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Baksic D.,University of Zagreb | Perkovic I.,University of Zagreb | Pernar N.,University of Zagreb | Vukelic J.,University of Zagreb | Vrbek B.,Hrvatski sumarski Institute Jastrebarsko
Croatian Journal of Forest Engineering | Year: 2011

The largest and the most coherent complexes of natural spruce stands in Croatia are currently distributed in the altimontane and subalpine vegetation belt of Velebit over an area of 3165 ha and altitudes ranging from 1100 to almost 1600 m. Past phytocoenological research into spruce forests in northern Velebit distinguishes three different associations: frost valleys of Štirova~a and Apati{anska Duliba support the altimontane spruce forest with bastard agrimony (Aremonio-Piceetum Horvat 1938), shallower sink holes and slopes descending from the surrounding tops contain the altimontane-subalpine spruce forest with Laserpitium krapfii (Laserpitio krapfii-Piceetum Vukeli} et al. 2010), while rocky tops, hips, karrens and ridges feature the subalpine spruce forest with small-reed (Calamagrostio variae-Piceetum Bertovi} 1975). These associations are distributed as azonal, microclimatically and edaphically conditioned associations, of which spruce forest with bastard agrimony occurs in the belt of Dinaric beech-fir forest (Omphalodo-Fagetum) while the two others grow in a higher belt ofsubalpine beech forest with buttercup (Ranunculo platanifoliae-Fagetum). Their mutual differences result from ecological factors which are decisive for their occurrence and distribution. Of these, the edaphic relationships which we explored in this work draw particular interest. Composite samples were taken from the top layer up to 5 cm deep (13 composite samples composed of 9 individual samples each), pedological profiles were opened (11 profiles), and soil samples were taken by pedogenetic horizons within pedological research in three spruce communities: altimontane spruce forest with bastard agrimony (Aremonio-Piceetum), altimontane-subalpine spruce forest with Laserpitium krapfii (Laserpitio krapfii-Piceetum), and subalpine spruce forest with small-reed (Calamagrostio-Piceetum) in the area of northern Velebit and Štirova~a. Composite samples, taken from the top soil layer up to 5 cm deep, consisted of 9 samples, each taken at a distance of 1 m in a cross pattern. Soil samples were analyzed by means of the following laboratory methods: determination ofpH values (HRN ISO 10390:2005), determination ofCaCO 3 content (HRN ISO 10693:2004), determination of organic and total carbon and nitrogen with dry combustion (HRN ISO 10694:2004, HRN ISO 13878:2004), determination of concentrations ofPb, Zn, Cu and Cd (HRN ISO 11466:2004), and determination of the granulometric soil composition (HRN ISO 11277:2004). Descriptive statistics were made for all the samples by the investigated phytocoenosis. Variance analysis was used to test the differences between the composite soil samples for the layer of up to 5 cm in depth. Statistica 7.0 software was used for this purpose. The analyses of composite soil samples taken from a depth of 5 cm in three different spruce communities (Aremonio-Piceetum, Laserpitio krapfii-Piceetum and Calamagrostio-Piceetum) showed than the lowest pH value was recorded in the community Aremonio-Piceetum, followed by the community Calamagrostio-Piceetum, while the highest value was recorded in the community Laserpitio krapfii-Piceetum. The average pH (H 2O) value in the community Aremonio-Piceetum reaches 4.35, in Laserpitio krapfii-Piceetum it is 5.56 and in Calamagrostio-Piceetum it is 5.23. In terms ofpH values for soil depths of up to 5 cm, the communities Aremonio-Piceetum and Laserpitio krapfii-Piceetum (pH H 2O, p=0.01447; pH CaCl 2, p=0.01668) show a statistically significant difference. In all the communities the surface soil layer is richly humous and well supplied with nitrogen. It is the richest in the community Calamagrostio-Piceetum, where the average value of C org amounts to 131.6 g kg -1 and N tot. to 9.3 g kg -1 (Table 3). The C: N ratio in all the three communities is favourable and ranges between 11 and 15. The average depth of the humus-accumulative horizon amounting to 6.5 cm is the lowest in the community Aremonio-Piceetum. It is higher in the community Laserpitio krapfii-Piceetum where it reaches 7.5 cm and the highest in the community Calamagrostio-Piceetum, where it is 21 cm. The content ofpH values, C org., N tot. in the hummus-accumulative horizon shows similar values and an identical trend to composite soil samples at a depth of up to 5 cm. In terms of the argyle-accumulative and cambic horizon, the lowest pH value is observed in the community Aremonio-Piceetum, where the average pH (H 2O) value is 5.30. In the community Laserpitio krapfii-Piceetum, the