plots are part of the international Man and Biosphere project (MAB). Vegetation research in holm oak forests can be compared between the permanent experimental plots (PEPs) in the MAB project from the islands of Rab, Brijuni, Mljet and Lokrum (PEPs no. 36, 56 and 57, 37, 77, respectively). The succession processes on the PEPs are expressed through comparisons of time series monitoring data. They indicate the formation of stand structures and the emergence of the dominant tree layer (Figure 6). Understanding the properties of forest fuels in the sense of their combustibility (ability of fuel to combust) and flammability (ability of fuel to continue to burn) is very important for understanding the start and spread of forest fires. Different methods are used to determine combustibility and flammability. The most commonly used method is that described by Valette (1990), based on the research of combustibility and flammability of leaf litter. The regression analysis established that the moisture content of fuel, mean monthly air temperature, and mean monthly precipitation levels significantly affected the combustibility of holm oak (Table 10). However, the results of the regression analysis of the flammability of holm oak on Rab Island indicated that none of these variables had a statistically significant influence on flammability (Table 12). The PEPs were established for the purpose of long-term and comparative ecosystem research, and they will continue to be used for further research to explain the succession processes in the climatogenic Eu-mediterranean community.
Travnjaci Nacionalnog parka Sjeverni Velebit većinom nisu primarni tip vegetacije,
nego su nastali kao posljedica ljudskog djelovanja krčenjem i paljenjem šuma, ispašom i
košnjom. Taj je proces ...započeo prije više tisućljeća te je kontinuirano održavao ravnotežu
između šuma i travnjaka, a rezultirao je većom bioraznolikošću no što bi bila u nedirnutom
prirodnom stanju. U drugoj polovici 20. stoljeća tradicionalne sezonske transhumantne
vertikalne migracije ljudi i stoke iz Podgorja na velebitske ljetne pašnjake prekinute su
kao posljedica snažne depopulacije Podgorja, koje je danas najslabije naseljeno područje u
Hrvatskoj. Vegetacijska istraživanja travnjaka unutar Parka tijekom 2009. i 2010. ukazala
su na veliku raznolikost travnjaka koji se međusobno razlikuju ovisno o nadmorskoj visini,
reljefu terena, značajkama tla, utjecaju vjetra i nekadašnjem načinu upotrebe. Sukcesija,
odnosno zarastanje travnjačkih površina drvenastim i grmolikim vrstama zabilježena je na
gotovo svim tipovima travnjaka, no intenzitet zarastanja i vrste kojima zarastaju ovise o
tipu travnjaka. Sukcesija je značajno sporija na travnjacima vršne zone nego na travnjacima
primorske padine zbog kraćega vegetacijskog perioda, oštrije klime, izloženosti buri te
prostranijih travnjaka koji sporije zarastaju od manjih, fragmentiranih travnjaka kakve
nalazimo na nižim nadmorskim visinama. Očuvanje travnjaka morao bi biti prioritet
upravljanja Parkom jer, osim iznimne bioraznolikosti, travnjaci nam ujedno govore i
o prošlosti čitava područja, načinu života, privređivanja, kretanja te čine neizostavan i
nemjerljivo važan dio prirodne i kulturne baštine.
Hrvatski je sabor 8. listopada 1991. donio Odluku o prekidu svih državnopravnih odnosa temeljem kojih je RH bila država članica bivše jugoslavenske federacije i proglasio njezinu punu neovisnost. Ova ...Odluka nije jedinstvena, niti jednoznačna, već je treba proučavati u kontekstu šireg, vrlo specifičnog i, u odnosu na druge primjere, sasvim posebnog ustavnopravnog procesa konstituiranja državne samostalnosti, ali i procesa njezina međunarodnog priznanja. Izuzetna specifičnost odnosa Odluke od 8. listopada 1991. i Ustavne odluke o suverenosti i samostalnosti Republike Hrvatske već gotovo 30 godina intrigiraju mnoge pravne teoretičare, ali i povjesničare, pa i političare.
