This paper presents the results of the preliminary testing of the selected trace elements in the soils of several parks in the city of Zagreb, Republic of Croatia. In each park, the samples were ...taken from several points—at various distances from the roads. The samples were taken at two different depths: 0–5 and 30–45 cm. Composite samples were done for each sampling point. Microwave-assisted wet digestion of the soil samples was performed and the determination by ICP-AES technique was done. Results obtained for Al, As, Ba, Mn, Ti, V, and K are in a good agreement with the results published in the scientific literature so far. The mass fraction values of Cd, Cr, Cu, Ni, Pb, and Zn are somewhat higher than the maximum values given in the Croatian Directive on agricultural land protection against pollution. Be, Mo, Sb, Se, and Tl in the samples were present in the concentrations that are lower than their method detection limit values.
U radu su prikazani rezultati ispitivanja laboratorijske klijavosti i morfoloških značajki klijanaca europskoga pitomoga kestena (
Castanea
sativa
Mill.). Uzorci za istraživanja sakupljeni su u ...submediteranskom području Hrvatske, a radni uzorak za ispitivanje klijavosti iznosio je 8×25 sjemenki. Sjeme je do ispitivanja klijavosti čuvano tri mjeseca u hladnjaku na temperaturi od 3 °C. Postotak laboratorijske klijavosti utvrđen je prema postotku pravilnih klijanaca koji su normalno proklijali nakon 27 dana ispitivanja. Ispitivanje je provedeno u laboratoriju prema uvjetima koje propisuje ISTA (
International Seed Testing Association
). Izrađen je katalog sa slikama i opisom nepravilnih klijanaca. Na osnovi definiranih kodova nepravilnih klijanaca moguće je preventivno djelovati kako bi se reducirale nepoželjne jedinke. Rezultati ovog istraživanja od velike su koristi za razumijevanje složenoga procesa klijanja sjemena, kako u laboratoriju, tako i šumskim rasadnicima.
The paper presents the results of laboratory germination testing and morphological characteristics of sweet chestnut (
Castanea
sativa
Mill.) seedlings. The research samples were collected in the sub-Mediterranean region of Croatia, and the working sample for germination testing was 8×25 seeds. Prior to germination testing, the seeds were stored in a refrigerator for three months at 3°C. The percentage of laboratory germination was established according to the percentage of regular seedlings which germinated normally after 27 days of testing. The testing was carried out in a laboratory under the conditions prescribed by ISTA (International Seed Testing Association). A digital photo camera was used to take photos of all abnormal seedlings, which were then catalogued with their pictures and descriptions. The results of this research are very useful for nursery practice and can be applied in producing plants from seeds, rootstocks for grafting, and further raising of seedlings to be grown in plantations.
Matični supstrat, uz klimu, reljef, organizme i vrijeme, predstavlja jedan od pet glavnih pedogenetskih čimbenika. S pedogeneskog stajališta najvažnija su svojstva matičnog supstrata: mineralni i ...kemijski sastav, način i intenzitet trošenja te sadržaj biogenih elemenata. Cilj ovog rada je utvrditi utjecaj različitih matičnih supstrata na fizičke i mineralne značajke tla. Na području PP Medvednice na šest različitih litoloških cjelina otvoreno je 80 pedoloških profila: metamorfne stijene – dominantno škriljevci, metamorfne stijene – dominantno filiti, magmatske stijene, pješčenjaci, lapori i lako trošivi vapnenci. Uzorci tla uzeti su po horizontima, a analizirani su oni iz humusnoakumulatinog (A-horizont) i B-horizonta. Određeni su sljedeći parametri: debljina horizonata, dubina profila, udjel skeleta, garnulometrijski sastav tla, postojanost strukturnih mikroagregata i mineralni sastav tla (XRD) metodom rendgenske difrakcije. Rezultati istraživanja pokazuju da postoje statistički značajne razlike između različitih litoloških cjelina za sve promatrane varijable osim debljine horizonata. Najveće dubine tla su povrh laporovitih stijena, a najmanje na dolomitiziranim vapnencima, što je ponajprije uvjetovano načinom trošenja matičnog supstrata. Na svim istraživanim litološkim cjelinama, tla na području PP Medvednice vrlo su postojanih mikroagregata. U odnosu na B-horizont u humusnoakumulativnom horizontu utvrđena je veća postojanost strukturnih mikroagregata. Tla povrh lakotrošivih vapnenaca imaju statistički veći udjel gline i manji udjel krupnog i sitnog pijeska od tla ostalih litoloških cjelina. Za sve litološke cjeline teksturna oznaka najčešće je u rasponu od praškaste do glinaste ilovače, dok je na litološkoj cjelini povrh vapnenaca udjel gline statistički značajno veći, pa je teksturna oznaka u rasponu od praškaste glinuše do glinuše. Litološke cjeline povrh magmatskih i metamorfnih stijena imaju statistički značajno manji udjel minerala kvarca i veći udjel minerala klorita i feldspata u odnosu na sedimentne stijene.