average pH (H 2O) value is 6.92. The highest pH value is observed in the community Calamagrostio-Piceetum, where the average pH (H 2O) value reaches 7.21, but it is only one profile opened in the shallow and distinctly skeletal calcocambisol. All the soils have a texture ranging from silty to clayey loam. Soil reaction was the only parameter to show statistically significant differences for the top soil layer. These differences relate to the communities Aremonio-Piceetum and Laserpitio krapfii-Piceetum. The lowest pH value in the community Aremonio-Piceetum is conditioned by acid parent material, flat relief which additionally favours the podzolization process in the perhumid climate, while specific microclimatic conditions, frost sites and high air humidity cause more intensive accumulations of raw humus. In relation to the pH reaction, the lowest acidity is displayed by the association Laserpitio krapfii-Piceetum, as confirmed by phytocoenological research (Vukeli} et al. 2010), according to which this community, compared to others, has the biggest number of species of the order Fagetalia. These species are dominant in adjacent, mainly neutrophilic beech and beech-fir forests. All the three studied communities, Aremonio-Piceetum, Laserpitio krapfii-Piceetum and Calamagrostio-Piceetum, manifested high Pb contamination in the surface soil layer of up 5 cm. The average Pb content (median) in the community Aremonio-Piceetum amounts to 54.5 mg kg -1, in the community Laserpitio krapfii-Piceetum to 65.0 mg kg -1, and in the community Calamagrostio-Piceetum to 54.7 mg kg -1. The top soil layer of 5 cm in the communities Laserpitio krapfii-Piceetum and Calamagrostio-Piceetum also manifested high Zn and Cd contamination. The average content (median) in the community Laserpitio krapfii-Piceetum for Zn is 101.0 mg kg -1 and for Cd it is 1.0 mg kg -1, whereas in the community Calamagrostio-Piceetum it is 75.0 mg kg -1 for Zn and 1.9 mg kg -1 for Cd.


Diminic D.,University of Zagreb | Jazbec A.,University of Zagreb | Zupanic M.,Hrvatski sumarski Institute Jastrebarsko
Croatian Journal of Forest Engineering | Year: 2011

In the region of Gorski Kotar 6 sites (localities) of Silver fir (Abies alba Mill.) were selected to investigate the health status of trees, the infestation by common mistletoe (Viscum album L. ssp. abietis /Wiesb./ Abromeit), and to reveal the nutrition status of fir trees and mistletoes. Three localities were selected on soil sub-types based on silicate and three on limestone-dolomite (Table 1). In the period 2003-2005, from the end of September to the beginning of November, 15 fir trees were randomly selected on each site and evaluated according to crown defoliation with a 5% precision using the criteria and methods of UN/ECE ICP Forests. The diameter of the selected trees was measured at breast height. The trees height and their age on stumps were determined after felling. The crowns were examined in detail; the mistletoes were removed and counted to reveal the number of parasitic plants, and weighed to obtain their crown biomass per each site (Tables 2-7). This paper presents the analyses of 90 trees in total. Samples of fir needles and mistletoe leaves were collected for nutrition analyses from the upper 1/3 of the crown. Needle samples (1and 2-year old) were dried at 105°C, weighed, and analyzed for the total amount of nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese and zinc. In total, the results are given of the analyses of 180 needles and 17 mistletoe samples. In October 2008 the repeated collection of needle samples was carried out on the same sites in 5 fir trees of a good vitality with crown defoliation <25%. Each site was represented by a composite sample of 1and 2-year old needles. The same procedure was performed to analyze samples. Soil samples were also taken as composite samples for each site from two soil depths 0-30 and 30-60 cm, using the Holland drill. Standardized soil analyses were performed to obtain the total nitrogen, plant available phosphorus and potassium, and for the determination of pH. Descriptive statistics was made for all analyzed variables. For all tests, the error of type I (a) of 5% was considered as significant difference. Statistical analyses of variables were performed as follows: one factor analysis of variance for number of mistletoes and mistletoe biomass according to locality and soil sub-type, two factor analysis of variance for concentration of elements in fir needles and mistletoe leaves according to soil sub-types, repeated measures analysis of variance for concentration of elements in fir needles according to soil sub-types and needles age, repeated measures analysis of variance for chemical analyses of two soil sub-types and two soil depths (0-30, 30-60 cm) (Sokal and Rohlf 