Autori rada nemaju nakanu davati konačan ili imperativan sud o ovim temama, već pridonijeti boljem razumijevanju stavova o ovoj Odluci, stavljajući je u vremenski, povijesni okvir. Oni izlažu i većinu dosadašnjih pravno-doktrinarnih prijepora, gledišta međunarodne i nacionalne judikature, koji ipak idu u prilog tezi kako je 8. listopada 1991. Republika Hrvatska dobila sve oznake međunarodnopravnog subjektiviteta koji je trebalo još međunarodnopravno priznati.
On October 8, 1991, the Croatian Parliament adopted the Decision on the termination of all legal
relations on the basis of which the Republic of Croatia was a member state of the former Yugoslav
Federation and declared its full independence. This Decision should be studied in the context
of a broader, very specific and, in comparison with other examples, very special constitutional
process of establishing state independence, but also the process of its international recognition.
The specificity of the relationship between the Decision of October 8, 1991 and the Constitutional
Decision on the Sovereignty and Independence of the Republic of Croatia of June 25, 1991 has
preoccupied many legal theorists, historians and even politicians for almost 30 years. The authors of
the paper do not intend to give a definitive or compelling judgment on the issues presented. Rather,
they want to contribute to a better understanding of the views on this Decision and place it in the
historical framework. They present most of the previous legal and doctrinal views, the positions of
international and national jurisprudence, which, however, support the thesis that on October 8, 1991,
the Republic of Croatia received the entire content of subjectivity under international law, which
will be recognized at the beginning of 1992.
Most semi-natural open habitats in Europe have been traditionally maintained by anthropogenic activities, such as grazing or mowing, preventing the establishment of woody vegetation. These habitats ...harbour a remarkably rich biodiversity in terms of both plant and animal species, but are also highly threatened, mainly by agricultural intensification and land abandonment. With this Editorial we introduce a Special Issue initiated by the European Dry Grassland Group (EDGG) at the Open Landscapes Conference (Hildesheim, 2013) and the 11th European Dry Grassland Meeting (Kulikovo Pole, 2014). We aim to give a short introduction to the current conservation status, significance and research of semi-natural open habitats in Europe and present the collected articles of the Special Issue. These papers cover a wide range of different semi-natural open habitats, including wood-pastures, heathlands, steppes, semi-dry and dry grasslands across the Palearctic region and address issues related to the assessment methods, threats, management and restoration of these habitats. We conclude that, in order to ensure their conservation and to monitor the changes in open habitats, integrative approaches are needed that take into account not only vegetation records, but also multiple animal taxa, abiotic factors, management practices, ecosystem services and modelling simulations for anticipating possible future scenarios. We also recommend that decision-makers should support actions to conserve open habitats in Europe by addressing such major challenges as the encroachment of woody vegetation. We are convinced that the present Special Issue will contribute to a better understanding of ecosystem functions and support the biodiversity conservation and management of semi-natural open habitats.
Večino pol naravnih odprtih habitatov v Evropi tradicionalno vzdržuje s svojim delovanjem človek, kot na primer s pašo ali košnjo, in tako preprečuje zaraščanje z lesnato vegetacijo. Ti habitati so biodiverzitetno zelo bogati z rastlinskimi in živalskimi vrstami, vendar tudi močno ogroženi zaradi intenzifikacije kmetijstva in opuščanja obdelave. V uvodu želimo predstaviti posebno številko revije, ki jo je vzpodbudila Evropska skupina za suha travišča (EDGG) na konferenci Open Landscapes (Hildesheim, 2013) in na 11. srečanju skupine (Kulikovo Pole, 2014). Predstaviti želimo trenutni varstveni status, pomen in raziskave pol naravnih odprtih habitatov v Evropi in zbrane članke v posebni številki. Ti članki obravnavajo širok nabor različnih pol naravnih odprtih habitatov, med njimi gozdne pašnike, resave, stepe, pol suha in suha travišča palearktične regije in obravnavajo metode njihove presoje, njihovo ogroženost, gospodarjenje in obnovo. Zaključimo lahko, da moramo poleg vegetacijskih popisov upoštevati tudi številne živalske vrste, abiotske dejavnike, načine gospodarjenja, ekosistemske usluge in modeliranje predvidenih možnih prihodnjih scenarijev, če želimo zagotoviti njihovo ohranjanje in spremljanje sprememb. Predlagamo tudi, da nosilci odločanja podprejo prizadevanja za ohranjanje odprtih habitatov v Evropi z obravnavanjem tako velikih izzivov kot je zaraščanje z lesnato vegetacijo. Prepričani smo, da bo posebna številka prispevala k boljšemu razumevanju ekosistemskih funkcij in omogočila ohranjanje biodiverzitete in gospodarjenje spol naravnimi odprtimi habitati.