The highly complex lithological structure as well as topographic characteristics of the Medvednica area are responsible for its profound vegetational, micro-climatic and pedophysiographic diversity. In view of the quality of the original soil-forming material, the first place is taken by rocks and their detritus which directly govern soil physical composition. The best indicators of soil physical composition are its depth, colour, skeletal nature, particle size distribution, soil density, density of soil solid phase, total porosity, water capacity, air capacity, structure and hydraulic properties. On Medvednica, these vary greatly and play the main role in defining soil quality. The success of ecosystem management depends on the knowledge of the above factors. The goal of this research is to determine how the lithological base, or parent material, primarily affects physical (horizon thickness, profile depth, skelet proportion, soil texture, soil structure) and mineral soil properties.
A total of 80 pedological profiles were opened in the Medvednica Nature Park area and evenly distributed so as to comprise all the representative lithological units. Samples of physically altered soils were taken from genetic horizons, as well as a fragment of rock, i.e. parent material, for the purpose of determining the lithological rock affiliation. Soil samples has been analayzed in the humus-accumulative (A horizon) and first under mineral horizon (mostly B horizon). The differences between the topsoil humus-accumulative and B horizon were statistically analyzed per lithological units. The samples were prepared (ISO 11464 2006) and analyzed in the laboratories of the Faculty of Forestry of the University of Zagreb and at the Croatian
Geological Institute in Zagreb. According to FAO (2006), the following was determined in situ: the proportion of skelet per genetic horizon, horizon thicknesses and total profile depth. Laboratory analyses of the samples taken from genetic horizons included the particle size distribution according to ISO 11277:2009, stability of structural microaggregates according to Pernar et al. (2013) and mineral soil composition (XRD) using the X-ray diffraction method on X-ray diffractrometer X’Pert PRO MPD.
For the needs of statistical analysis, parent material was divided into six characteristic units, leaning in part on the classification of Halamić et al. (2001) used during geochemical research of stream sediments on Medvednica. The lithological unit LIT1 is represented by metamorphic rocks, predominantly greenschists, muscovite chlorite and quartz-muscovite schists. The lithological unit LIT2 is represented by metamorphic rocks, predominantly phyllites. The lithological unit LIT3 consists of igneous rocks, predominantly diabases and spilites. The lithological unit LIT4 are Mesozoic clastic rocks of Lower Cretaceous age, and comprise sandstones, siltites and shales. The lithological unit LIT5 consists of Mesozoic and Tertiary clastic rocks dominantly represented by marls. LIT6 is made up of Tertiary carbonate rocks represented by lithotamnic limestones together with clay limestones (Figure 1).
Statistical analysis was performed with Statistica 7 software. Descriptive statistics was made for all the analyzed variables, including the number of samples, arithmetic means and standard deviation. Differences between the analyzed variables by lithological units were tested with a one-way analysis of variance (ANOVA), on condition that the assumption of homogeneity of variance was satisfied. For those variables in which the test of homogeneity of variance was not satisfied, the Kruskal-Wallis non-parametric test was used. Type I error (a) of 5 % was considered statistically significant.