1995). Statistical analyses and graphics were done using the software STATISTICA 7.1 (StatSoft, Inc. 2010). The research revealed differences in fir trees with mistletoe infestation. Fig. 1 and 2, and Table 8 show the results of statistical analyses of the number of mistletoes and their biomass in fir crowns. The differences revealed between localities are not statistically significant. These results also confirmed previously published data (Dimini} i Kauzlari} 2006) that with the increment of crown defoliation the number of mistletoes and their biomass increase in fir trees as well. The general picture of infestation, comparing the sites on two soil sub-types, revealed slightly more infested trees on limestone-dolomite, in number and mistletoe biomass. However, during our research the most infested firs revealed 417, 421 and 491 mistletoes in the trees grown on silicate soils, while in trees on limestone-dolomite soils the most infested firs revealed 205, 303 and 364 mistletoes. According to biomass, the most affected fir had 52.4 kg of mistletoes in the tree on silicate soil, and 52.3 kg in the tree on limestone-dolomite soil. Statistical analyses of data on nutrition status in firs and mistletoes revealed no significant difference generally, although some trends could be seen (Fig. 5, Table 9). Significant difference was obtained by comparing fir needles and mistletoe leaves in N, P, K and Zn, which was expected as two different plant organisms were compared. In the case of other elements no significant difference was found. The same result was obtained in two different soil sub-types, except in phosphorous concentrations (Fig. 5, Table 9). The nutrition status of mistletoe expectedly followed nutrition status of its host, and the differences in concentration of elements according to type of substratum (soil sub-type) were almost identical in needles and mistletoe leaves, with respect to differences in absolute values. Comparing the limited values with average values of a single analyzed element according to the soil sub-type, concentrations of nitrogen in fir trees were not adequate on limestone-dolomite but they were adequate on silicate. Phosphorous concentrations were not adequate, neither on limestone-dolomite nor on silicate, which correlates to the low contents in the sampled soils. Concentrations of potassium were adequate on both soil sub-types, and calcium and magnesium optimal. Analyses of 1and 2-year old fir needles (repeated sampling) revealed similar results (Fig. 6, Table 10). The differences among results in nutrition status of 15 and 5 sampled trees were not significant, and they can be explained by annual fluctuations. Analyses of soil samples of two soil sub-types revealed the expected significant statistical difference in pH, where soils on silicate had lower reaction. Analyses of total nitrogen, plant available phosphorus and potassium in the soils revealed no significant difference (Fig. 7, Table 11). The research on fir trees with mistletoe infestation in the region of Gorski Kotar revealed some facts. Intense infestation was found in five of six investigated sites, intensity of mistletoes presence as well as their biomass in fir crowns correlated to crown defoliation, and the nutrition status of mistletoe expectedly followed nutrition status of its host, with respect to differences in absolute values.


Baksic D.,University of Zagreb | Pernar N.,University of Zagreb | Perkovic I.,University of Zagreb | Vrbek B.,Hrvatski sumarski Institute Jastrebarsko | Roje V.,University of Zagreb
Sumarski List | Year: 2015

Alkali earth metals and alkali metals Ca, Mg, K and Na are a constituent part of the lithosphere rocks and belong among the 8 most abudant elements in the Earth's crust. They are the results of the weathering of rocks on the surface of the Earth's crust in the process of pedogenesis. From the aspect of plant nutrition, these elements belong to plant nutrients: K, Ca and Mg belong to macro-elements or essential elements, while Na belongs to beneficial elements. The goal of this research is to establish how the lithological bedrock, or parent material in the area of Medvednica Nature Park affects the Ca, Mg, K and Na content in the soil, and whether their spatial distribution is conditioned by the relief as well as by the lithological bedrock. A total of 181 composite samples were taken in the Medvednica NP forests. Topsoil samples to a 5 cm depth were taken in a regular 1 x 1 km grid. Twenty-eight pedological profiles were opened and evenly distributed to encompass all lithological units. Soil pH values (HRN ISO 10390:2005) were measured in topsoil samples and so was the content of the elements Ca, Mg, K, and Na after extraction with aqua regia (HRN ISO 11466:2004). Determination of particle size distribution in mineral soil