We investigated early spontaneous colonisation patterns during semi-dry grassland restoration at two sites in SE Austria. The sites were left to regenerate passively without addition of plant ...propagules on a former arable field and an apple orchard. The sites were prepared only by ploughing (arable field) or clear cutting (apple orchard) and subsequently mowed annually. We studied whether, four years after project initiation, target species from adjacent semi-dry grasslands had established at the restored sites. We asked: 1) Does passive restoration lead to the establishment of target species? 2) Do abiotic parameters or distance to reference sites explain early colonisation patterns? 3) Do plant traits predict the colonisation success of different species? At each site, we collected data in 4 m × 4 m plots, in which we sampled the vegetation, analysed abiotic parameters (soil potassium- and phosphorus-content, soil-pH, slope) and recorded the minimum distance to the reference site. We tested for correlations between abiotic variables, plant traits and colonisation success. Colonisation patterns were not driven by abiotic soil conditions but rather by nearest distance to the reference sites. In addition, the vegetation developed differently in the former arable field and the apple orchard. Competitive species of the Arrhenatherion and thermophilic ruderal associations dominated the early restoration stage at both sites. Passive restoration of semi-dry grasslands on former agricultural land is unlikely to succeed unless complemented by initial ploughing, nutrient stripping and addition of propagules of rare species.
Preučevali smo vzorce zgodnje naselitve vrst med obnovo polsuhih travišč na dveh lokacijah v jugovzhodni Avstriji. Travišča smo prepustili pasivni obnovi brez vnosa propagul na nekdanjo obdelano površino in sadovnjak jablan. Obe površini smo predhodno obdelali tako, da smo polje preorali, sadovnjak pa posekali in nato kosili vsako leto. Po štirih letih od začetka projekta smo spremljali, ali se na obnovljenih površinah pojavljajo tarčne vrste s sosednjih polsuhih travišč. Zanimalo nas je: 1) Ali pasivna obnova omogoča naselitev tarčnih vrst? 2) Ali lahko z abiotskimi dejavniki ali oddaljenostjo ciljnega travišča razložimo vzorce zgodnje naselitve? 3) Ali lahko z rastlinskimi znaki napovemo uspešnost naselitve različnih vrst? Na vsaki lokaciji smo postavili poskusne ploskve 4 m × 4 m, kjer smo vzorčili vegetacijo, abiotske dejavnike (vsebost kalija in fosforja v tleh, pH tal, naklon) in izmerili minimalno oddaljenost od ciljnega travišča. Testirali smo korelacijo med abiotskimi dejavniki, rastlinskimi znaki in uspešnostjo naselitve vrst. Vzorci kolonizacije so bolj odvisni od bližine ciljnega travišča kot pa od abiotskih dejavnikov tal, poleg tega se je vegetacija razvijala drugače na nekdanji njivi kot v sadovnjaku. Na obeh rastiščih so v zgodnjih fazah obnove prevladovale konkurenčno uspešnejše vrste zveze Arrhenatherion in termofilnih ruderalnih združb. Pasivna obnova polsuhih travišč na nekdanjih obdelovanih površinah bo verjetno neuspešna brez predhodnega oranja, odstranjevanja hranil in dodajanja propagul redkih vrst