The following soil types were identified in the opened pedological profiles: dystric cambisol, eutric cambisol, calcaric cambisol, stagnosol, regosol and luvisol (the percentage ratio by representation is 62 % – 19 % – 10 % – 4 % – 3 % – 2 %).
Based on the comparison of soils formed in six different lithological units, it can be concluded that physical and mineral soil properties depending on type of litological units. Silty to clay loam is the most represented textural class in Medvednica Nature Park. It was found on metamorphic rocks above greenschist and phyllite, igneous rocks, sandstones and marls, whereas on easily weathered limestones the textural class ranges from silty clay to clay. The analysis of particle size distribution (content of individual fractions) showed that the profiles developed on silicate lithological parent material have on average higher sand content compared to the profiles developed on carbonate rocks, which is conditioned by the manner of parent rock weathering. Higher clay content above easily weathered limestones eventually led to variability of the textural class in relation to other lithological units. In all the investigated lithological units in terms of structural microaggregate stability, the soils in Medvednica Nature Park manifest highly stable microaggregates. In relation to the B-horizon, the humus-accumulative horizon revealed higher stability of structural microaggregates, which can be attributed to higher content of organic matter in the topsoil horizon. The soils above igneous and metamorphic rocks have significantly lower content of the mineral quartz and higher content of the minerals chlorite and feldspar in relation to the soil above sedimentary rocks. There was no difference in muscovite/illite contents in lithological substrates. Soil was the deepest above marl rocks and the shallowest above dolomitised limestones, which is primarily conditioned by the manner of parent material weathering.
Our research highlights all the complexity and heterogeneity of the geological-lithological structure of Medvednica. In combination with other pedogenetic factors, it manifests even higher soil heterogeneity, which eventually causes problems in the processing and interpretation of the results.
This research provides reference data on physical and mineral properties of soils in Medvednica Nature Park in the most represented lithological units. However, these data should be taken with caution and should be compared with the results of other similar studies, since the same lithological parent material may give rise to the formation of soils of different taxonomic affiliation, depending on the changes in the constellation of other pedogenetic factors (climate, vegetation, relief).
The quantity and quality of seedlings in the nursery has an impact on the success of re-establishment and later growth. High germination rates enable a sufficient number of seedlings, and their ...quality is assessed using a number of parameters, including seedling height and root collar diameter. These parameters are influenced in some species by seed size, but the correlation between them is species-specific. The model species in this research was sweet chestnut (Castaneasativa Mill.), and seeds from 12 populations from two distinct biogeographical regions of Croatia were collected. We examined the influence of seed size on four parameters: germination rate, seedling height, root collar diameter and sturdiness quotient. Seed size has been shown to have a positive influence on both seedling height and root collar diameter, whereas no such correlation was noted for germination rate and sturdiness quotient. Significant differences in nut size and seedling growth parameters were found between the Mediterranean and continental populations, with higher values observed in the coastal Mediterranean populations. We concluded that seed origin and seed size have a significant impact on seedling growth and are important factors to consider when choosing seed material. Further nursery operations should consider seed origin and local environmental conditions when choosing seedlings for reforestation efforts and general forest operations.