material (HRN ISO 11277:2004), de termination of soil pH ( HRN ISO 10390:2005), determination of organic carbon and total nitrogen after dry combustion (HRN ISO 10694:2004; HRN ISO 13878:2004), mineral content of the soil (XRD) by X-ray diffraction method and content of the elements Ca, Mg, K and Na after extraction with aqua regia (HRN ISO 11466:2004) were determined in the samples taken from genetic horizons in the pedological profiles. For statistical purposes, the lithological bedrock was divided into seven characteristic lithological units, which were used by geologists Halamić et al. (2001) in their study of stream sediments on Medvednica. Lithological unit LIT1 is made up of parametamorphic rocks, Lithological unit LIT2 is composed of orthometamorphic rocks, Lithological unit LIT3 consists of igneous rocks, Lithological unit LIT4 is formed of Mesozoic clastic rocks, Lithological unit LIT5 is comprised of Tertiary clastic rocks, Lithological unit LIT6 consists of Mesozoic carbonate rocks and Lithological unit LIT7 is made up of Tertiary carbonate rocks. Statistical analysis was performed in Statistica 7 software package. Descriptive statistics was made for all the analyzed variables: number of samples, minimum, lower quartile, median, upper quartile, maximum, mean, standard deviation, coefficient of variation, standard error of mean and skewness. In order to eliminate the effect of outliers and extreme values, the median was taken as the mean value. Mutual differences between the analyzed values per lithological bedrock were tested using the Kruskal-Wallis non-parametric test. Type 1 (a) error of 5% was considered statistically significant. The highest pH value was recorded for the topsoil layer in LIT6 and LIT7. LIT6 has statistically significantly higher pH value than LIT1, LIT2, LIT3, LIT4 and LIT5, while LIT7 has statistically significantly higher pH value than LIT2, LIT4 and LIT5. Statistically significant positive correlation between pH values and Ca concentrations were found in all lithological units. Statistically significant positive correlation between pH values and Mg was also established for LIT1 and LIT5, and between pH values and K for LIT2 and LIT4. In terms of Mg concentration, two groups were clearly identified: one consisting of LIT4, LIT5 and LIT7 with lower concentration, and the other comprising LIT2, LIT3 and LIT6 with higher concentration, while LIT1 is between the two groups. The following soil types were determined in the opened pedological profiles: dystric cambisol, eutric cambisol, calcocambisol, pseudogley on slope, colluvium and luvisol (50% - 18% - 14% - 11% - 4% - 4%). In general, the humus-accumulative horizon on Mt Medvednica is shallow - The median is 3.3 cm, and the mean is 3.9 cm. The next horizon, which is usually cambic, is 31 cm and 33 dm thick. The range of organic C content in the humus accumulative horizon ranges from medium humic to very humic soil. The soil is rich to very rich in total nitrogen, and the C/N ratio is favourable. The soil texture is most frequently silty loam, while on the carbonate bedrock it is of somewhat heavier - silty clay loam. The content of individual minerals, and of Ca, Mg, K and Na in the humus-accumulative and mineral horizon is more or less equal, while the correlation between the horizons is statistically significant (p<0,01). For quartz it is r = 0.81, muscovite/illite r = 0,68, chlorite r = 0,76, feldspate r = 0,69, Ca r = 0,85, Mg r = 0,88, K r = 0,82 and Na r = 0,52. The highest pH values and Ca, Mg, K and Na concentrations in beech-fir forests were recorded in the surface soil layer at a depth of 5 cm in LIT3. A statistically significant difference in Ca concentration was found between LIT3 and LIT2 and in Na concentration between LIT3 and LIT1. The obtained Ca and Mg concentrations in the topsoil of Medvednica Nature Park are in accordance with the values recorded in Central Croatia by Halamić and Milko during their work on the Geochemical Atlas of the Republic of Croatia (2009). The data for all the obtained elements concord with the results obtained from a study of the condition of forest soils in Europe (Vanmechelen et al., 1997). The relief (elevation, inclination, exposition, curvature) do not affect the spatial distribution of Ca, Mg and Na in the topsoil to a depth of 5 cm. Although there is a statistically significant correlation between elevation and Mg concentration, and slope and Mg concentration, this correlation is actually conditioned by the lithological bedrock. Beech-fir stands developed on the soils above basic igneous rocks are characterized by a higher Ca, Mg, K and Na content, and consequently higher pH values. As a result, a higher number of neutrophilic species can be expected in these forests.

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