Changes of species composition, plant community strategy and functional response trait turnover were studied in a succession from dry pastures to a forest community (oak-hornbeam forests). The ...following question was asked: are functional response traits and plant community strategies indicators of TAA (time since agricultural land use abandonment), thus of a specific succession stage. Indirect gradient analysis (DCA) was used in order to observe the position of the relevés along the axis and to correlate it with TAA. It was found that the position of relevés on DCA axis 1 is our proxy for TAA. Correlations (Spearman’s rho) between the occurrence of plant functional traits and TAA were performed. Low-growing herb species with scleromorphic leaves and green or red flowers are the predominant plant type on grassland areas, while plant species with digitate, hydro or mesomorphic leaves and white flowers typically prevail in forest. The proportion of chamaephytes increases immediately after land abandonment (afforestation). In a closed forest stand, there are many more herb species with vegetative propagation (bulbils). Herbal species in those stands most often reward pollinators with pollen. The ecological strategy of the entire plant community changes with spontaneous afforestation. On grassland, stress-tolerant species are dominant. After 10 years, the community is defined as CS and after 200 years as a community with a C-CS strategy.
Raziskava se ukvarja s spreminjanjem funkcionalnih rastlinskih znakov, ekoloških značilnosti vrst in ekološke strategije združbe skozi posamezne stadije zaraščanja pašnikov v odvisnosti od časa opustitve kmetijske rabe (TAA). V raziskavi smo uporabili multivariatno DCA analizo in opazovali položaj florističnih popisov v DCA prostoru in jih korelirali s TAA. Izračunali smo Spearmanov korelacijski koeficient med pojavnostjo posameznega rastlinskega funkcionalnega znaka in TAA. Nizkorastoče zeliščne vrste s sklerofilnimi listi in cvetovi rumenih in rdečih barv so prevladujoč tip rastlin na pašnikih. V gozdovih prevladujejo vrste z deljenimi, hidro ali mezomorfnimi listi in s svetlejšimi (belimi) cvetovi. Delež hamefitov se v združbi po opustitvi kmetijske rabe močno poveča (proces zaraščanja). V sklenjenem gozdnem sestoju je opazen večji delež zeliščnih vrst, ki se razmnožujejo vegetativno (zarodni brstiči ipd.). Omenjene zeliščne vrste privabljajo opraševalce največkrat s cvetnim prahom. Ekološka strategija celotne združbe se preko sekundarne sukcesije spreminja. Na pašnikih prevladujejo stres-toleratorji. Po desetih letih ima združba strategijo kompetitor/ stres tolerator, po dvesto letih pa kompetitor- kompetitor/ stres tolerator.
Nastanak Republike Hrvatske kao subjekta međunarodnog prava nije vezan uz njezino međunarodno priznanje, nego uz proglašenje neovisnosti, može se reći uz stjecanje onih prava i dužnosti na njezinu ...teritoriju koje imaju sve suverene države. Pitanje kada je Republika Hrvatska postala subjektom međunarodnoga prava se tako svodi na pitanje datuma proglašenja i stjecanja pune suverenosti, ili - što je važnije - na pitanje o efektivnosti ostvarivanja neovisne vlasti. Prema našemu mišljenju je Republika Hrvatska kao subjekt međunarodnoga prava nastala 25. lipnja 1991. donošenjem državnopravnih akata o suverenosti i samostalnosti, implicitno i neovisnosti, uz faktičnu efektivnost vlasti. Brijunskom deklaracijom, 7. srpnja 1991., je Predsjednik Republike Hrvatske preuzeo međunarodnu obvezu o odgodi primjene tih akata na rok od 3 mjeseca. Sabor, koji je isključivo nadležan o tome donijeti odluku, odgodu nije nikada usvojio. Ovdje se radi o sudaru međunarodne pravne obveze i internoga prava. Skloni smo prednost dati međunarodnom pravu i usvojiti gledište da je primjena odluka zaista bila i odgođena. Brijunskom deklaracijom nisu stavljeni izvan snage državotvorni akti doneseni 25. lipnja 1991. Učinak te deklaracije se može promatrati dvojako: nastao je povratak na ranije stanje i gubitak međunarodne pravne osobnosti Republike Hrvatske. Poništio se učinak akata o neovisnosti države, Hrvatska se vratila u status federalne jedinice SFRJ. Prema drugome gledištu su i nadalje ostvarivane puna suverenost i neovisnost, proklamirane 25. lipnja - neovisnost je u kontinuitetu, bez prekida.