Kalkokambisol (smeđe tlo na vapnencima i dolomitima) jedno je od najzastupljenijih tipova tala u Hrvatskoj. Kako i sam naziv sugerira razvijeno je na vapnencima i dolomitima, koji uključuju niz ...prijelaznih formi stijena u pogledu načina i intenziteta fizičkog i kemijskog trošenja. Na području Nacionalnog parka Plitvička jezera otvoreno je 30 pedoloških profila od kojih je 18 na vapnencima i 12 na dolomitima. Na terenu su bili određeni ektomorfološka i endomorfološka svojstva tla. Na prikupljenim uzorcima tla iz humusno-akumulativnog (A) i kambičnog (B) horizonta određeni su sljedeći parametri: granulometrijski sastav tla, reakcija tla odnosno pH-vrijednost u vodi i vodenoj otopini CaCl2, udjel karbonata te udjel organskog i ukupnog dušika. Najveće razlike u ektomorfološkim parametrima između tala povrh vapnenaca i dolomita utvrđene su u stjenovitosti i kamenitosti – na vapnencima se ona kreće u rasponu od vrlo niske do vrlo visoke, dok je na dolomitima nema. Na profilima kalkokambisola povrh dolomita utvrđen je veći udjel frakcija pijeska i manji udjel gline od kalkokambisola povrh vapnenaca. Dominantna teksturna oznaka u B-horizontu koji je ujedno i dijagnostički horizont kalkokambisola povrh vapnenaca je praškasta glina dok je kod kalkokambisola povrh dolomita praškasto glinasta ilovača. Prosječne pH-vrijednosti i udjeli CaCO3 u kalkokambisolima povrh vapnenaca bili su statistički značajno niže od kalkokambisola povrh dolomita duž cijelog profila. Nije utvrđena značajna razlika u udjelima Corg i Ntot između kalkokambisola povrh vapnenaca i dolomita pa tako nema ni velike razlike u omjeru C/N. Prosječni odnos C/N duž cijelog profila kalkokambisola povrh vapnenaca i dolomita iznosi 14, odnosno dekompozicija traje neometano. Ovim istraživanjem je utvrđeno da postoje značajne razlike u ektomorfološkim (stjenovitost i kamenitost) i endomorfološkim (granulometrijski sastav tla, pH-vrijednost tla i udjel CaCO3) svojstvima kalkokambisola na različitim matičnim supstratima.
Calcocambisol (brown soil on limestone and dolomite) is one of the most common soil types in Croatia, and it is the dominant soil type developed on karst, as well as in the area of the Plitvice Lakes National Park, which is located in the karst area. As its name suggests, calcocambisol is developed on different carbonate substrates, which are different in terms of chemical composition as well as in terms of rock erosion. In the area of the National Park, 30 pedological profiles have been opened, 18 of which were on limestone and 12 on dolomite. In the field, ectomorphological and endomorphological soil parameters were determined. The following parameters were determined on the collected soil samples in the humus-accumulative (A) and cambic (B) horizons: particle size distribution of the soil, soil reaction, i.e. pH-value in water and CaCl2 solution, carbonate content, and total carbon and total nitrogen content using the dry burning method. The highest differences in ectomorphological parameters between limestone and dolomite were found in the classification of rockiness and stoneness, where they ranged from very low to very high on limestone, while they were absent on dolomite. On the profiles of calcocambisol on top of dolomite, a higher proportion of sand fractions and less clay than on calcocambisol on top of limestones was found. The dominant soil textural class of calcocambisol on top of limestone was silty clay, while in calcocambisol on top of dolomite it was silty clay loam. The pH-values of the soil and the proportion of CaCO3 on calcocambisol on top of dolomite were statistically significantly higher than on calcocambisol on top of limestone. Since there was no great difference in the fractions of organic carbon and total nitrogen between calcocambisol on top of limestones and dolomites, there was also no great difference in the C/N ratio. The average C/N ratio along the entire profile of calcocambisol on top of limestone and dolomite was 14, i.e. decomposition continued undisturbed and there was no accumulation of raw humus. The hypotheses in this paper were confirmed, and clear differences in the investigated ectomorphological (rockiness and stoniness) and endomorphological (particle size distribution, pH-values and CaCO3 content) properties between calcocambisol on top of limestone and dolomite were observed.