V članku je predstavljena biogeografska analiza rastlinstva na prodiščih. Rezultati temeljijo predvsem na analizi rezultatov terenskega kartiranja, ki je bilo opravljeno na devetih izbranih prodiščih ...v povirnih krakih reke Save. Obravnavani so bili človekovi posegi v prodišča ter funkcijski pomen prodišč. Na podlagi rezultatov je bil izdelan grafični model sukcesije na izbranih prodiščih.
Značaj državne funkcije predsjednika republike, ako se uzme u obzir već samo i u 'najmanjem' obujmu kao ceremonijalnog predstavnika države, implicira potrebu ustavnopravnog uređenja i uredne primjene ...instituta njegova zamjenjivanja. Zamjenjivanjem predsjednika republike podrazumijeva se ustavom uređen postupak preuzimanja njegovih ovlasti i dužnosti (ili čak i samog položaja/funkcije) od strane određenog državnog dužnosnika ili kolegijalnog tijela, nastupom činjenica biološke (smrt, privremena ili trajna nesposobnost) ili pravno-političke naravi (ostavka, opoziv) na njegovoj strani. Autor u radu daje pregled ustavnopravnog uređenja ovoga instituta u državama čiji se ustavni sustavi smatraju paradigmatskim s obzirom na pojedine modele ustrojstva vlasti. Razlike se kreću u spektru od nepostojanja funkcije potpredsjednika, u državama parlamentarnog i polupredsjedničkog modela vlasti (dok postojanje u predsjedničkom modelu problem zamjenjivanja značajno olakšava), potrebe i rokova za (ne)održavanje izbora novoga predsjednika nastupom razloga za zamjenjivanje, pa do ustavom utvrđenoga niza dužnosnika pojedinih državnih tijela ili tijela u cjelini koji/a ga trebaju zamijeniti (kao i duljini toga niza), te opsegu i podjeli ovlasti koje se u slučaju zamjenjivanja prenose na iste. Usporedbom razmotrenih ustavnih rješenja izvode se zaključci o efikasnosti rješavanja ovoga ustavnopravnoga problema u pojedinom modelu vlasti u korelaciji sa značajem i širinom ustavnih ovlasti predsjednika republike u pojedinom modelu ustrojstva državne vlasti.
The book (‘Geography and plant succession. Selected examples from Slovene regions’) is dealing with ecological succession which is one of three kinds of changes in vegetation. The other two are ...regeneration (or the result of necrosis and regrowth of organisms) and fluctuation (or changes in biomass in longer and shorter time cycles–also seasonal changes). Ecological succession or ecological sequence can be understood as a temporal-spatial clarification of the evolutionary development of a community from bare soil to a stable community which is balanced with its environment. The book is divided in two parts. In the first part, succession is presented on a theoretical basis. The development of the concept of succession through history, its mechanisms and processes carried on in it are clarified. Different types of succession as well as pioneer species and climax societies as the starting and final point of the process under consideration are described. In separated chapters, invasive species and soils as well as their role in succession are discussed. In the second part, individual selected environments (gravel pits in rivers, screes, rockfall areas, fire areas and construction pits) where the two major types of succession are prevailing are presented.
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