Visokogorsko područje dinarskog krša obilježeno je raznolikošću reljefnih formi, koje su u kombinaciji s humidnom klimom i različitim odnosima dolomita i vapnenaca, posebice u pogledu brzine i načina ...trošenja, dodatni izvor varijabilnosti fiziografije tla. U Nacionalnom parku Risnjak dimenzijama se ističu dvije ponikve (Viljska ponikva - VIP i Velika ponikva - VP) gdje smo testirali hipotezu o postojanju značajnih razlika u fiziografiji površinskog dijela tla. Cilj je bio istražiti u kojoj se mjeri uzduž osojne i prisojne padine ponikve mijenjaju kemijske značajke površinskog dijela tla i očituje li se pri tomu i razlika između dviju ponikvi, s obzirom na postojanje razlike u njihovoj litološkoj građi i poziciji unutar gorskog masiva. Istraživanja su provedena tako da je u svakoj ponikvi postavljen transekt u pravcu ~sjever-jug preko dna ponikve, na komu je obavljeno uzorkovanje tla do dubine od 15 cm (ili do stijene, ako je tlo pliće). Pokazalo se da je u VIP izraženija diferencijacija prirode humusa u organičnom horizontu i da ona dobro korespondira s diferencijacijom vegetacije. U VP se fizička trošivost stijena (dolomitični supstrat) odražava na fiziografiji tla u obliku karbonatnosti i više pH-vrijednosti, koja u VIP raste od dna prema rubu ponikve, dok se u VP pH-vrijednost značajno ne mijenja uzduž padina. Na osojnoj ekspoziciji u VIP je udio organskog ugljika u tlu značajno veći (377 g kg–1) od udjela na prisojnoj ekspoziciji (97 g kg–1), pri čemu na osojnoj ekspoziciji udio organskog ugljika opada od dna prema rubu ponikve, a na prisojnoj ekspoziciji se očituje blagi rast. Za razliku od navedonoga, u VP udjel organskog ugljika ima obrnuti trend. Slične odnose i trendove pokazuje i udjel ukupnog dušika, osim pri dnu osojne padine u VIP, gdje je Ntot relativno nizak, a Corg relativno visok.
Zaključno, fiziografija tla dubokih gorskih ponikvi krša pod snažnim je utjecajem prirode stijena u pogledu dolomitičnosti. Tlo povrh dolomita i dolomitičnih vapnenaca obilježeno je karbonatnošću. U ponikvama u masivima čvrstih vapnenaca može se očekivati na njihovim osojnim padinama karakteristične trendove pH-vrijednosti tla te udjela organskog ugljika i ukupnog dušika zbog vrlo izraženog hidrotermičkog, odnosno bioklimatskog trenda. Na prisojnim ekspozicijama takvih ponikvi analogni trendovi s karakterističnim gradijentima izostaju, što korespondira i s izostankom prepoznatljivog vegetacijskog slijeda.
The high mountain area of the Dinaric karst is characterized by a variety of relief forms, which in combination with humid climate and different relationships of dolomite and limestone, especially in terms of rate and nature of weathering, are an additional source of variability of soil physiography. In the Risnjak National Park, two sinkholes stand out in terms of dimensions (Viljska ponikva - VIP and Velika ponikva - VP), where we tested the hypothesis of the existence of significant differences in the physiography of the surface part of the soil. The aim was to investigate the extent to which the chemical characteristics of the surface part of the soil change along the shady and sunny slopes of the sinkhole and whether the difference between the two sinkholes is evident, given the difference in their lithological structure (VIP is sinkhole in limestone and VP is sinkhole in dolomitic limestones and calcite dolomites) and positions within the mountain massif. The research was carried out in such a way that in each sinkhole a transect was placed in the direction north-south over the bottom of the sinkhole, on which soil sampling was performed to a depth of 15 cm (or to the rock, if the soil is shallower). Sampling was performed on rows of profiles in 5 replicates, which were placed perpendicular to the transect with a height difference of 10 m (Fig. 1). In each sinkhole, 22 rows of profiles were set up, on which 110 soil samples were collected, and the pH value, carbonate content, organic carbon content and total nitrogen content were measured on them. The research showed that on the shady slope in VIP, in addition to vertical vegetation differentiation, there is also a differentiation of the nature of humus in the organic horizon (hemimor, modermor, sphagnomor). This differentiation is much less pronounced in the VP, and on the sunny slope in both sinkholes it is almost absent. In VP, the physical weathering of rocks (dolomitic substrate) is reflected in the physiography of the soil in the form of free carbonate and higher pH values (Figs. 9 and 10). In VIP the pH rises from the bottom towards the edge of the sinkhole, both on the shady and sunny slope, while in VP the pH value does not change significantly, both along the shady and along the sunny slope. A recognizable factor in the spatial variability of carbonate content and pH value of this soil is phytopedoturbation in the form of tree felling and ejection of carbonate particles on the surface of the sinkhole slope, where they are exposed to gravitational and water erosion and further redistribution down the slope.
At the shady slope in VIP, the share of organic carbon in the soil is significantly higher (377 g kg – 1) than the share at sunny slope (97 g kg – 1). At the shady slope the share of organic carbon decreases from the bottom to the edge of the sinkhole (Fig. 11), and a slight increase is evident on the sunny slope. In VP, the mean values on the slopes and the trends of these shares on the slopes in relation to VIP have the opposite relationship (Fig. 12). Similar relatios and trends are shown by the share of total nitrogen (Fig. 13), except at the bottom of the shady slope in VIP. Here, the share of Ntot is relatively low, and the share of Corg is relatively high, so only in this part within both transects does C/N differ significantly from the remaining parts of the transects (Fig. 14).
In conclusion, the soil physiography of deep karst sinkholes is strongly influenced by the nature of the rocks in terms of dolomiticity. The soil above the dolomite and dolomitic limestones is marked by carbonates. In deep sinkholes in solid limestone massifs, characteristic trends of soil pH and the content of organic carbon and total nitrogen can be expected on their shady slopes due to a very pronounced hydrothermal and bioclimatic trend. Analogous trends with characteristic gradients are absent on the sunny slopes of such sinkholes, which corresponds to the absence of a recognizable vegetation sequence.
A quantitative analysis of pedo-physiological indicators aimed at determining changes in the soil attributable to the effects of spruce plantations was done. The study was conducted at eight sites in ...central and north-western Croatia where spruce plantations were planted in the late 20th century. At each site, a pedological profile was opened within the spruce plantation and the endo-morphological parameters of the soil were determined. Composite soil samples from two depths (0-10 cm and 10-20 cm) and from the forest floor were taken in the spruce plantation and compared with samples taken at plots covered by natural vegetation (natural stands) located in the surroundings. The following pedo-physiographic indicators were measured on the collected soil samples: quantity of forest floor, particle size distribution of soil, pH values in H2O and in CaCl2 aqueous solution (concentration 0.01 mol dm-3), content of Corg, content of Ntot and content of bioavailable nutrients (using the Mehlich III method). The results showed that the forest floor had a higher mass in the spruce plantations than in natural stands. The mineral soil showed clear trends of influence of the spruce plantations on soil in terms of reduced pH values. Most plots in the spruce plantations showed a lower nitrogen content in the soil, a higher C/N ratio and lower content of bioavailable phosphorus. This study provides an insight into the amelioration effects of spruce plantations on soil, and represent a reliable basis for decision-making in planning specific interventions in terrestrial ecosystems, such as the establishment of new forest plantations.
Background and Purpose: This paper deals with the results of the investigation of the selected heavy metal contents in forest soil in the region of an abandoned mine. The analysis of the forest ...ecosystem soil on the Medvednica Mountain was conducted in the region of the so-called “French Mines” (FM). The elements selected for analyses were cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) because of their toxicological characteristics.
Material and Methods: In the investigated area - five entrances of the FM - composite topsoil samples (0–5 cm) were taken. Those samples were compared to the control samples which were taken outside the area affected by mines. The soil samples were analysed for the following parameters: pH, particle size distribution, organic C content and pseudo-total mass fractions of the selected heavy metals. The heavy metals were determined by atomic emission spectrometry with inductively coupled plasma (ICP-MS).
Results and Conclusion: The results reveal that the soil is locally polluted, i.e. the highest mass fraction values of these four heavy metals were found in the area of the FM. Average pseudo-total fraction of Cd in the analysed topsoil samples was in the range of 0.17–4.41 mg·kg−1 (median: 0.97 mg·kg−1). Cu was found in the range of 4.54–1260 mg·kg−1 (median: 45.7 mg·kg−1). In the case of Zn, mass fraction values were found in the range of 36.8–865 mg·kg−1 (median: 137 mg·kg−1). Finally, average values of the pseudo-total fraction of Pb were found in the range of 58.4–12000 mg·kg−1 (median: 238 mg·kg−1). The results reveal that mining activities leave consequences on soil for a long time.
Sažetak
Brojna istraživanja pokazuju da su šume obične jele ugrožene klimatskim promjenama, posebice na južnim rubovima njihova rasprostranjenja gdje su negativni učinci zatopljenja izraženiji. Šume ...jele i crnoga graba rastu od 850 m do 1150 m nadmorske visine na kontinentalnoj padini planine Biokovo na karakterističnom vrtačastom reljefu, koji utječe na mozaični raspored golih stijena, tla, vegetacije i šumske prostirke. Cilj ovoga istraživanja je, po prvi puta, za termofilne i najjužnije šume jele i crnoga graba u Hrvatskoj utvrditi fiziografske značajke šumske prostirke i tla te sadržaj teških metala u površinskom sloju tla, pa usporediti dobivene podatke za šumsku prostirku i tlo s podacima za ostale jelove zajednice Hrvatske. Terenskim opažanjima u nizu vrtača utvrđeno je da ljeti (sušno i toplo razdoblje) iz jamskih otvora i pukotina struji hladan zrak, stvarajući u vrtačama specifične mikroklimatske uvjete koji pogoduju jeli i mogu potencijalno biti važan čimbenik njenog opstanka. U šumi jele i crnoga graba utvrđene su značajne količine šumske prostirke i zalihe ugljika, koje su u rasponu od 2,86 kg m–2 do 11,59 kg m–2, odnosno od 1,13 kg m–2 do 4,89 kg m–2 uz izrazitu prostornu varijabilnost. Po fiziografskim značajkama površinskog sloja tla šume jele i crnoga graba grupiraju se uz bukovo-jelove šume sjevernog Velebita i Gorskog kotara, što upućuje na dominantan pedogenetski utjecaj (karbonatnog) matičnog supstrata. Osnovni limitirajući čimbenik tla šuma jele i crnoga graba njegova je mala dubina. U površinskom sloju tla utvrđen je povišen do vrlo visok sadržaj teških metala Cu, Pb, Zn, Ni i Cd.
Summary
Climate change is affecting the availability of resources and conditions critical to the life and survival of forest communities and the species that inhabit them, especially at the edges of their distribution. Numerous studies indicate that fir forests are threatened by climate change, especially at the southern edges of their range where the negative effects of warming are more pronounced.
The aim of this study was to determine for the first time for the thermophilic and southernmost fir and hornbeam forests (
Ostryo-Abietetum
) in Croatia the physiographic characteristics of the forest floor and soil, as well as the content of heavy metals in topsoil layer, and to compare the obtained data for the forest floor and soil with data for other fir communities in Croatia. These forests grow from 850 m to 1150 m a.s.l. on the continental slope of Biokovo Mountain on a characteristic sinkhole relief which influences the mosaic arrangement of soil, vegetation and forest floor.
Field observations in a number of sinkholes have shown that in summer (the dry and hot period) cold air flows in from caves and cracks and creates specific microclimatic conditions in the sinkholes that are favourable for fir and could be a key factor for its survival.
At the bottom of the sinkholes, fir trees dominate, rockiness is less pronounced and Mollic Leptosol and Leptic Cambisol alternate. The forest floor mass (load) is higher. On the other hand, at the edges of the sinkholes, the rockiness is more pronounced, the soil is either very shallow (Mollic Leptosol) or absent, and the forest floor mass is lower. Thermophilic tree species dominate, while firs are sporadic or absent.
Considerable amounts of forest floor and carbon stocks were determined in the fir and hornbeam forests, ranging from 2.86 kg m-2 to 11.59 kg m-2 and 1.13 kg m-2 to 4.89 kg m-2, respectively, with high spatial variability. According to the physiographic characteristics of the surface layer of the soil, fir and hornbeam forests are grouped together with the beech-fir forests of the northern Velebit and Gorski kotar, indicating the dominant pedogenetic influence of the (carbonate) parent substrate. The basic limiting factor of the soil of fir and hornbeam forests is its shallow depth. Elevated to very high content of the heavy metals Cu, Pb, Zn, Ni and Cd were found in the topsoil.
Odumiranjem stabala mijenjaju se stanišne prilike u šumskom ekosustavu, uslijed čega dolazi do promjene mikroklime i mikrobiološke aktivnosti tla. Cilj ovoga istraživanja je utvrditi razlike u ...mikroklimi staništa te u enzimatskoj aktivnosti šumskog tla u trima šumskim progalama i trima šumskim sastojinama obične jele s rebračom (Blechno-Abietetum Ht. 1950). Od mikroklimatskih elemenata mjerene su temperatura zraka, temperatura tla, relativna vlažnost zraka i volumetrijska vlažnost tla. Za određivanje kemijskih svojstava tla te dehidrogenazne i proteolitičke aktivnosti tala prikupljeni su kompozitni uzorci tla s dubine od 0 do 10 cm. U šumskim progalama utvrđene su značajno više vrijednosti temperatura zraka i tla te značajno niže vrijednosti relativne vlažnosti zraka i volumetrijske vlažnosti tla nego u šumskoj sastojini. Provedenim istraživanjem nisu utvrđene značajne razlike u kemijskim svojstvima tala između šumskih progala i sastojina. Zbog nesignifikantnih promjena kemijskih karakteristika tla, nisu utvrđene značajne promjene u enzimatskoj aktivnosti tala u progalama u odnosu na šumske sastojine. Temperatura zraka i temperatura tla povezane su s dehidrogenaznom aktivnosti tala, dok su temperatura tla i volumetrijska vlažnost tla povezane s proteolitičkom aktivnosti tala u šumskim progalama. Kemijska su svojstva tla također imale značajan utjecaj na enzimatsku aktivnost, jer se povećanjem udjela organske tvari, dušika, humusa i ugljika u tlu povećava i enzimatska aktivnost šumskih tala. Najveće korelacije enzimatske aktivnosti i kemijskih svojstava tla utvrđene su za proteolitičku aktivnost šumskih tala. Enzimatska aktivnost šumskih tala bila je najveća na početku vegetacijskog razdoblja u uvjetima optimalne temperature i vlažnosti tla.
With the decline of trees, habitat conditions change, resulting in changes in the microclimate and microbiological activity of the soil. The aim of the research is to determine the differences in the microclimate of habitats and in the enzymatic activity of forest soil in three forest gaps and three forest stands of silver fir with hard fern (Blechno-Abietetum Ht. 1950). Of the microclimatic elements, air temperature, soil temperature, relative air humidity and volumetric soil moisture were measured. Composite soil samples from a depth of 0 to 10 cm were collected to determine the chemical properties of the soil and the dehydrogenase and proteolytic activity of the soil. Significantly higher values of air and soil temperatures and significantly lower values of relative air humidity and volumetric soil moisture were found in forest gaps. The research did not reveal any differences in the chemical properties of the soil between forest gaps and stands. Due to insignificant changes in soil chemical characteristics, no significant changes in soil enzymatic activity were found in the gaps in relation to forest stands. Air temperature and soil temperature are related to soil dehydrogenase activity, while volumetric soil moisture is associated with proteolytic soil activity in forest gaps. Soil chemical characteristics also had a significant effect on enzymatic activity. By increasing the share of organic matter, nitrogen, humus and carbon in the soil, the enzymatic activity of forest soils also increases. The highest correlations between enzymatic activity and soil chemical characteristics were found for proteolytic activity of forest soils. The enzymatic activity of forest soils was highest at the beginning of the vegetation period under conditions of optimal soil temperature and soil moisture.
PDF
